2652661
Treatment of Thrombotic Antiphospholipid Syndrome: The Rationale of Current Management—An Insight into Future Approaches
Vascular thrombosis and pregnancy morbidity represent the clinical manifestations of antiphospholipid syndrome (APS), which is serologically characterized by the persistent positivity of antiphospholipid antibodies (aPL). Antiplatelet and anticoagulant agents currently provide the mainstay of APS treatment. However, the debate is still open: controversies involve the intensity and the duration of anticoagulation and the treatment of stroke and refractory cases. Unfortunately, the literature cannot provide definite answers to these controversial issues as it is flawed by many limitations, mainly due to the recruitment of patients not fulfilling laboratory and clinical criteria for APS. The recommended therapeutic management of different aPL-related clinical manifestations is hereby presented, with a critical appraisal of the evidence supporting such approaches. Cutting edge therapeutic strategies are also discussed, presenting the pioneer reports about the efficacy of novel pharmacological agents in APS. Thanks to a better understanding of aPL pathogenic mechanisms, new therapeutic targets will soon be explored. Much work is still to be done to unravel the most controversial issues about APS management: future studies are warranted to define the optimal management according to aPL risk profile and to assess the impact of a strict control of cardiovascular risk factors on disease control.
17723499
Antiphospholipid syndrome in 2014: more clinical manifestations, novel pathogenic players and emerging biomarkers
The clinical spectrum of the anti-phospholipid syndrome (APS) is not limited to vascular thrombosis or miscarriages but includes additional manifestations that cannot be explained solely by a thrombophilic state. Anti-cardiolipin, anti-beta2 glycoprotein I (anti-β2GPI) and lupus anticoagulant (LA) assays are not only the formal diagnostic and classification laboratory tools but also parameters to stratify the risk to develop the clinical manifestations of the syndrome. In particular, anti-β2GPI antibodies reacting with an immunodominant epitope on domain I of the molecule were reported as the prevalent specificity in APS patients, correlating with a more aggressive clinical picture. Several laboratory assays to improve the diagnostic and predictive power of the standard tests have been proposed. Plates coated with the phosphatidylserine-prothrombin complex for detecting antibodies represent a promising laboratory tool correlating with LA and with clinical manifestations. Anti-phospholipid antibodies can be found in patients with full-blown APS, in those with thrombotic events or obstetric complications only or in asymptomatic carriers. An inflammatory second hit is required to increase the presence of β2GPI in vascular tissues, eventually triggering thrombosis. Post-transcriptional modifications of circulating β2GPI, different epitope specificities or diverse anti-β2GPI antibody-induced cell signaling have all been suggested to affect the clinical manifestations and/or to modulate their occurrence.
19202266
Antiphospholipid syndrome: clinical and immunologic manifestations and patterns of disease expression in a cohort of 1,000 patients.
OBJECTIVE
To analyze the clinical and immunologic manifestations of antiphospholipid syndrome (APS) in a large cohort of patients and to define patterns of disease expression.


METHODS
The clinical and serologic features of APS (Sapporo preliminary criteria) in 1,000 patients from 13 European countries were analyzed using a computerized database.


RESULTS
The cohort consisted of 820 female patients (82.0%) and 180 male patients (18.0%) with a mean +/- SD age of 42 +/- 14 years at study entry. "Primary" APS was present in 53.1% of the patients; APS was associated with systemic lupus erythematosus (SLE) in 36.2%, with lupus-like syndrome in 5.0%, and with other diseases in 5.9%. A variety of thrombotic manifestations affecting the majority of organs were recorded. A catastrophic APS occurred in 0.8% of the patients. Patients with APS associated with SLE had more episodes of arthritis and livedo reticularis, and more frequently exhibited thrombocytopenia and leukopenia. Female patients had a higher frequency of arthritis, livedo reticularis, and migraine. Male patients had a higher frequency of myocardial infarction, epilepsy, and arterial thrombosis in the lower legs and feet. In 28 patients (2.8%), disease onset occurred before age 15; these patients had more episodes of chorea and jugular vein thrombosis than the remaining patients. In 127 patients (12.7%), disease onset occurred after age 50; most of these patients were men. These patients had a higher frequency of stroke and angina pectoris, but a lower frequency of livedo reticularis, than the remaining patients.


CONCLUSION
APS may affect any organ of the body and display a broad spectrum of manifestations. An association with SLE, the patient's sex, and the patient's age at disease onset can modify the disease expression and define specific subsets of APS.
10281094
New Tests to Detect Antiphospholipid Antibodies: Anti-Domain I Beta-2-Glycoprotein-I Antibodies
Beta-2 glycoprotein I (β2GPI) is the main antigenic target for antiphospholipid antibodies (aPL), the serological markers of antiphospholipid syndrome (APS). Domain I (DI) of β2GPI has lately been identified as the main epitope targeted by antibodies reacting against β2GPI. DI is a cryptic epitope, becoming available for autoantibody binding when β2GPI opens from a circular to a fish-hook configuration. Antibodies targeting β2GPI-DI are more frequently detected in patients with a full-blown syndrome than in asymptomatic aPL carriers or in patients with infectious diseases that have reactivity toward the whole molecule. Interestingly, anti-DI antibodies are strongly positively correlated with thrombotic and pregnancy manifestations, enabling identification of patients at higher risk of clinical events. However, available tests to detect anti-DI antibodies still lack standardization. Moreover, some APS patients develop antibodies reacting against β2GPI epitopes other than DI, suggesting that other anti-β2GPI antibody subsets may be clinically relevant. Available evidence on anti-DI antibodies in APS is herein critically reviewed.
2262392
Pathogenesis of antiphospholipid syndrome: understanding the antibodies
Antiphospholipid antibodies (aPL) are both diagnostic markers for, and pathogenic drivers of, antiphospholipid syndrome (APS). Although the presence of aPL is a necessary pre-condition, APS-associated clotting is seemingly triggered by an additional 'second hit', frequently related to innate inflammatory immune responses. β2 glycoprotein I (β2GPI)-dependent aPL, the most important subset of these antibodies, mediate several—not necessarily alternative—thrombogenic mechanisms, mainly on the basis of their reactivity with β2GPI expressed on the membrane of cells that participate in the coagulation cascade. Recurrent pregnancy complications associated with aPL cannot be explained solely by thrombosis, and alternative pathogenic mechanisms have been reported. Although one in vivo model of fetal loss suggests a mechanism of aPL-mediated acute placental inflammation, other models and the histopathological examination of APS placentae do not support a widespread inflammatory signature. β2GPI-dependent aPL are thought to recognize their antigen on placental tissues, inhibit the growth and differentiation of trophoblasts, and eventually cause defective placentation. Why antibodies with similar antigen specificity produce different clinical manifestations is not clear. Characterization of the molecular basis of the pathogenic mechanisms involved, including the putative second hits and the role of complement activation, might offer an answer to this question.
6794850
Inhibition of the mTORC pathway in the antiphospholipid syndrome.
BACKGROUND
Although thrombosis is considered the cardinal feature of the antiphospholipid syndrome, chronic vascular lesions are common, particularly in patients with life-threatening complications. In patients who require transplantation, vascular lesions often recur. The molecular pathways involved in the vasculopathy of the antiphospholipid syndrome are unknown, and adequate therapies are lacking.


METHODS
We used double immunostaining to evaluate pathway activation in the mammalian target of rapamycin complex (mTORC) and the nature of cell proliferation in the vessels of patients with primary or secondary antiphospholipid syndrome nephropathy. We also evaluated autopsy specimens from persons who had catastrophic antiphospholipid syndrome. The molecular pathways through which antiphospholipid antibodies modulate the mTORC pathway were evaluated in vitro, and potential pharmacologic inhibitors were also tested in vitro. Finally, we studied the effect of sirolimus in kidney-transplant recipients with the antiphospholipid syndrome.


RESULTS
The vascular endothelium of proliferating intrarenal vessels from patients with antiphospholipid syndrome nephropathy showed indications of activation of the mTORC pathway. In cultured vascular endothelial cells, IgG antibodies from patients with the antiphospholipid syndrome stimulated mTORC through the phosphatidylinositol 3-kinase (PI3K)-AKT pathway. Patients with antiphospholipid syndrome nephropathy who required transplantation and were receiving sirolimus had no recurrence of vascular lesions and had decreased vascular proliferation on biopsy as compared with patients with antiphospholipid antibodies who were not receiving sirolimus. Among 10 patients treated with sirolimus, 7 (70%) had a functioning renal allograft 144 months after transplantation versus 3 of 27 untreated patients (11%). Activation of mTORC was also found in the vessels of autopsy specimens from patients with catastrophic antiphospholipid syndrome.


CONCLUSIONS
Our results suggest that the mTORC pathway is involved in the vascular lesions associated with the antiphospholipid syndrome. (Funded by INSERM and others.).
6229748
Estimated Frequency of Antiphospholipid Antibodies in Patients With Pregnancy Morbidity, Stroke, Myocardial Infarction, and Deep Vein Thrombosis: A Critical Review of the Literature
Antiphospholipid Syndrome Alliance For Clinical Trials and International Networking (APS ACTION) is an international research network devoted to conducting well‐designed clinical trials in persistently antiphospholipid antibody (aPL)–positive patients. One of the first needs of APS ACTION was to know the true aPL frequency in patients with pregnancy morbidity (PM), stroke (ST), myocardial infarction (MI), and deep venous thrombosis (DVT).
39344802
Lupus anticoagulants and the risk of a first episode of deep venous thrombosis
Summary.  We have determined lupus anticoagulants, anti‐β2 glycoprotein I (β2GPI) and antiprothrombin antibodies in the Leiden Thrombophilia Study, a population‐based case–control study designed to determine risk factors for deep venous thrombosis (DVT). Lupus anticoagulant (LAC) was measured in 473 patients and 472 control subjects. Four control subjects (0.9%) and 14 patients (3.1%) had a positive LAC, resulting in a 3.6‐fold increased risk [odds ratio (OR) 3.6, 95% CI: 1.2–10.9]. Of the total population, 49 were positive for anti‐β2GPI antibodies: 15 controls (3.4%) and 34 patients (7.5%), implying a 2.4‐fold increased risk (95% CI: 1.3–4.2). Antiprothrombin antibodies were present in 114 subjects: 48 controls (11.0%) and 66 cases (14.6%) with an OR of 1.4 (95% CI: 1.0–2.1). When LAC was considered in the co‐presence of antiprothrombin or anti‐β2GPI antibodies the OR increased to 10.1 (95% CI: 1.3–79.8). A LAC without a positive anti‐β2GPI or antiprothrombin test was not associated with a risk for DVT (OR 1.3, 95% CI: 0.3–6.0). This study demonstrates that the presence of LAC, anti‐β2GPI antibodies and antiprothrombin antibodies are risk factors for DVT in a general population. The strongest association holds for the combination LAC and the presence of anti‐β2GPI or antiprothrombin antibodies.
39966419
Risk factors for thrombosis and primary thrombosis prevention in patients with systemic lupus erythematosus with or without antiphospholipid antibodies.
OBJECTIVE
Antiphospholipid antibodies (aPL), namely anticardiolipin antibodies (aCL) and lupus anticoagulant (LAC), have been associated with an increased risk of thrombosis in systemic lupus erythematosus (SLE). We examined additional thrombosis risk factors (aPL profile, SLE-related, and traditional risk factors) and the primary thrombosis prevention in SLE patients with and without aPL.


METHODS
All SLE patients with positive aPL but without previous thrombotic manifestations who were regularly followed up at our department (n = 144) and 144 age- and sex-matched SLE patients with negative aPL were included in this study. The median followup times were 104 and 112 months, respectively. The demographic, clinical, laboratory, and treatment characteristics and the traditional thrombosis risk factors were recorded.


RESULTS
The thrombosis rate was 29 per 144 aPL-positive patients (20.1%) and 11 per 144 aPL-negative patients (7.6%; P = 0.003). In multiadjusted analysis, significant predictors of thrombosis were male sex (hazard ratio [HR] 6.25, P < 0.01), LAC (HR 3.48, P = 0.04), and constantly positive aCL (HR 5.87, P = 0.01) for aPL-positive patients, while male sex (HR 7.14, P = 0.03) and hypertension were predictors for aPL-negative patients (HR 6.49, P = 0.03). Additionally, the duration of low-dose aspirin treatment played a protective role against thrombosis in aPL-positive patients (HR per month 0.98, P = 0.05), as did the duration of hydroxychloroquine in both aPL-positive (HR per month 0.99, P = 0.05) and aPL-negative patients (HR per month 0.98, P = 0.04).


CONCLUSION
Independent predictors of thrombosis for aPL-positive patients were male sex, LAC, and constantly positive aCL, and for aPL-negative patients were male sex and hypertension. The duration of low-dose aspirin use played a protective role against thrombosis in aPL-positive patients as did the duration of hydroxychloroquine in both groups.
34742
Infectious origin of the antiphospholipid syndrome.
From a systemic disease towards the infectious aetiology

The general consensus is that autoimmune diseases have a multifactorial aetiology, depending on both genetic and environmental factors. Microbial agents or viruses can induce autoimmune diseases by a variety of mechanisms.1 For example, proteins of certain infectious agents can act as polyclonal activators on unique lymphocyte subsets. Viruses can preferentially infect/destroy a particular T cell subset, leading to an imbalance in the immune response. Several microbial agents have been found to encode superantigens that can selectively activate subset(s) of T cells. Microbes can also direct the release of cytokines and chemokines, which can act as growth, differentiation, or chemotactic factors for different cell populations and regulate expression of major histocompatibility complex class I and class II as well as costimulatory molecules.2

The healthy immune system is tolerant of the molecules of which the body is composed. However, one can find that among the major antigens recognised during a wide variety of bacterial, viral, and parasitic diseases, many belong to conserved protein families, sharing extensive sequence identity or conformational fits, with the host’s molecules—namely, molecular mimicry. Antigenic similarity of the linear amino acid sequences of either molecule or their conformational structure between antigens of infectious agents and host tissues might trigger an immune response against the shared determinant. As a result, the tolerance to autoantigens breaks down, and the pathogen-specific immune response that is generated, cross reacts with host structures to cause tissue damage and disease. A role for molecular mimicry in the pathogenesis of autoimmune diseases has recently been shown in several animal models such as allergic encephalomyelitis, experimental myocarditis, and experimental autoimmune uveitis and keratitis.2

The classical antiphospholipid syndrome (APS) is characterised by the presence of antiphospholipid antibodies (aPL) which bind target phospholipid molecules, mainly through β2 …
32126792
Bleeding and recurrent thrombosis in definite antiphospholipid syndrome: analysis of a series of 66 patients treated with oral anticoagulation to a target international normalized ratio of 3.5.
BACKGROUND
Prolonged anticoagulation is the treatment of choice for patients with thrombosis and the antiphospholipid syndrome. However, there is still debate about the optimum intensity of anticoagulation.


METHODS
The study included 66 patients with antiphospholipid syndrome (Sapporo criteria) and previous thrombosis. All were receiving oral anticoagulation to a target international normalized ratio of 3.5. Every patient was individually interviewed to recall major bleeding and thrombotic episodes during the previous 12 months.


RESULTS
Patients were mainly women and white. The rate of major bleeding was 6 cases per 100 patient-years (95% confidence interval [CI] 1.6-15.0). The rate of intracranial bleed was 1.5 per 100 patient-years (95% CI, 0.04-8.4). None of the bleeding episodes was fatal. The rate of thrombotic recurrences was 9.1 cases per 100 patient-years (95% CI, 3.3-19.6). Most recurrences took place in the same vascular bed as the original thrombosis. Age, time receiving anticoagulant therapy, primary vs secondary antiphospholipid syndrome, positivity for anticardiolipin antibodies, positivity for lupus anticoagulant, previous arterial thrombosis, previous stroke, previous venous thrombosis, and previous thrombocytopenia were not predictive of bleeding events. However, the risk of thrombotic recurrences was independently higher in patients who were receiving anticoagulation for longer periods.


CONCLUSIONS
The risk of intracranial and fatal bleeding in patients with definite antiphospholipid syndrome and previous thrombosis treated with oral anticoagulation to a target international normalized ratio of 3.5 is similar than in groups of patients treated to lower target ratios. The risk of thrombotic recurrences, even during anticoagulation, was high. Most recurrences took place in the same territory as original thromboses.
30359398
A retrospective review of 61 patients with antiphospholipid syndrome. Analysis of factors influencing recurrent thrombosis.
BACKGROUND
Antiphospholipid syndrome (APS) is a disorder of recurrent venous or arterial thrombosis, pregnancy losses, and thrombocytopenia. Recurrent thrombosis has particularly adverse effects on patients prognosis. The factors that influence recurrence and management techniques that prevent these events remain controversial. To add further insight regarding predisposing factors and the prevention of thrombotic recurrence, 61 well-characterized patients with APS were followed up for a median time of 77 months.


METHODS
A retrospective cohort study was conducted in which the following factors were examined to determine their influence on thrombotic recurrence: primary vs secondary syndrome; the presence of hypertension, hyperlipidemia, diabetes, or smoking; patient age, sex, and race; pregnancy and oral contraceptives use; and treatment with warfarin sodium, warfarin plus aspirin, aspirin alone, prednisone, or no treatment.


RESULTS
There was no difference between patients with primary and secondary APS with respect to recurrent arterial (55% vs 38%, respectively) or recurrent venous (47% vs 50%, respectively) thrombotic events. In all patients with APS, white race (P = .02) was associated with recurrent arterial events. Venous thrombosis occurred during pregnancy or in the postpartum period in 16 (30%) of 53 women and in 8 women taking oral contraceptives. Recurrent arterial and venous thromboses were significantly decreased with prophylactic warfarin use when compared with prednisone use or no treatment. Recurrences were infrequent in patients with prothrombin ratios of 1.5 to 2.0.


CONCLUSIONS
Treatment with warfarin was most effective in preventing recurrent arterial and venous thrombosis. Pregnancy and the use of oral contraceptives or prednisone may also influence recurrence.
38296875
Clinical manifestations and outcomes of antithrombotic treatment of the Tan Tock Seng Hospital Singapore antiphospholipid syndrome cohort
To examine the clinical manifestations, intensity of oral anticoagulation and outcomes in the prevention of recurrent thromboses in patients with antiphospholipid syndrome (APS) in a tertiary rheumatology centre in Singapore. Retrospective case review of consecutive patients with APS attending a rheumatology clinic from 1st January 2004 to 31st December 2005. There were 59 (44%) patients with definite APS and 75 (56%) with probable APS. Systemic lupus erythematosus (SLE) was the most common cause of secondary APS. Hypertension and hyperlipidaemia were the most common cardiovascular comorbidities. The most common manifestations were haematological (thrombocytopaenia and haemolytic anaemia), neurological (seizure, headache) and pulmonary hypertension. Among those with definite APS, there were similar proportions with arterial and venous thromboses. Recurrent thromboses occurred in 14 (23.7%) patient with definite APS receiving warfarin, comprising 14 (73.7%) episodes of arterial and 5 (26.3%) episodes of venous thromboses. Recurrent arterial thromboses occurred at international normalized ratio (INR) of <2 in 5 (35.7%), INR 2–3 in 6 (42.9%), INR > 3 in 3 (21.4%) episodes, respectively. Recurrent venous thromboses occurred at INR < 2 in 4 (80.0%) and INR > 3 in 1 (20.0%) episode, respectively. Twenty-eight episodes of bleeding occurred in 21 (35.6%) patients, the majority (78.6%) being minor bleeding. Two-thirds of all major bleeds occurred at INR ≥ 3. Venous and arterial thromboses were equally common in our patients with definite APS, although recurrent thromboses were more common in the arterial circulation. Target INR > 3 was associated with lower rates of recurrent arterial thromboses but higher rates of major and recurrent bleeding. Target INR ≥ 2 appeared to be sufficient to prevent recurrent venous thromboses.
39812605
Antiphospholipid antibodies predict imminent vascular events independently from other risk factors in a prospective cohort.
Antiphospholipid antibodies (aPL) are associated with vascular events, but the magnitude of this risk, alone, or in combination with other atherogenic and thrombophilic risk factors, remains unclear. A prospective cohort of 415 persons was studied for arterial and venous events (AE and VE) over a median time of 7.4 years. aPL and coagulation abnormalities were measured upon beginning of the study and annually for the first four years. Within the cohort, a nested case-control study was conducted to investigate the role of endothelial and inflammatory markers in predicting new vascular events. Forty-five individuals had new vascular events: 18 occurred during the first year of follow-up. The proportion of event-free survivors at eight years was 90% (95%CI = 87%, 94%) for aPL-negative and 72% (60%, 85%) for aPL-positive individuals, respectively. Predictors for new AE were previous AE (HR = 5.7 [2.7, 12.0]), diabetes (5.6 [2.4, 13.2]), aPL positivity (2.6 ([1.2, 5.9]), and age (1.04 [1.01, 1.07]). New VE were predicted by previous VE (6.1 [1.9, 19.9]), anti-beta2-glycoprotein I (abeta2GPI) positivity (5.8 [1.4, 24.1]), activated protein C resistance (APCR) (4.1 [1.1, 15.1]), and gender (3.7 [1.1, 12.9]). In the nested case-control study, similar predictors were observed for AE, while abnormal APCR (OR = 5.5 [1.1, 26.6]) and elevated von Willebrand factor (vWF) (OR = 5.0 [1.2, 19.8]) best predicted VE. We demonstrate that aPL independently predict new vascular events and discriminate between individuals with and without events in the first two years of follow-up, indicating that aPL are associated with a short-term risk of developing new and recurrent vascular events.
22438039
Clinical course of high‐risk patients diagnosed with antiphospholipid syndrome
See also Galli M. The antiphospholipid triangle. This issue, pp 234–6.
25386065
A comparison of two intensities of warfarin for the prevention of recurrent thrombosis in patients with the antiphospholipid antibody syndrome.
BACKGROUND
Many patients with the antiphospholipid antibody syndrome and recurrent thrombosis receive doses of warfarin adjusted to achieve an international normalized ratio (INR) of more than 3.0. However, there are no prospective data to support this approach to thromboprophylaxis.


METHODS
We performed a randomized, double-blind trial in which patients with antiphospholipid antibodies and previous thrombosis were assigned to receive enough warfarin to achieve an INR of 2.0 to 3.0 (moderate intensity) or 3.1 to 4.0 (high intensity). Our objective was to show that high-intensity warfarin was more effective in preventing thrombosis than moderate-intensity warfarin.


RESULTS
A total of 114 patients were enrolled in the study and followed for a mean of 2.7 years. Recurrent thrombosis occurred in 6 of 56 patients (10.7 percent) assigned to receive high-intensity warfarin and in 2 of 58 patients (3.4 percent) assigned to receive moderate-intensity warfarin (hazard ratio for the high-intensity group, 3.1; 95 percent confidence interval, 0.6 to 15.0). Major bleeding occurred in three patients assigned to receive high-intensity warfarin and four patients assigned to receive moderate-intensity warfarin (hazard ratio, 1.0; 95 percent confidence interval, 0.2 to 4.8).


CONCLUSIONS
High-intensity warfarin was not superior to moderate-intensity warfarin for thromboprophylaxis in patients with antiphospholipid antibodies and previous thrombosis. The low rate of recurrent thrombosis among patients in whom the target INR was 2.0 to 3.0 suggests that moderate-intensity warfarin is appropriate for patients with the antiphospholipid antibody syndrome.
34501597
A randomized clinical trial of high‐intensity warfarin vs. conventional antithrombotic therapy for the prevention of recurrent thrombosis in patients with the antiphospholipid syndrome (WAPS) 1
Summary.  Background: The optimal intensity of oral anticoagulation for the prevention of recurrent thrombosis in patients with antiphospholipid antibody syndrome is uncertain. Retrospective studies show that only high‐intensity oral anticoagulation [target international normalized ratio (INR) >3.0] is effective but a recent randomized clinical trial comparing high (INR range 3.0–4.0) vs. moderate (INR 2.0–3.0) intensities of anticoagulation failed to confirm this assumption. Methods: We conducted a randomized trial in which 109 patients with antiphospholipid syndrome (APS) and previous thrombosis were given either high‐intensity warfarin (INR range 3.0–4.5, 54 patients) or standard antithrombotic therapy (warfarin, INR range 2.0–3.0 in 52 patients or aspirin alone, 100 mg day−1 in three patients) to determine whether intensive anticoagulation is superior to standard treatment in preventing symptomatic thromboembolism without increasing the bleeding risk. Results: The 109 patients enrolled in the trial were followed up for a median time of 3.6 years. Mean INR during follow‐up was 3.2 (SD 0.6) in the high‐intensity warfarin group and 2.5 (SD 0.3) (P < 0.0001) in the conventional treatment patients given warfarin. Recurrent thrombosis was observed in six of 54 patients (11.1%) assigned to receive high‐intensity warfarin and in three of 55 patients (5.5%) assigned to receive conventional treatment [hazard ratio for the high intensity group, 1.97; 95% confidence interval (CI) 0.49–7.89]. Major and minor bleeding occurred in 15 patients (two major) (27.8%) assigned to receive high‐intensity warfarin and eight (three major) (14.6%) assigned to receive conventional treatment (hazard ratio 2.18; 95% CI 0.92–5.15). Conclusions: High‐intensity warfarin was not superior to standard treatment in preventing recurrent thrombosis in patients with APS and was associated with an increased rate of minor hemorrhagic complications.
42996573
A systematic review of secondary thromboprophylaxis in patients with antiphospholipid antibodies.
OBJECTIVE
To systematically review the efficacy and safety data of different therapeutic approaches in patients with antiphospholipid antibodies (aPL) and thrombosis.


METHODS
The Medline database and references from selected reports and review articles were used. Randomized controlled trials, prospective and retrospective cohort studies, and subgroup analysis (n > 15) that focused on the secondary thromboprophylaxis in patients with aPL were selected.


RESULTS
Sixteen studies were selected. Patients with venous events and a single test for aPL showed a low recurrence rate while receiving oral anticoagulation at a target international normalized ratio (INR) of 2.0-3.0. Patients with stroke and a single positive aPL test had no increased risk compared with those without aPL. Recurrence rates in patients with definite antiphospholipid syndrome (APS) and previous venous thromboembolism were lower than in patients with arterial and/or recurrent events, both with and without therapy. Only 3.8% of recurrent events occurred at an actual INR >3.0. Mortality due to recurrent thrombosis was higher than mortality due to bleeding (18 patients versus 1 patient reported).


CONCLUSION
For patients with definite APS, we recommend prolonged warfarin therapy at a target INR of 2.0-3.0 in APS patients with first venous events and >3.0 for those with recurrent and/or arterial events. For patients with venous thromboembolism or stroke and a single positive aPL test, we recommend further testing to determine if they have a persisting antibody. If they do not, the same therapy as for the general population should be used (warfarin at a target INR of 2.0-3.0 and low-dose aspirin, respectively).
24977996
Evidence-based recommendations for the prevention and long-term management of thrombosis in antiphospholipid antibody-positive patients: Report of a Task Force at the 13th International Congress on Antiphospholipid Antibodies
The antiphospholipid syndrome (APS) is defined by the presence of thrombosis and/or pregnancy morbidity in combination with the persistent presence of circulating antiphospholipid antibodies: lupus anticoagulant, anticardiolipin antibodies and/or anti-β2-glycoprotein I antibodies in medium to high titers. The management of thrombosis in patients with APS is a subject of controversy. This set of recommendations is the result of an effort to produce guidelines for therapy within a group of specialist physicians in Cardiology, Neurology, Hematology, Rheumatology and Internal Medicine, with a clinical and research focus on APS.
35226980
Antithrombotic treatment failures in antiphospholipid syndrome: the new anticoagulants?
Anticoagulation with oral vitamin K antagonists (VKA) is the mainstay of the treatment of venous and/or arterial thromboembolism in patients with antiphospholipid syndrome (APS), although the optimal intensity of anticoagulation remains controversial. The limitations of existing anticoagulants have driven a search for novel agents. Dabigatran etexilate (Pradaxa®), a direct thrombin inhibitor (DTI), and rivaroxaban (Xarelto®), the first in a new class of drugs, the oral direct factor Xa (FXa) inhibitors, are both fixed-dose orally administered agents. They are now licensed in the UK and Europe for the prevention of venous thromboembolism (VTE) in adult patients undergoing elective total hip replacement (THR) or total knee replacement (TKR). Prospective randomized clinical trials suggest that these agents, and also apixaban, a further oral direct anti-Xa inhibitor, may have potential in other areas including the treatment of acute VTE, prevention of stroke or systemic embolism in patients with atrial fibrillation (AF) and acute coronary syndromes. Here, we summarize current indications for these agents and address the potential for their use in patients with thrombotic APS.
6260123
Heparin inhibits the binding of beta 2-glycoprotein I to phospholipids and promotes the plasmin-mediated inactivation of this blood protein. Elucidation of the consequences of the two biological events in patients with the anti-phospholipid syndrome.
The phospholipid-binding plasma protein beta2-glycoprotein I (beta2-GPI) is the primary antigen recognized by the circulating autoantibodies in patients with the "anti-phospholipid syndrome" (APS). Although heparin is routinely used in the treatment and prophylaxis of APS patients, the primary heparin-binding site within beta2-GPI has not been identified. More importantly, how heparin exerts its beneficial effects in vivo in APS patients has not been deduced at the molecular level. Using an expression/site-directed mutagenesis approach, we now show that the positively charged site that resides in the first domain of beta2-GPI is not the primary heparin-binding site. Rather it is the second positively charged site located within the fifth domain of the protein that also binds to phospholipids. Lys(284), Lys(286), and Lys(287) in this domain are essential for the interaction of beta2-GPI with heparin. These data indicate that beta2-GPI binds to heparin in a relatively specific manner even though the affinity for the interaction is rather low. Lys(317) resides in the center of the high affinity phospholipid-binding site. Surprisingly, heparin at concentrations that can be achieved in vivo during anticoagulation therapy greatly enhances the plasmin-mediated cleavage of the Lys(317)-Thr(318) site in beta2-GPI. Because the cleaved form cannot bind to phospholipids effectively, the combined actions of heparin and plasmin result in a diminished ability of beta2-GPI to recognize phospholipids. This, in turn, decreases the prothrombotic activity of the endogenous circulating anti-beta2-GPI antibodies in the patients. Thus, heparin exerts its beneficial effects in APS patients by at least two distinct mechanisms.
3239562
Thrombotic recurrences and bleeding events in APS vascular patients: a review from the literature and a comparison with the APS Piedmont Cohort.
In APS vascular patients, thrombotic recurrences are more frequent than in non-APS thrombotic patients. To better define this clinical setting, a systematic review of the literature after 1999 was performed: 8 cohort studies (including the recent APS Piedmont Cohort) and 6 intervention studies were selected and evaluated. Thrombotic recurrences, bleeding events, therapeutic strategies, antiphospholipid (aPL) profile, inherited and acquired risk factors (when present) were calculated and compared. Emerging risk factors for thrombotic recurrences include withdrawal of oral anticoagulant therapy (OAT), high intensity OAT (INR range 3-4), aPL profile (triple positivity, Miyakis types 1 and 2a profiles) and association with inherited or acquired pro-thrombotic risk factors. Moreover, there are evidences that high risk (mainly for aPL profile) APS vascular patients have a high recurrence rate in spite of correct OAT treatment. Clinical trials in this clinical setting are needed.
24419314
Bleeding and re-thrombosis in primary antiphospholipid syndrome on oral anticoagulation: an 8-year longitudinal comparison with mitral valve replacement and inherited thrombophilia.
The aim of this study was to compare bleeding and re-thrombosis in primary antiphospholipid syndrome (PAPS), mitral valve replacement (MVR) and inherited thrombophilia (IT) at different oral anticoagulation intensities. It entailed a prospective 8-year follow-up on 67 patients with PAPS, 89 with IT and 24 with MVR. Anticardiolipin (aCL) antibodies detected by Elisa and lupus anticoagulant by clotting assays. At INR 2-3 minor bleeding rate was higher in MVR (33.3) than PAPS (10.9) and IT (4.2)(p<0.0001). At INR 3-4 minor bleeding rate was higher in PAPS (142) than IT (33.3) and MVR (5.8)(p<0.0001). At either INR major bleeding rate were not significantly different across the three groups, but in PAPS major and minor bleeding rates were superior at INR 3-4 than INR 2-3 (p=0.02 and p<0.0001). Re-thrombosis rate was higher in PAPS than IT at INR 2-3 (4.0 vs 0.35) (p=0.01) and at INR 3-4 (10.5 vs. nil). The hazard ratio for re-thrombosis between PAPS and IT was 13 (95% IC 1.6-102.2, p=0.015). By regression analysis, baseline IgG aCL titre (>80 GPL) p=0.001) and male sex (p=0.03) independently predicted re-thrombosis. In conclusion, in PAPS, high intensity oral anticoagulation was not superior to conventional intensity in preventing re-thrombosis but was offset by greater bleeding rates. Male sex and elevated baseline IgG aCL predicted rethrombosis in PAPS that is 13-fold more re-thrombogenic than IT.
422701
Antiphospholipid antibodies and venous thromboembolism.
The clinical relevance of antiphospholipid antibodies (APLA) in patients without systemic lupus erythematosus who have venous thromboembolism (VTE) in unknown. Limited evidence suggests that there is an association between the presence of APLA and both initial and recurrent episodes of VTE and that patients with APLA and VTE are resistant to warfarin therapy. Unselected patients with a first episode of clinically suspected deep vein thrombosis or pulmonary embolism were evaluated with objective tests for VTE and with laboratory tests for APLA; the latter included tests for the lupus anticoagulant (LA) and anticardiolipin antibodies (ACLA). Patients with VTE were treated with anticoagulant therapy and observed during and after discontinuation of anticoagulants for symptomatic recurrence of VTE. There was a strong association between LA and VTE (odds ratio, 9.4; 95% confidence interval [CI], 2.1 to 46.2) and 9 to 65 (14%; 95% CI, 7% to 25%) patients with VTE had LA. There was no association between the presence of ACLA and VTE (odds ratio, 0.7; 95%CI, 0.3 to 1.7) because of the high frequency of positive ACLA assays in patients without VTE. None of the 16 patients with VTE and APLA developed recurrent VTE while receiving warfarin therapy. There was no difference in rates of recurrent VTE in patients with or without APLA after anticoagulant therapy was discontinued. The strong association between LA and VTE suggests that testing for LA in patients with VTE is useful. The measurement of ACLA in patients with VTE has no clinical usefulness because the results are abnormal in a high proportion of patients without VTE. Although the presence of APLA in patients with VTE was not associated with resistance to a conventional intensity of warfarin or an increased risk of recurrent VTE after discontinuation of warfarin, a larger study should address these issues in a subgroup of patients with VTE and LA.
32635286
Antiphospholipid thrombosis: clinical course after the first thrombotic event in 70 patients.
OBJECTIVE
To determine the clinical course and influence of antithrombotic therapy in patients with lupus anticoagulant or anticardiolipin antibodies, or both, after the first thromboembolic event.


DESIGN
Retrospective survey of consecutive patients treated according to their physician's best judgment.


SETTING
Secondary and tertiary referral practice.


PATIENTS
Seventy patients (48 women [69%]) with a mean age (+/- SD) of 45.5 +/- 17.3 years. The antiphospholipid syndrome was primary in 51 patients (73%) and secondary to systemic lupus erythematosus in 14 patients (20%) and to chronic idiopathic thrombocytopenic purpura in 5 patients (7%).


MEASUREMENTS
Site of initial and recurrent thrombotic events (venous or arterial), as well as kind (aspiring, heparin, or warfarin) and intensity of anticoagulation.


RESULTS
Total follow-up after the first thrombotic event was 361.0 patient-years (mean [+/- SD], 5.2 +/- 5.6 years per patient). Thirty-seven patients (53%) had 54 recurrent events, with 2 patients experiencing fatal events. Arterial events were followed by arterial events, and venous events by venous events, in 49 of 54 instances (91%). Recurrence rates during "no treatment;" aspirin therapy; or low-, intermediate-, or high-intensity warfarin therapy (international normalized ratios [INRs] less than or equal to 1.9, 2.0 to 2.9, and greater than or equal to 3.0, respectively, or rabbit brain thromboplastin prothrombin time ratios of approximately less than 1.3, 1.3 to 1.5, and greater than 1.5, respectively) were 0.19, 0.32, 0.57, 0.07 (P = 0.12), and 0.00 (P less than 0.001) per patient-year. The follow-up periods for the five types of therapy were 161.2, 37.8, 11.3, 40.9, and 110.2 patient-years, respectively. The highest INR coincident with thrombosis was 2.6. Five warfarin-treated patients had five significant bleeding events (0.031 per patient-year).


CONCLUSIONS
Recurrent thrombosis is a potentially serious problem for patients with lupus anticoagulant or anticardiolipin antibodies or both. The site of the first event (arterial or venous) tended to predict the site of subsequent events. Intermediate- to high-intensity warfarin therapy may confer better antithrombotic protection than low- to intermediate-intensity warfarin therapy or aspirin therapy. Further studies are needed to define more precisely the rethrombosis rate and optimal type, intensity, and duration of antithrombotic therapy.
25171990
The management of thrombosis in the antiphospholipid-antibody syndrome.
BACKGROUND
The antiphospholipid-antibody syndrome is a thrombophilic disorder in which venous or arterial thrombosis, or both, may occur in patients with antiphospholipid antibodies. The optimal treatment of these patients is unclear. We assessed the efficacy of warfarin, low-dose aspirin, or both in the secondary prevention of thrombosis in patients with the syndrome.


METHODS
One hundred forty-seven patients (124 [84 percent] of whom were female) with the antiphospholipid-antibody syndrome and a history of thrombosis were studied retrospectively. The syndrome was primary in 62 patients and was associated with systemic lupus erythematosus in 66 patients and lupus-like disease in 19. Each patient's history was reviewed.


RESULTS
One hundred one patients (69 percent) had a total of 186 recurrences of thrombosis. The median time between the initial thrombosis and the first recurrence was 12 months (range, 0.5 to 144 months). Treatment with high-intensity warfarin (producing an international normalized ratio of > or = 3) with or without low-dose aspirin (75 mg per day) was significantly more effective (P < 0.001 by the log-rank test) than treatment with low-intensity warfarin (producing an international normalized ratio of < 3) with or without low-dose aspirin or treatment with aspirin alone in preventing further thrombotic events (recurrence rates per patient-year, 0.013, 0.23, and 0.18, respectively). The rate of recurrence of thrombosis was highest (1.30 per patient-year) during the first six months after the cessation of warfarin therapy. Complications involving bleeding occurred in 29 patients during warfarin therapy and were severe in 7 (0.071 and 0.017 occurrence per patient-year, respectively).


CONCLUSIONS
The risk of recurrent thrombosis in patients with the antiphospholipid-antibody syndrome is high. Long-term anticoagulation therapy in which the international normalized ratio is maintained at or above 3 is advisable in these patients.
6377341
Patients with antiphospholipid antibodies and venous thrombosis should receive long term anticoagulant treatment.
OBJECTIVE--To determine whether the finding of antiphospholipid antibodies in patients with venous thromboembolic episodes should influence the duration of treatment with anticoagulant drugs by mouth. METHODS--A retrospective study was carried out in 19 patients with antiphospholipid antibodies and a history of venous thromboembolic episodes. The median follow up from the first venous thromboembolic episode was 93 months and the median age at this episode was 26 years. The patients had in total 34 venous thromboembolic episodes. The total follow up period comprised 32 periods with and 23 periods without anticoagulant drugs. RESULTS--The probability of being free of recurrent venous thromboembolic episodes, calculated by the Kaplan-Meier method, was significantly influenced by the use of anticoagulant drugs. Patients receiving oral anticoagulants had at eight years a 100% probability of survival without recurrence, whereas patients in whom anticoagulant drugs were stopped had a 50% probability of a recurrent venous thromboembolic episode at two years, and a 78% probability of recurrence at eight years. CONCLUSION--Patients with venous thromboembolic episodes and antiphospholipid antibodies have a high risk for recurrent venous thromboembolic episodes and long term treatment with anticoagulant drugs by mouth is an effective prophylaxis.
31592384
Incidence of thromboembolism after stopping anticoagulant therapy. Relationship to hemorrhage at the time of termination.
Anticoagulant therapy was discontinued because of hemorrhage on 74 occasions and stopped electively on 166 others, and the incidence of subsequent thromboembolism in these two populations compared. Patients were placed in low-, intermediate-, or high-risk categories, depending on the presence or absence of factors previously shown to be associated with significant differences in the incidence. The proportion of patients in the "hemorrhage" and "elective" populations who fell into each category was similar and the two populations were comparable in other relevant respects. Comparison by means of a chi-square contingency analysis failed to show any significant differences in the relapse rates during any part of the 16-week follow-up period. Stopping anticoaguant therapy because of hemorrhage is not therefore associated with a risk of thromboembolism which is demonstrably greater than that observed after discontinuing treatment electively.
2787742
Discontinuation of anticoagulation or antiaggregation treatment may be safe in patients with primary antiphospholipid syndrome when antiphospholipid antibodies became persistently negative
Recommended treatment for patients with primary antiphospholipid syndrome (APS) after a thrombotic event is long-term anticoagulation. Few patients with APS and previously positive antiphospholipid antibodies (aPL) may become negative over time. It is still not exactly known how to treat these patients when aPL become persistently negative. We described the follow-up of 11 primary APS patients whose aPL become persistently negative and in whom thromboprophylaxis was discontinued. The primary end-point was the recurrence of thrombosis in patients with previous thrombotic event and a first thrombotic event in women with previous obstetric APS. Ten (90 %) patients were female. Seven (64 %) patients had a history of deep venous thrombosis, two of them with pulmonary embolism, and four (36 %) women had recurrent miscarriage. Lupus anticoagulant (LAC) was the aPL most frequently detected (82 %). Two patients had both LAC and IgG anticardiolipin antibodies. No new thrombotic episode was observed after a median follow-up period of 20 months. Anticoagulation or antiaggregation could be discontinued in some peculiar patients with low-risk primary APS whose aPL become persistently negative. However, studies including a larger number of patients are required to confirm these results.
38439327
[Anticoagulation treatment withdrawal in primary antiphospholipid syndrome when anticardiolipin antibodies become negative].
OBJECTIVES
The recommended treatment in patients with primary antiphospholipid syndrome (APS) after a thrombotic event is long-term anticoagulation. However, it is still not exactly known how to manage patients who remain stable for years and whose antiphospholipid antibodies (APA) decrease until becoming negative. This study aims to assess the course of the primary APS in a group of patients after anticoagulation therapy is discontinued.


PATIENTS AND METHOD
Ten patients with primary APS who had developed deep venous thrombosis in the limbs (9) or in the aorta (1) were included. After a minimum period of 12 months of anticoagulation therapy, this was discontinued if the patients were negative APA during the follow-up in two consecutive measurements.


RESULTS
Six patients (60%) developed persistent negative APA. Four had transient risk factors (2 pregnant, 1 immobilization, 2 oral contraceptives). No new thrombosis episode was observed after a follow-up period of 21 +/- 4.9 months.


CONCLUSIONS
Our data suggest that anticoagulation can be discontinued in those patients with primary APS and persistent negative APA, especially if the thrombotic event was venous and occurred in association with a transient risk factor, such as immobilization or pregnancy. Extensive studies are required to confirm these results.
4102130
Warfarin-related outcomes in patients with antiphospholipid antibody syndrome managed in an anticoagulation clinic.
Patients with antiphospholipid antibody syndrome (APA) are at elevated risk of venous and arterial thromboembolic complications. Oral anticoagulation with warfarin is recommended for secondary prevention of thromboembolism, but warfarin-related outcomes have not been systematically investigated when warfarin therapy is managed by a dedicated anticoagulation clinic. The objectives of the study were to evaluate warfarin-related monitoring outcomes, clinical endpoints and the use of healthcare resources as a result of warfarin-related complications in patients with APA compared to a group of patients without APA, all of whom were managed in an anticoagulation clinic setting. A retrospective observational cohort design was used to investigate patients with and without APA, all of whom had a history of venous or arterial thromboembolism, and were matched for age, gender and indication for oral anticoagulation. Thirty-six APA patients taking warfarin were compared to a matched cohort of 36 patients without APA. Monitoring outcomes (time in therapeutic range, clinic visits per year, frequency of warfarin dosing adjustments, reasons for out-of-range INRs) were similar between groups, as was the frequency of major bleeding complications (3.2%/pt-yr vs. 3.1%/pt-yr). However, recurrent thromboembolic events (9.6%/pt-yr vs 0) occurred more frequently in APA patients. APA patients required more emergency room visits (6.4%/pt-yr vs. 1.6%/pt-yr) and hospital admissions (14.4%/pt-yr vs.3.0%/pt-yr) to manage complications of warfarin therapy. In conclusion, despite similar monitoring outcomes obtained in a dedicated anticoagulation clinic setting, adverse clinical outcomes are significantly more frequent in patients with APA syndrome than in those without APA, and require more frequent use of healthcare resources.
41782186
Clinical study and follow-up of 100 patients with the antiphospholipid syndrome.
OBJECTIVES
To study the clinical characteristics at diagnosis and during follow-up of patients with the antiphospholipid syndrome (APS) and to analyze the influence of treatment on their outcome.


PATIENTS
One hundred patients with APS were included (86% female and 14% male; mean age, 36 years). Sixty-two percent had primary APS and 38% had APS associated with systemic lupus erythematosus (SLE). The median length of follow-up was 49 months.


RESULTS
Fifty-three percent of the patients had thromboses, 52% had thrombocytopenia, and 60% of the women had pregnancy losses. Patients with APS associated with SLE had a higher prevalence of hemolytic anemia (P = .02), thrombocytopenia (platelet count lower than 100 x 10(9)/L) (P = .004), antinuclear antibodies (P = .0002), and low complement levels. Fifty-three percent of the patients with thrombosis had recurrent episodes (86% in the same site as the previous thrombotic event). Recurrences were observed in 19% of the episodes treated with long-term oral anticoagulation, in 42% treated prophylactically with aspirin, and in 91% in which anticoagulant/antiaggregant treatment was discontinued (P = .0007). Multivariate analysis showed that prophylactic treatment and older age had an independent predictive value for rethrombosis. Prophylactic treatment during pregnancy (usually with aspirin) increased the live birth rate from 38% to 72% (P = .0002).


CONCLUSIONS
Patients with APS have a high risk of recurrent thromboses. Long-term oral anticoagulation seems to be the best prophylactic treatment to prevent recurrences. Prophylactic treatment with aspirin during pregnancy reduced the rate of miscarriages remarkably.
19391528
Antiphospholipid syndrome and asymptomatic carriers of antiphospholipid antibody: prospective analysis of 404 individuals.
OBJECTIVE
We carried out a prospective analysis of clinical and analytical findings in individuals with antiphospholipid antibodies (aPL).


METHODS
We prospectively studied 404 individuals, classified in 2 groups: (1) patients with primary or secondary antiphospholipid syndrome (APS, n = 226); and (2) asymptomatic carriers of aPL (n = 178). Patients with APS and thrombosis were treated with dicumarin, and an international normalized ratio around 3.0 (range 2.5-3.5) was targeted. Asymptomatic carriers were not treated, but specific prophylaxis with low molecular weight heparin or aspirin was prescribed for the periods when individuals were at increased risk of thrombosis. Both groups of individuals were followed up at semester intervals for 36 months.


RESULTS
Patients with APS presented with venous (n = 106, 46.9%) and/or arterial (n = 70. 31%) thrombosis or fetal loss (n = 58 out of 112 women of fertility age, 51.8%). At the time of the first thrombotic event, 50.0% of patients with APS had coincident risk factors for thrombosis (previous surgery and prolonged immobilization were significantly associated with venous thrombosis, and hypercholesterolemia and arterial hypertension with arterial thrombosis). Eighteen patients with APS died during the study period. Recurrence of thrombosis in patients with APS was linked to insufficient anticoagulation. During the followup, no episode of thrombosis was detected in any asymptomatic carrier. The proportion of subjects with aPL was similar in patients and in asymptomatic carriers. The proportion of subjects with aPL decreased during the followup, in both patients and carriers.


CONCLUSION
Differences between patients and asymptomatic carriers with aPL are at least partially dependent on the proportion of coincident vascular risk factors. The decline in aPL during the followup defines a subgroup in which an anticoagulation suppression assay could be tried.
18518925
Antiphospholipid antibodies and subsequent thrombo-occlusive events in patients with ischemic stroke.
CONTEXT
The presence of antiphospholipid antibodies (aPL) has been associated with vascular occlusive events. However, the role of aPL in predicting ischemic events, particularly recurrent ischemic stroke, is controversial.


OBJECTIVE
To evaluate the effect of baseline aPL positivity (ie, positivity for anticardiolipin antibodies [aCL], lupus anticoagulant antibodies [LA], or both) on subsequent thrombo-occlusive events, including recurrent stroke.


DESIGN, SETTING, AND PARTICIPANTS
The Antiphospholipid Antibodies and Stroke Study (APASS), a prospective cohort study within the Warfarin vs Aspirin Recurrent Stroke Study (WARSS), a randomized double-blind trial (N = 2206) conducted at multiple US clinical sites from June 1993 through June 2000 and comparing adjusted-dose warfarin (target international normalized ratio, 1.4-2.8) and aspirin (325 mg/d) for prevention of recurrent stroke or death. APASS participants were 1770 (80%) WARSS participants who consented to enroll in the APASS, with usable baseline blood samples drawn prior to randomization to the WARSS and analyzed for aPL status within 90 days of index stroke by a central independent laboratory. Quality assurance was performed on approximately 10% of samples by a second independent laboratory.


MAIN OUTCOME MEASURE
Two-year rate of the composite end point of death from any cause, ischemic stroke, transient ischemic attack, myocardial infarction, deep vein thrombosis, pulmonary embolism, and other systemic thrombo-occlusive events. The primary analysis assessed the outcome associated with aPL positivity within each WARSS treatment group separately, after risk-factor adjustment (since these aPL-positive vs aPL-negative comparisons were not randomized).


RESULTS
Of the 1770 APASS patients, 720 (41%) were classified as aPL-positive and 1050 (59%) as aPL-negative. There was no increased risk of thrombo-occlusive events associated with baseline aPL status in patients treated with either warfarin (relative risk [RR], 0.99; 95% confidence interval [CI], 0.75-1.31; P =.94), or aspirin (RR, 0.94; 95% CI, 0.70-1.28; P =.71). The overall event rate was 22.2% among aPL-positive and 21.8% among aPL-negative patients. There was no treatment x aPL interaction (P =.91). Patients with baseline positivity for both LA and aCL antibodies tended to have a higher event rate (31.7%) than did patients who tested negative for both antibodies (24.0%) (unadjusted RR, 1.36; 95% CI, 0.97-1.92; P =.07). Classification and regression tree analyses did not identify a specific LA test or aCL isotype or titer that was associated with increased risk of thrombo-occlusive event.


CONCLUSIONS
The presence of aPL (either LA or aCL) among patients with ischemic stroke does not predict either increased risk for subsequent vascular occlusive events over 2 years or a differential response to aspirin or warfarin therapy. Routine screening for aPL in patients with ischemic stroke does not appear warranted.
15852200
Comparison between single antiplatelet therapy and combination of antiplatelet and anticoagulation therapy for secondary prevention in ischemic stroke patients with antiphospholipid syndrome
Satisfactory results have not yet been obtained in therapy for secondary prevention in ischemic stroke patients with antiphospholipid syndrome (APS). We therefore compared single antiplatelet therapy and a combination of antiplatelet and anticoagulation therapy for secondary prevention in ischemic stroke patients with APS. The subjects were 20 ischemic stroke patients with antiphospholipid antibody, 13 with primary antiphospholipid syndrome and 7 with SLE-related antiphospholipid syndrome. Diagnosis of APS was based on the 2006 Sydney criteria. Eligible patients were randomly assigned to either single antiplatelet therapy (aspirin 100 mg) or a combination of antiplatelet and anticoagulation therapy (target INR: 2.0-3.0; mean 2.4±0.3) for the secondary prevention of stroke according to a double-blind protocol. There was no significant difference between the two groups in age, gender, NIH Stroke Scale on admission, mRS at discharge, or rate of hypertension, diabetes mellitus, hyperlipidemia, or cardiac disease. We obtained Kaplan-Meier survival curves for each treatment. The primary outcome was the occurrence of stroke. The mean follow-up time was 3.9±2.0 years. The cumulative incidence of stroke in patients with single antiplatelet treatment was statistically significantly higher than that in patients receiving the combination of antiplatelet and anticoagulation therapy (log-rank test, p-value=0.026). The incidence of hemorrhagic complications was similar in the two groups. The recent APASS study did not show any difference in effectiveness for secondary prevention between single antiplatelet (aspirin) and single anticoagulant (warfarin) therapy. Our results indicate that combination therapy may be more effective in APS-related ischemic stroke.
9505219
Mechanism of Endosomal TLR Inhibition by Antimalarial Drugs and Imidazoquinolines
Endosomal TLRs play an important role in innate immune response as well as in autoimmune processes. In the therapy of systemic lupus erythematosus, antimalarial drugs chloroquine, hydroxychloroquine, and quinacrine have been used for a long time. Their suppression of endosomal TLR activation has been attributed to the inhibition of endosomal acidification, which is a prerequisite for the activation of these receptors. We discovered that chloroquine inhibits only activation of endosomal TLRs by nucleic acids, whereas it augments activation of TLR8 by a small synthetic compound, R848. We detected direct binding of antimalarials to nucleic acids by spectroscopic experiments and determined their cellular colocalization. Further analysis revealed that other nucleic acid-binding compounds, such as propidium iodide, also inhibited activation of endosomal TLRs and colocalized with nucleic acids to endosomes. We found that imidazoquinolines, which are TLR7/8 agonists, inhibit TLR9 and TLR3 even in the absence of TLR7 or TLR8, and their mechanism of inhibition is similar to the antimalarials. In contrast to bafilomycin, none of the tested antimalarials and imidazoquinolines inhibited endosomal proteolysis or increased the endosomal pH, confirming that inhibition of pH acidification is not the underlying cause of inhibition. We conclude that the direct binding of inhibitors to nucleic acids mask their TLR-binding epitope and may explain the efficiency of those compounds in the treatment of autoimmune diseases.
22277768
Hydroxychloroquine reverses platelet activation induced by human IgG antiphospholipid antibodies.
Prothrombotic properties of antiphospholipid (aPL) antibodies may be explained in part by their ability to enhance the activation of platelets pre-treated with low doses of ADP or thrombin. The antimalarial drug hydroxychloroquine (HQ) has been used successfully in prevention of postoperative thrombosis and in treatment of patients with SLE or APS. In one study, administration of HQ reversed the thrombogenic properties of aPL in mice. However, the mechanism of action of HQ in preventing thrombosis is not clearly understood. In order to explore this further, the effects of HQ on activation of platelets by aPL in the presence of a thrombin agonist was studied. The changes in the expression of GPIIb/IIIa (CD41a) and GPIIIa (CD61) on platelet membrane by flow cytometry were used as indicators of platelet activation. Citrated whole blood from a healthy donor was treated at room temperature with suboptimal doses of a thrombin agonist receptor peptide (TRAP) and affinity-purified aPL antibodies, in the presence and in the absence of hydroxychloroquine (1 mM). TRAP increased the expression of GPIIb/IIIa and GPIIIa on platelet surface. The treatment of the platelets with the six aPL antibodies in the presence of 12 nMol/ml TRAP further increased the expression of GPIIb/IIIa by 42.3+/-12.3% and the expression of GPIIIa was further incremented by 46.8+/-13.5%. The effects of aPL and TRAP on expression of platelet surface markers of activation was completely abrogated by HQ in a dose-dependent fashion and was effective at concentrations of HQ as low as 25 microg/ml (0.0125 mM). This suggests at least one possible mechanism by which HQ may prevent thrombosis. This may have important implications in treatment of thrombosis in APS patients.
6908617
Hydroxychloroquine directly reduces the binding of antiphospholipid antibody-beta2-glycoprotein I complexes to phospholipid bilayers.
Treatment with the antimalarial drug hydroxychloroquine (HCQ) has been associated with reduced risk of thrombosis in the antiphospholipid (aPL) syndrome (APS) and, in an animal model of APS, with reduction of experimentally induced thrombosis. Recognition of beta2-glycoprotein I (beta2GPI) by aPL antibodies appears to play a major role in the disease process. We therefore used the techniques of ellipsometry and atomic force microscopy (AFM) to investigate whether HCQ directly affects the formation of aPL IgG-beta2GPI complexes on phospholipid bilayers. HCQ, at concentrations of 1 mug/mL and greater, significantly reduced the binding of aPL-beta2GPI complexes to phospholipid surfaces and THP-1 (human acute monocytic leukemia cell line) monocytes. The drug also reduced the binding of the individual proteins to bilayers. This HCQ-mediated reduction of binding was completely reversed when the HCQ-protein solutions were dialyzed against buffer. HCQ also caused modest, but statistically significant, reductions of clinical antiphospholipid assays. In conclusion, HCQ reduces the formation of aPL-beta2GPI complexes to phospholipid bilayers and cells. This effect appears to be due to reversible interactions between HCQ and the proteins and may contribute to the observed reduction of thrombosis in human and experimental APS. These results support the possibility that HCQ, or analogous molecules, may offer novel nonanticoagulant therapeutic strategies for treating APS.
2568583
Hydroxychloroquine protects the annexin A5 anticoagulant shield from disruption by antiphospholipid antibodies: evidence for a novel effect for an old antimalarial drug.
Annexin A5 (AnxA5) is a potent anticoagulant protein that crystallizes over phospholipid bilayers (PLBs), blocking their availability for coagulation reactions. Antiphospholipid antibodies disrupt AnxA5 binding, thereby accelerating coagulation reactions. This disruption may contribute to thrombosis and miscarriages in the antiphospholipid syndrome (APS). We investigated whether the antimalarial drug, hydroxychloroquine (HCQ), might affect this prothrombotic mechanism. Binding of AnxA5 to PLBs was measured with labeled AnxA5 and also imaged with atomic force microscopy. Immunoglobulin G levels, AnxA5, and plasma coagulation times were measured on cultured human umbilical vein endothelial cells and a syncytialized trophoblast cell line. AnxA5 anticoagulant activities of APS patient plasmas were also determined. HCQ reversed the effect of antiphospholipid antibodies on AnxA5 and restored AnxA5 binding to PLBs, an effect corroborated by atomic force microscopy. Similar reversals of antiphospholipid-induced abnormalities were measured on the surfaces of human umbilical vein endothelial cells and syncytialized trophoblast cell lines, wherein HCQ reduced the binding of antiphospholipid antibodies, increased cell-surface AnxA5 concentrations, and prolonged plasma coagulation to control levels. In addition, HCQ increased the AnxA5 anticoagulant activities of APS patient plasmas. In conclusion, HCQ reversed antiphospholipid-mediated disruptions of AnxA5 on PLBs and cultured cells, and in APS patient plasmas. These results support the concept of novel therapeutic approaches that address specific APS disease mechanisms.
41802761
Hydroxychloroquine reverses thrombogenic properties of antiphospholipid antibodies in mice.
BACKGROUND
Previous studies have demonstrated that human monoclonal and polyclonal anticardiolipin antibodies have thrombogenic properties in vivo. Using such a model in which these antibodies have been shown to increase both the size of an induced thrombus and the duration of time in which such a clot lasts, we investigated whether hydroxychloroquine alters the dynamics of such thrombus formation.


METHODS AND RESULTS
Three groups of nine mice were injected with purified immunoglobulin G (IgG) from a patient with the antiphospholipid syndrome (IgG-APS) and then fed with hydroxychloroquine at various doses (100, 6, and 3 mg/kg body wt). Three control groups of mice were also studied, including mice injected with IgG-APS and then fed with placebo, as well as two other groups injected with IgG from normal human serum and fed either hydroxychloroquine or placebo. A standardized thrombogenic injury was subsequently induced in the femoral vein of each mouse and the area (size) of thrombus measured as well as the total period of time that thrombus was present. Mice treated with hydroxychloroquine and IgG-APS showed significantly smaller thrombi that persisted for a shorter period of time compared with animals treated with IgG-APS and placebo.


CONCLUSIONS
Hydroxychloroquine significantly diminished both thrombus size and total time of thrombus formation in mice previously injected with IgG-APS.
32379021
Antithrombotic effects of hydroxychloroquine in primary antiphospholipid syndrome patients
T. Wu performed the experiments, analyzed the data, and contributed to the writing and editing of the manuscript; S. Yang and S. Haven performed the experiments and analyzed the data; V. M. Holers and A. S. Lundberg analyzed the data and contributed to the writing and editing of the manuscript; H. Wu performed the experiments, analyzed the data, and contributed to the writing and editing of the manuscript; and S. Cataland analyzed the data and contributed to the writing and editing of the manuscript.
11381927
14th International Congress on Antiphospholipid Antibodies: task force report on antiphospholipid syndrome treatment trends.
Antiphospholipid Syndrome (APS) is characterized by vascular thrombosis and/or pregnancy morbidity occurring in patients with persistent antiphospholipid antibodies (aPL). The primary objective of the APS Treatment Trends Task Force, created as part of the 14th International Congress on aPL, was to systematically review the potential future treatment strategies for aPL-positive patients. The task force chose as future clinical research directions: a) determining the necessity for controlled clinical trials in venous thromboembolism with the new oral direct thrombin or anti-factor Xa inhibitors pending the results of the ongoing rivaroxaban in APS (RAPS) trial, and designing controlled clinical trials in other forms of thrombotic APS; b) systematically analyzing the literature as well as aPL/APS registries, and creating specific registries for non-warfarin/heparin anticoagulants; c) increasing recruitment for an ongoing primary thrombosis prevention trial, and designing secondary thrombosis and pregnancy morbidity prevention trials with hydroxychloroquine; d) determining surrogate markers to select patients for statin trials; e) designing controlled studies with rituximab and other anti-B-cell agents; f) designing mechanistic and clinical studies with eculizumab and other complement inhibitors; and g) chemically modifying peptide therapy to improve the half-life and minimize immunogenicity. The report also includes recommendations for clinicians who consider using these agents in difficult-to-manage aPL-positive patients.
22715321
New oral anticoagulants in thrombotic antiphospholipid syndrome
A main goal in clinical management of patients with antiphospholipid syndrome (APS) is to prevent thrombotic recurrences and/or miscarriages. For many decades, the only available oral anticoagulant drugs have been vitamin K antagonists (VKA), which are still the cornerstone of long-term treatment of thromboembolism. However, the limits of VKA treatment are well known: narrow therapeutic window and high patient-to-patient variability of response. Moreover, in some patients with APS a higher international normalized ratio (INR) therapeutic target was suggested, and INR inaccuracy due to antiphospholipid antibodies was reported. Therefore, VKA management in APS patients is frequently cumbersome, requires close INR monitoring and may affect patient’s quality of life. A new class of oral anticoagulant agents has been developed, the Direct Oral Anticoagulants (DOA), which directly inhibit a single enzyme of the coagulation cascade. Compared with VKA, they have more stable pharmacokinetic and pharmacodynamic profiles, little interaction with food or drugs with a predictable anticoagulation effect, they can thus be prescribed in a fixed dose, without requiring frequent laboratory monitoring. The efficacy and safety of DOA has been shown in large phase III clinical trials. Unfortunately, translating these good results to APS patients is not straightforward: currently, at least three randomized controlled clinical trials are ongoing.
45551506
Safety and efficacy of oral direct inhibitors of thrombin and factor Xa in antiphospholipid syndrome.
BACKGROUND
Long-term anticoagulation is recommended in antiphospholipid syndrome with thrombosis in order to prevent recurrences. While the current mainstay relies on vitamin K antagonists, their long-term maintenance may remain challenging.


OBJECTIVES
To report on the safety and the efficacy of oral direct inhibitors of thrombin and factor Xa (ODIs) in antiphospholipid syndrome (APS).


METHODS
We performed a descriptive analysis of patients with APS enrolled in a French multicentre observational cohort between January 2012 and March 2014 and receiving ODIs. The main outcomes were the occurrence of a thrombotic recurrence or bleeding events.


RESULTS
Twenty-six patients with APS (primary in 12) received ODIs. Twenty patients had been previously treated with VKA (n=19), or fondaparinux (n=1) for a median duration of 3years. ODIs were introduced as second-line therapy because of INR lability/therapeutic simplification (n=17), recurrent thrombosis (n=1), VKA's associated bleeding event (n=1), and atrial fibrillation (n=1). Six patients received ODIs as first-line therapy. After a median [IQR] follow-up of 19 [8-29] months, one relapse of arterial thrombosis, two bleeding events (hypermenorrhea and rectal bleeding under rivaroxaban) and one recurrent migraine were reported, leading to discontinuation of therapy in these 4 patients.


CONCLUSION
ODIs might be an alternative therapeutic option in APS. Prospective studies are warranted to evaluate their safety in this condition.
22537018
Failure of dabigatran and rivaroxaban to prevent thromboembolism in antiphospholipid syndrome: a case series of three patients.
Direct oral factor inhibitors (DOFIs) are an attractive alternative to vitamin K antagonists (VKA) for the treatment of patients with antiphospholipid syndrome (APS). In the absence of prospective, randomised trial data, reports of therapeutic failures in clinical practice alert clinicians to potential limitations of DOFI therapy for this indication. Data for all cases were collected from a centralised system that contains complete medical records of all patients treated and followed at Mayo Medical Center. We present here three consecutive APS patients who had had no thromboembolism recurrence on warfarin but were switched to DOFIs. The diagnosis of APS was established according to currently recommended criteria. The three cases were as follows: A woman with primary APS developed thrombotic endocarditis with symptomatic cerebral emboli after transition to dabigatran. A second woman with primary APS experienced ischemic arterial strokes and right transverse-sigmoid sinus thrombosis after conversion to rivaroxaban. A man with secondary APS suffered porto-mesenteric venous thrombosis after switching to rivaroxaban. None of these patients had failed warfarin prior to the transition to DOFIs. Based on these three cases, we advocate caution in using DOFIs for APS patients outside of a clinical trial setting, until further data becomes available.
205773518
Prevalence of metabolic syndrome in primary antiphospholipid syndrome patients.
OBJECTIVE
To estimate the prevalence of metabolic syndrome (MetS) in patients with primary antiphospholipid syndrome (PAPS).


PATIENTS AND METHODS
Cross sectional study of PAPS patients from the outpatient clinic. MetS was based on three international definitions: World Health Organization (WHO), Adult Treatment Panel III (ATP III), or International Diabetes Federation (IDF). Clinical history and laboratory investigations, including insulin levels, lipid profile, glucose, and CRP, anthropometric and blood pressure measurements, were evaluated. Descriptive statistics was used. Kappa statistics examined the agreement between MetS definitions.


RESULTS
58 PAPS patients were studied, mean age 42.14±11.62, 9 men, 49 women. The most frequent cardiovascular risk (CVR) factors were hypertriglyceridemia, low HDL cholesterol levels, and visceral obesity. Prevalence of MetS was 17.2% according to WHO, 34.5% according to ATP III and 37.9% according to IDF criteria. MetS according to ATP III and WHO criteria was similar to the general population (34.5% vs. 36.8%) (17.2% vs. 13.6%), and lower according to IDF definition (37.9% vs. 49.8%).


CONCLUSIONS
This study shows a high prevalence of MetS in PAPS patients, similar to that in the general population and other autoimmune diseases. Identification of MetS is very important to indicate preventive strategies and reduce cardiovascular morbidity and mortality in PAPS.
25894548
Statins prevent endothelial cell activation induced by antiphospholipid (anti-beta2-glycoprotein I) antibodies: effect on the proadhesive and proinflammatory phenotype.
OBJECTIVE
To investigate the ability of statins, the inhibitors of the hydroxymethylglutaryl-coenzyme A reductase enzyme, to affect endothelial cell activation induced by anti-beta2-glycoprotein I (anti-beta2GPI) antibodies in vitro.


METHODS
Human umbilical vein endothelial cell (HUVEC) activation was evaluated as U937 monocyte adhesion, E-selectin, and intercellular adhesion molecule I (ICAM-1) expression by cell enzyme-linked immunosorbent assay and as interleukin-6 (IL-6) messenger RNA (mRNA) expression by RNA protection assay. E-selectin-specific nuclear factor kappaB (NF-kappaB) DNA-binding activity was evaluated by the gel-shift assay. HUVECs were activated by polyclonal affinity-purified IgG, human monoclonal IgM anti-beta2GPI antibodies, human recombinant IL-1beta, tumor necrosis factor alpha, or lipopolysaccharide (LPS).


RESULTS
Fluvastatin reduced, in a concentration-dependent manner (1-10 microM), the adhesion of U937 to HUVECs and the expression of E-selectin and ICAM-1 induced by anti-beta2GPI antibodies as well as by cytokines or LPS. Another lipophilic statin, simvastatin, displayed similar effects but to a lesser extent than fluvastatin. The inhibition of E-selectin expression exerted by fluvastatin was related to the impairment of NF-kappaB binding to DNA. Moreover, the drug attenuated the expression of IL-6 mRNA in HUVEC exposed to anti-beta2GPI antibodies or cytokines. Incubation of HUVECs with mevalonate (100 microM), concomitantly with fluvastatin, greatly prevented the inhibitory effect of statin.


CONCLUSION
Endothelial activation mediated by anti-beta2GPI antibody can be inhibited by statins. Because of the suggested role of endothelial cell activation in the pathogenesis of antiphospholipid syndrome (APS), our data provide, for the first time, a rationale for using statins as an additional therapeutic tool in APS.
25704693
Vitamin D: an instrumental factor in the anti-phospholipid syndrome by inhibition of tissue factor expression
Background and aims Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterised by thrombosis, obstetric complications and the presence of anti-phospholipid antibodies such as anti-β2GPI-Abs. These antibodies may set off the coagulation cascade via several mechanisms, including the induction of tissue factor (TF) expression. Vitamin D has recently emerged as an immunomodulator that might exert an anti-thrombotic effect. Therefore, we studied serum vitamin D levels in a cohort of APS patients, as well as the effect of vitamin D in an in vitro model of APS-mediated thrombosis. Methods Serum vitamin D levels were measured in 179 European APS patients and 141 healthy controls using the LIAISON chemiluminescent immunoassay, and the levels were evaluated in conjunction with a wide spectrum of clinical manifestations. In an vitro model, anti-β2GPI antibodies were purified from four patients with APS to evaluate the expression of TF in activated starved human umbilical vein endothelial cells. The effect of vitamin D (1,25-dihydroxyvitamin D, 10 nm) on anti-β2GPI-Abs mediated TF expression was analysed by immunoblot. Results Vitamin D deficiency (serum level ≤15 ng/ml) was documented in 49.5% of our APS patients versus 30% of controls (p<0.001) and was significantly correlated with thrombosis (58% vs 42%; p<0.05), neurological and ophthalmic manifestations, pulmonary hypertension, livedo reticularis and skin ulcerations. In vitro vitamin D inhibited the expression of TF induced by anti-β2GPI-antibodies. Conclusions Vitamin D deficiency is common among APS patients and is associated with clinically defined thrombotic events. Vitamin D inhibits anti-β2GPI-mediated TF expression in vitro. Thus, vitamin D deficiency might be associated with decreased inhibition of TF expression and increased coagulation in APS. Evaluation of vitamin D status and vitamin D supplementation in APS patients should be considered.
22856982
Low levels of vitamin D are common in primary antiphospholipid syndrome with thrombotic disease.
The aim of this study was to assess vitamin D (vit.D) levels in patients with primary antiphospholipid syndrome (PAPS), the association between hypovitaminosis D and clinical manifestations, and the effect of vit.D supplementation on serum levels. Vit.D serum levels of 115 PAPS patients, classified according to the 2006 revised criteria at the Rheumatology Department, Brescia, and of 128 voluntary healthy donors (NHD) were tested in collaboration with DiaSorin (Saluggia, Italy) using the LIAISON chemiluminescent immunoassay. Clinical data were derived from clinical charts. Vit.D deficiency was more prevalent in PAPS than NHD (17% vs 5%). During the summer, vit.D levels were lower in PAPS than NHD (median 28 vs 40.1 ng/mL, P<0.01). PAPS were subdivided according to clinical characteristics (thrombotic vs obstetric). Both groups had lower vit.D levels compared to NHD. Thrombotic PAPS had significantly lower levels than obstetric PAPS (median 20.8 vs 33.3, P<0.01). Sixteen patients (14%) received oral 25-OH vit.D supplementation (average 400 UI/die), but 63% of them did not reach serum levels above 30 ng/mL. PAPS showed significantly lower levels of vit.D than NHD. Hypovitaminosis D was seen to cluster in patients with thrombosis which may suggest that the lack of vit.D could be one of the many factors involved in the thrombotic process. Low-dose supplementation did not seem to be effective in a small group of patients.
12162812
Primary antiphospholipid syndrome in premenopausal women: low vitamin D, high fat mass and maintained bone mineral mass
The aim of this study was to analyze vitamin D levels and their association with bone mineral density and body composition in primary antiphospholipid syndrome. For this cross-sectional study 23 premenopausal women with primary antiphospholipid syndrome (Sapporo criteria) and 23 age- and race-matched healthy controls were enrolled. Demographic, anthropometric, clinical and laboratorial data were collected using clinical interview and chart review. Serum 25-hydroxyvitamin D levels, parathormone, calcium and 24-hour urinary calcium were evaluated in all subjects. Bone mineral density and body composition were studied by dual X-ray absorptiometry. The mean age of patients and controls was 33 years. Weight (75.61 [20.73] vs. 63.14 [7.34] kg, p = 0.009), body mass index (29.57 [7.17] vs. 25.35 [3.37] kg, p = 0.014) and caloric ingestion (2493 [1005.6] vs. 1990 [384.1] kcal/day, p = 0.03) were higher in PAPS than controls. All PAPS were under oral anticoagulant with INR within therapeutic range. Interestingly, biochemical bone parameters revealed lower levels of 25-hydroxyvitamin D [21.64 (11.26) vs. 28.59 (10.67) mg/dl, p = 0.039], serum calcium [9.04 (0.46) vs. 9.3 (0.46) mg/dl, p = 0.013] and 24-hour urinary calcium [106.55 (83.71) vs. 172.92 (119.05) mg/d, p = 0.027] in patients than in controls. Supporting these findings, parathormone levels were higher in primary antiphospholipid syndrome than in controls [64.82 (37.83) vs. 44.53 (19.62) pg/ml, p = 0.028]. The analysis of osteoporosis risk factors revealed that the two groups were comparable (p > 0.05). Lumbar spine, femoral neck, total femur and whole body bone mineral density were similar in both groups (p > 0.05). Higher fat mass [28.51 (12.93) vs. 20.01 (4.68) kg, p = 0.005] and higher percentage of fat [36.08 (7.37) vs. 31.23 (4.64)%, p = 0.010] were observed in PAPS in comparison with controls; although no difference was seen regarding lean mass. In summary, low vitamin D in primary antiphospholipid syndrome could be secondary to higher weight and fat mass herein observed most likely due to adipocyte sequestration. This weight gain may also justify the maintenance of bone mineral density even with altered biochemical bone parameters.
39458945
Vitamin D and antiphospholipid syndrome
Vitamin D (vitD) has been shown to have multiple immunomodulatory properties. Hypovitaminosis D has been described in many systemic autoimmune diseases. Antiphospholipid syndrome (APS), an autoimmune disease characterized by immune-mediated thrombosis and pregnancy loss, is a peculiar model for studying vitD, since these patients do not usually have a full-blown autoimmune disease, nor do they have particular restrictions regarding sun exposure. We assessed 25-OH vitD levels in 115 APS and 128 normal healthy donors (NHD) with the LIAISON® chemiluminescent immunoassay by DiaSorin (Italy). Median values were lower in APS patients than in NHD, with the greatest difference occurring during summertime (p < 0.01), suggesting that APS patients may be somehow prevented from vitD generation upon sun exposure. In our cohort, APS patients may have been instructed to use sunscreens in the presence of positive antinuclear antibodies (ANA). Comparing patients with positive and negative ANA, we found comparable vitD levels during the summer. By subdividing APS patients according to clinical features, thrombotic APS patients showed significantly lower levels than did pure obstetric APS patients (p < 0.01). In conclusion, our study confirms previous reports of hypovitaminosis D in APS patients, making them more similar to patients with other systemic autoimmune diseases than NHD. Hypovitaminosis D may be part of the mosaic of factors that determine autoimmunity, rather than a consequence of chronic disease and its treatment. The observation that patients with thrombotic APS, an aggressive phenotype, may be more deficient than those with exclusive obstetric manifestations fits well with the beneficial effects of vitD on thrombosis described both in vitro and in vivo. Therefore, there may be a rationale to assess the efficacy of vitD supplementation in APS patients.
23168948
Long-Term Outpatient Dalteparin (Fragmin) Therapy for Arterial and Venous Thrombosis: Efficacy and Safety—A Preliminary Report
The availability of low molecular weight heparin (LMWH), with associated ease of home delivery and enhanced efficacy and safety, has rendered the long-term outpatient use of LMWH feasible. Although warfarin is usually used for long-term secondary prevention, it is not the drug of choice for a variety of conditions such as antiphospholipid thrombosis syndrome, sticky platelet syndrome, and patients with malignancy and other medical conditions who have failed adequate warfarin doses. We assessed the long-term efficacy and safety of outpatient dalteparin in a series of patients with conditions associated with prior warfarin failure or potential to warfarin therapy (antiphospholipid syndrome). The results of this study, detailed herein, demonstrate that long-term dalteparin is highly effective and safe when used as long-term therapy for secondary prevention in selected prothrombotic disorders.
20976018
Low-molecular weight heparin: treatment failure in a patient with primary antiphospholipid antibody syndrome.
Antiphospholipid antibody syndrome is an acquired autoimmune disorder characterized by vascular thrombosis and/or recurrent pregnancy losses along with laboratory evidence of antiphospholipid antibodies. Anticoagulation rather than immunosuppression is the mainstay of treatment. Despite the effectiveness of oral anticoagulation for the prevention of recurrent thromboembolic episodes, thrombotic complications in the setting of apparently therapeutic oral anticoagulation have been observed; this may at times be due to difficulties in maintaining a consistently therapeutic level of anticoagulation. Low-molecular-weight heparin has been a useful alternative for long-term anticoagulation when there is difficulty in managing oral anticoagulant therapy and has the advantage of a consistent anticoagulant effect. In this report, we describe a woman with primary antiphospholipid antibody syndrome who developed extensive pulmonary embolism despite receiving a proven therapeutic dosage of low molecular weight heparin.
26921630
Long‐duration therapy with low molecular weight heparin in patients with antiphospholipid antibody syndrome resistant to warfarin therapy
contact with the fibers exhibited the discoid shape of resting platelets without any sign of granule centralization (Fig. 1A, right panel), thus confirming our previous report. In addition, we measured collagen-induced calcium signaling. To avoid artefactual rises in fluorescence because of aggregation, which are often observed with collagen as an agonist, a GPIIb/IIIa antagonist (abciximab) was added to the system. Under these conditions, 25 lg mL collagen induced an intracellular calcium rise of 394 ± 39 nM (Fig. 1B, left panel). In contrast, no calcium rise could be measured when platelets were stimulated by collagen in the combined presence of aspirin and MRS2179 (Fig. 1B, right panel). Altogether these results confirm and reinforce the observation that collagen is unable to induce measurable calcium increases and to promote platelet shape change when both the P2Y1 and the TXA2 pathways are blocked. Thus, the discrepancy between these results and those from Riondino et al. [4] cannot be explained by different microscopy procedures and failure to monitor calcium changes. Additional differences in the type of collagen or the washing procedure could be invoked. Several types of fibrillar collagens were used and resulted in essentially the same results (not shown). One would then favor the platelet washing procedure to explain these divergent observations. Reading carefully the research conducted by Riondino et al. [4], and especially the description of the method to isolate platelets, it does not seem that they use the cocktail of inhibitors that we use to prevent trace amounts of thrombin, leakage of ADP, and mechanical stress during centrifugation. Resolving this issue is not a minor point as the conclusions might have important pharmacologic implications. Indeed, as the secondary agonists seem to play such a major role during platelet activation by collagen, it would appear more advantageous to improve pharmacologic targeting of these pathways rather than the collagen receptors themselves. As such, although not yet under clinical evaluation, the P2Y1 receptor might be a promising target in combination with the cheapest antiplatelet drug aspirin.
206865179
Efficacy and safety of long-term low molecular weight heparin in patients with antiphospholipid syndrome
Objective Evaluation of the effectiveness and safety of long-term low molecular weight heparin (LMWH) in patients with antiphospholipid syndrome (APS) that had not previously responded to or tolerated oral vitamin K antagonists. Methods 23 patients with confirmed diagnosis of APS were retrospectively recruited. All patients were receiving LMWH as a result of intolerance and/or lack of response to warfarin therapy. The type of LMWH, the duration of treatment, the reason for switching to LMWH and the adverse effects were recorded. Outcomes were classified as no improvement, partial improvement or total improvement after at least 1 year of using LMWH. Results The average duration of LMWH treatment was 36 months. Most of the patients were on treatment with enoxaparin (n=16, 69%) and were switched to LMWH from warfarin mainly because of thrombosis despite therapeutic international normalised ratio (n=9, 39%). Good quality of life with no evidence of recurrent thrombotic events was noted in nine patients (39%), whereas 11 (48%) showed partial clinical improvement but no evidence of recurrent thrombotic episodes. Osteoporosis was reported in five patients (23%), all of whom were also receiving treatment with corticosteroids. Conclusions Long-term LMWH may be a safe and effective alternative to warfarin for APS patients.
19280602
Low-molecular-weight heparin versus a coumarin for the prevention of recurrent venous thromboembolism in patients with cancer.
BACKGROUND
Patients with cancer have a substantial risk of recurrent thrombosis despite the use of oral anticoagulant therapy. We compared the efficacy of a low-molecular-weight heparin with that of an oral anticoagulant agent in preventing recurrent thrombosis in patients with cancer.


METHODS
Patients with cancer who had acute, symptomatic proximal deep-vein thrombosis, pulmonary embolism, or both were randomly assigned to receive low-molecular-weight heparin (dalteparin) at a dose of 200 IU per kilogram of body weight subcutaneously once daily for five to seven days and a coumarin derivative for six months (target international normalized ratio, 2.5) or dalteparin alone for six months (200 IU per kilogram once daily for one month, followed by a daily dose of approximately 150 IU per kilogram for five months).


RESULTS
During the six-month study period, 27 of 336 patients in the dalteparin group had recurrent venous thromboembolism, as compared with 53 of 336 patients in the oral-anticoagulant group (hazard ratio, 0.48; P=0.002). The probability of recurrent thromboembolism at six months was 17 percent in the oral-anticoagulant group and 9 percent in the dalteparin group. No significant difference between the dalteparin group and the oral-anticoagulant group was detected in the rate of major bleeding (6 percent and 4 percent, respectively) or any bleeding (14 percent and 19 percent, respectively). The mortality rate at six months was 39 percent in the dalteparin group and 41 percent in the oral-anticoagulant group.


CONCLUSIONS
In patients with cancer and acute venous thromboembolism, dalteparin was more effective than an oral anticoagulant in reducing the risk of recurrent thromboembolism without increasing the risk of bleeding.
29002540
Intravenous immunoglobulin therapy in antiphospholipid syndrome
Antiphospholipid syndrome (APS) is an autoimmune disorder defined by the occurrence of venous and arterial thromboses and pregnancy morbidity, frequently accompanied by a moderate thrombocytopenia, in the presence of antiphospholipid antibodies. There is both laboratory and clinical evidence for the beneficial role of intravenous immunoglobulin (IVIg) in APS. Data on the use of IVIg in patients with APS have focused on its obstetric complications and antiphospholipid antibodies-positive patients undergoing in vitro fertilization, but there are also case reports about treatments of other clinical manifestations (mainly hematological) of the syndrome.Future research should determine when to use anticoagulation, IVIg, or both in the treatment of APS.
40650513
Identification of an Fc gamma receptor-independent mechanism by which intravenous immunoglobulin ameliorates antiphospholipid antibody-induced thrombogenic phenotype.
OBJECTIVE
Patients with the antiphospholipid antibody syndrome (APS) often experience recurrent arterial and venous thrombosis and pregnancy losses. Intravenous immunoglobulin (IVIG) therapy has prevented pregnancy loss in some women with APS and has reversed fetal resorption rates in murine models of pregnancy loss. Although the basis for these effects is unknown, effector mechanisms of pathogenic antibodies often involve receptors for IgG (Fc gamma receptors [Fc gammaR]). We examined the potential mechanisms of action of WIG in an in vivo murine model of antiphospholipid antibody (aPL)-induced thrombosis and endothelial cell activation.


METHODS
Mice infused with IgG containing human anticardiolipin antibodies (aCL) were treated with IVIG (36 microg i.v.), saline, or ovalbumin. Surgically induced thrombus formation and in vivo leukocyte adhesion to endothelial cells were measured. Circulating levels of aCL were measured by enzyme-linked immunosorbent assay. To determine whether Fc gammaR are required for the effects of IVIG, we treated mice deficient in stimulatory Fc gammaR. To examine the effects of IVIG on endogenously generated antibody, we treated mice immunized with beta2-glycoprotein I (beta2GPI).


RESULTS
IVIG treatment inhibited aPL-induced endothelial cell activation and enhancement of thrombosis in mice passively infused with human aPL-containing IgG, and this was associated with a decrease in aPL levels. Similarly, IVIG lowered aPL levels and inhibited thrombogenesis in mice immunized with beta2GPI. The thrombophilic effects of aPL were evident in Fc gammaR-deficient mice.


CONCLUSION
Treatment with IVIG inhibits the thrombogenic effects of aPL in vivo and reduces the levels of aCL in the circulation. Blockade of stimulatory Fc gammaR on inflammatory cells is not necessary for this effect. The mechanism of action of IVIG is more likely saturation of the IgG transport receptor, leading to accelerated catabolism of pathogenic aPL. These results have implications in the management of thrombosis in APS and may have applications for pregnant patients with a history of APS.
7919130
Intravenous immunoglobulin therapy of antiphospholipid syndrome.
OBJECTIVE
To review the role of intravenous immunoglobulin (IVIg) in antiphospholipid syndrome (APS).


METHODS
A literature search was carried out for the immunopathogenesis of APS, laboratory evidence for the beneficial effect of IVIg in APS, and the clinical use of IVIg in APS.


RESULTS
There is both laboratory and clinical evidence for the beneficial role of IVIg in APS. IVIg succeeded in in vitro inhibition of anticardiolipin antibodies and lupus anticoagulant, and in the amelioration of experimental APS. Although there are few case reports about IVIg therapy in the haematological manifestations of APS, most of the reports focus on the use of IVIg in the obstetric complications of APS. Hence, in several patient series the use of IVIg either solely or in combination with aspirin/heparin resulted in successful pregnancy outcome in the vast majority of APS patients with recurrent abortions. In addition, IVIg was also beneficial in antiphospholipid antibody-positive patients undergoing in vitro fertilization.


CONCLUSION
APS, an autoimmune disease whose main features are vascular thrombosis and pregnancy morbidity, is a good candidate for immunotherapy with IVIg that contains anti-idiotypes directed towards patients' pathogenic antiphospholipid antibodies. Future research should determine when to use anticoagulation, IVIg or both in the treatment of APS.
36665068
Long-term treatment of antiphospholipid syndrome with intravenous immunoglobulin in addition to conventional therapy.
OBJECTIVES
This work aims to prospectively assess the long-term effects of intravenous immunoglobulin (IVIG Flebogamma®) in a small cohort of patients affected by primary or secondary antiphospholipid syndrome (APS), in addition to conventional therapy.


METHODS
Three primary and four secondary APS patients (6 women and 1 man), aged between 40 and 62 years, were treated with IVIG in addition to conventional therapy with anticoagulants or antiplatelets, while six primary and one secondary APS patients (6 women and 1 man), aged between 31 and 61 years, continued their regular conventional therapy. One infusion of IVIG was administered at a dose of 0.4 g/kg/day every month to the first group of patients for two years. Patients were assessed at baseline, after 1 year and 2 years from the beginning of the study and were evaluated for the occurrence of any thromboembolic events and by laboratory measurement of antiphospholipides antibodies (aPL).


RESULTS
No venous or arterial thromboses occurred in patients treated with IVIG, whereas in the control group two patients presented cerebral ischaemic attacks and one patient reported a deep vein thrombosis during the follow-up. At the end of the study, in the group treated with IVIG, we observed a statistically significant decrease of anticardiolipin antibodies (IgG and IgM) and of IgM anti-β2-glycoprotein I antibodies.


CONCLUSIONS
Our results show the efficacy of IVIG in addition to conventional therapy, in primary and secondary APS patients, preventing the occurrence of thromboembolic events. However, further clinical studies on a larger group of patients are necessary to fully understand the mechanisms of action and the optimal doses of IVIG in APS.
25864308
Prevention of thrombosis relapse in antiphospholipid syndrome patients refractory to conventional therapy using intravenous immunoglobulin.
OBJECTIVES
To investigate the long-term effects of megadoses of intravenous immunoglobulin (IVIG) in a small cohort of patients with relapsing primary APS resistant to conventional treatments.


METHODS
Five primary APS patients, 4 women, mean age 45.1 years (range 31-76 years), were considered eligible for IVIG therapy due to relapsing thrombotic events (4 recurrent venous thromboses, 2 ischaemic cerebral strokes, 2 pulmonary thromboembolisms, 1 thrombotic event on the vena cava filter), despite conventional therapy with anticoagulants. All patients had anti-nuclear antibodies at low-medium titre without other signs or symptoms of systemic lupus erythematosus. IVIG was combined with hydroxychloroquine and, in patients with cerebral strokes, acetylsalicylic acid. Three consecutive daily infusions of IVIG were administered intravenously at a dose of 0.4 g/kg/day every month for 3 months, followed by a single monthly infusion for 9 months.


RESULTS
No further thromboses occurred in the 5 treated patients (mean follow-up 89.2 months, range 61-114). Visual analogue score (VAS 0-10) improved (mean 3.5, range 3.0-5.0, before, and 7.35, range 9.9-6.0, p= 0.05) after IVIG treatment.


CONCLUSIONS
In a long-term (>5 years) open study in a small cohort of high risk primary APS patients, IVIG was found to be effective in preventing recurrent thrombosis. Full understanding of the mechanisms and efficacy, as well as the optimal doses of IVIG in APS patients with recurrent thrombosis, will require appropriately designed clinical studies. Presently, IVIG use is restricted by costs and limited availability.
24858636
Prevention of murine antiphospholipid syndrome by BAFF blockade.
OBJECTIVE
This study was undertaken to determine whether BAFF blockade can be used to prevent or treat antiphospholipid syndrome in a mouse model.


METHODS
Eight- and 12-week-old (NZW x BXSB)F(1) mice were treated with BAFF-R-Ig or TACI-Ig alone or in addition to a short course of CTLA-4Ig. Mice were monitored for thrombocytopenia and proteinuria. Sera were tested for anticardiolipin antibodies (aCL), BAFF levels, and levels of soluble vascular cell adhesion molecule and E-selectin. Mice were killed at 17, 22, or 32 weeks of age, and kidneys and hearts were subjected to histologic examination. Spleen cells were phenotyped and enzyme-linked immunospot assays for autoantibody-producing B cells were performed.


RESULTS
Both BAFF-R-Ig and TACI-Ig prevented disease onset and significantly prolonged survival. Treated mice had significantly smaller spleens than controls, with fewer B cells and fewer activated and memory T cells. BAFF blockade did not prevent the development of aCL, and there was only a modest delay in the development of thrombocytopenia. However, treated mice had significantly less nephritis and myocardial infarcts than did controls.


CONCLUSION
Our findings suggest that aCL are generated in the germinal center, which is relatively independent of BAFF. Effector function of antiplatelet antibodies was only modestly affected by BAFF blockade. In contrast, myocardial infarctions were prevented, suggesting that triggering of thromboses requires both autoantibodies and mediators of inflammation. Similarly, renal damage requires both immune complexes and effector cells. The dissociation between autoantibody production and inflammation that may occur with B cell-depleting therapies underscores the role of B cells as effector cells in the autoimmune response.
44912900
CTLA4Ig Prevents Initiation but not Evolution of Anti-phospholipid Syndrome in NZW/BXSB Mice
NZW “×” BXSB F1 mice develop SLE that is associated with an anti-phospholipid syndrome characterized by anti-cardiolipin antibodies, thrombocytopenia and small coronary artery thrombosis. This syndrome is immune mediated and, dependent, on CD4+T cells. To determine whether disease in these mice can be treated with blockade of T cell costimulation we treated them with the CD28 antagonist CTLA4Ig at 9 or 12 weeks of age. CTLA4Ig completely prevented both SLE nephritis and myocardial infarcts if it was given at 9 weeks of age, before anti-cardiolipin antibodies could be detected in the serum and prevented both B cell expansion and activation and the development of peripheral monocytosis. If treatment was delayed until 12 weeks of age after cardiolipin antibodies had arisen but before the onset of clinical disease, CTLA4Ig had very little effect on disease progression. These findings indicate that CD4+T cell activation through CD28 is critical for disease initiation in this model but plays little role in disease progression or tissue damage. These findings have relevance to the treatment of anti-phospholipid syndrome in humans.
12419047
Belimumab reduces autoantibodies, normalizes low complement levels, and reduces select B cell populations in patients with systemic lupus erythematosus.
OBJECTIVE
To assess the effects of the B lymphocyte stimulator (BLyS)-specific inhibitor belimumab on immunologic biomarkers, including B cell and T cell populations, and maintenance of antibody titers to prior vaccines in autoantibody-positive systemic lupus erythematosus (SLE) patients.


METHODS
Pooled data from 2 phase III trials, the Study of Belimumab in Subjects with SLE 52-week (BLISS-52) and 76-week (BLISS-76) trials, comparing belimumab 1 mg/kg or 10 mg/kg versus placebo (plus standard SLE therapy for each group) were analyzed for changes in autoantibody, immunoglobulin, and complement levels. BLISS-76 patients were also analyzed for changes in B cell and T cell populations and effects on prior vaccine-induced antibody levels.


RESULTS
Belimumab-treated patients experienced significant sustained reductions in IgG and autoantibodies and improvement in C3/C4 levels, resulting in greater positive-to-negative conversion rates for IgG anti-double-stranded DNA (anti-dsDNA), anti-Sm, anticardiolipin, and anti-ribosomal P autoantibodies and normalization of hypergammaglobulinemia and low C3/C4 levels. Belimumab-treated patients experienced significant decreases in the numbers of naive and activated B cells, as well as plasma cells, whereas memory B cells and T cell populations did not decrease. Belimumab did not substantially affect preexisting antipneumococcal or anti-tetanus toxoid antibody levels. Post hoc analysis showed greater reductions in SLE disease activity and the risk of severe flares in patients treated with belimumab 10 mg/kg (P≤0.01) who were anti-dsDNA positive and had low C3/C4 levels at baseline. Normalization of the C3 or anti-dsDNA level by 8 weeks, irrespective of therapy, was predictive of a reduced risk of severe flare over 52 weeks.


CONCLUSION
Belimumab appears to promote normalization of serologic activity and reduce BLyS-dependent B cell subsets in serologically and clinically active SLE. Greater serologic activity may predict a better treatment response to belimumab.
44460871
A Systematic Review of the Off-Label Use of Biological Therapies in Systemic Autoimmune Diseases
In 2006, the Study Group on Autoimmune Diseases (GEAS) of the Spanish Society of Internal Medicine created the BIOGEAS project, a multicenter study devoted to collecting data on the use of biological agents in adult patients with systemic autoimmune diseases (SAD). The information source is a periodic surveillance of reported cases by a MEDLINE search (last update before this writing: December 31, 2007). The analysis included a total of 19 SAD and 6 biological agents. By December 31, 2007, the Registry included 1370 patients with SAD who had been treated with biological agents (562 received infliximab, 463 rituximab, 285 etanercept, 42 anakinra, and 18 adalimumab). SAD included Sjögren syndrome (SS; 215 cases), Wegener granulomatosis (261 cases), sarcoidosis (219 cases), systemic lupus erythematosus (SLE; 172 cases), Behçet disease (173 cases), adult-onset Still disease (118 cases), cryoglobulinemia (88 cases), and other diseases (80 cases). The higher rate of therapeutic response was found for the use of rituximab in patients with SLE (90%), SS (91%), antiphospholipid syndrome (92%), and cryoglobulinemia (87%); infliximab in sarcoidosis (99%), adult-onset Still disease (90%), and polychondritis (86%); and etanercept in Behçet disease (96%). Results from controlled trials showed lack of efficacy for the use of infliximab in SS and etanercept in SS, Wegener granulomatosis, and sarcoidosis. In addition, an excess of side effects (>50% of reported cases) was observed for the use of infliximab in inflammatory myopathies and sarcoidosis, and for the use of etanercept in polymyositis. Sufficient data are not yet available to evaluate fully the efficacy and safety of adalimumab and anakinra in patients with SAD. In conclusion, current scientific evidence on the use of biological therapies in patients with SAD is mainly based on uncontrolled, observational data. The best results have been observed in the use of rituximab for SS, SLE, and cryoglobulinemia; infliximab for sarcoidosis and adult-onset Still disease; and etanercept for Behçet disease. Lack of efficacy was demonstrated for infliximab and etanercept in SS, for etanercept in Wegener granulomatosis and sarcoidosis, and for anti-tumor necrosis factor (TNF) in SS. Future controlled trials are needed to confirm the potential use of biological therapies in patients with SAD. Abbreviation: ACCP = American College of Chest Physicians, AE = adverse event, EMEA = European Medicines Agency, FDA = United States Food and Drug Administration, FVC = forced vital capacity, GCA = giant cell arteritis, MPA = microscopic polyangiitis, PMR = polymyalgia rheumatica, RCTs = randomized controlled trials, SAD = systemic autoimmune diseases, SLE = systemic lupus erythematosus, SS = Sjögren syndrome, TNF = tumor necrosis factor, TR = therapeutic response, UCS = uncontrolled studies
235546
B-cell directed therapies in antiphospholipid antibody syndrome--new directions based on murine and human data.
The increased awareness of the role of humoral immunophysiology in antiphospholipid syndrome (APS) has aroused interest in B cells as therapeutic targets in this disease. This paper reviews the literature on B cell directed therapies in human and experimental APS. The clinical data is limited to B cell depletion with rituximab and comprises case reports and case series. Murine studies include use of modulators of B cell function such as belimumab and abatacept. In both human and murine studies, B cell directed therapies appeared to have clinical and serologic beneficial effects including a decrease in the antiphospholipid antibody titers after treatment. Randomized controlled clinical trials are needed to determine whether B cell depletors and/or B cell modulators can be effective agents for treating patients with APS.
205428380
A pilot open-label phase II trial of rituximab for non-criteria manifestations of antiphospholipid syndrome.
OBJECTIVE
The primary objective of this study was to evaluate the safety of rituximab in antiphospholipid antibody (aPL)-positive patients with non-criteria manifestations of antiphospholipid syndrome (APS). The secondary objectives were to evaluate the effect of rituximab on the aPL profile and to evaluate the efficacy of rituximab treatment for non-criteria manifestations of APS.


METHODS
In this 12-month, phase II pilot study, adult aPL-positive patients with thrombocytopenia, cardiac valve disease, skin ulcer, aPL nephropathy, and/or cognitive dysfunction received 2 doses of rituximab (1,000 mg) on days 1 and 15. Antiphospholipid antibody profiles and clinical outcome measures, which were categorized as complete response, partial response, no response, or recurrence, were analyzed at preset time points.


RESULTS
Two of 19 patients experienced infusion reactions, resulting in early termination. Twelve serious adverse events and 49 nonserious adverse events were recorded. All patients who had positive results of lupus anticoagulant, anticardiolipin, and anti-β(2)-glycoprotein I antibody tests at baseline had positive results at 24 weeks and 52 weeks. The numbers of patients with a complete response, a partial response, no response, and recurrence for the clinical outcome measures at 24 weeks were as follows: for thrombocytopenia, 1, 1, 2, and 0, respectively; for cardiac valve disease, 0, 0, 3, and not analyzed, respectively; for skin ulcer, 3, 1, 0, and 1, respectively; for aPL nephropathy, 0, 1, 0, and 0, respectively; and for cognitive dysfunction, 3, 1, 1, and not analyzed, respectively.


CONCLUSION
The results of this uncontrolled and nonrandomized pilot study suggest that the safety of rituximab in aPL-positive patients is consistent with the safety profile of rituximab. Despite causing no substantial change in aPL profiles, rituximab may be effective in controlling some but not all non-criteria manifestations of APS.
205303006
Severe acute thrombotic exacerbation in two cases with anti-phospholipid syndrome after retreatment with rituximab in phase I/II clinical trial for refractory systemic lupus erythematosus.
treatment of early oestrogen-receptor-positive breast cancer. 2006. 2 Smith IE, Dowsett M. Aromatase inhibitors in breast cancer. N Engl J Med 2003;348:2431–42. 3 Body JJ, Bergmann P, Boonen S et al. Management of cancer treatment-induced bone loss in early breast and prostate cancer – a consensus paper of the Belgian Bone Club. Osteoporos Int 2007;18:1439–50. 4 McCloskey E. Effects of third-generation aromatase inhibitors on bone. Eur J Cancer 2006;42:1044–51. 5 Hillner BE, Ingle JN, Chlebowski RT et al. American Society of Clinical Oncology 2003 update on the role of bisphosphonates and bone health issues in women with breast cancer. J Clin Oncol 2003;21:4042–57. 6 Reid DM et al.; UK Expert Group. The 12th Conference on Osteoporosis. National Osteoporosis Society, 2007.
25040678
Mortality in the catastrophic antiphospholipid syndrome: causes of death and prognostic factors in a series of 250 patients.
OBJECTIVE
To assess the main causes of death and the prognostic factors that influence mortality in patients with the catastrophic antiphospholipid syndrome (CAPS).


METHODS
We analyzed the case reports of 250 patients included in the CAPS Registry up to February 2005. To identify prognostic factors for CAPS, we compared the main clinical and immunologic features and the types of treatment in the patients who died with those features in the patients who survived.


RESULTS
Recovery occurred in 56% of the episodes of CAPS and death occurred in 44%. Cerebral involvement, consisting mainly of stroke, cerebral hemorrhage, and encephalopathy, was considered the main cause of death, being present in 27.2% of patients, followed by cardiac involvement (19.8%) and infection (19.8%). The only factor we identified that was prognostic of a higher mortality rate was the presence of systemic lupus erythematosus (SLE). A higher recovery rate was associated with combined treatment with anticoagulants (ACs) plus corticosteroids (CS) plus plasma exchange (PE) (77.8%), followed by ACs plus CS plus PE and/or intravenous immunoglobulins (69%). In contrast, concomitant treatment with cyclophosphamide did not demonstrate additional benefit.


CONCLUSION
Cerebral involvement (mainly consisting of stroke), cardiac involvement, and infections were considered the main causes of death in patients with CAPS. The presence of SLE was related to a higher mortality rate. According to the results of the present study, ACs plus CS plus PE should be the first line of therapy in patients with CAPS.
25966981
Therapeutic plasma exchange for the management of refractory systemic autoimmune diseases: report of 31 cases and review of the literature.
INTRODUCTION
Therapeutic plasma exchange (TPE) represents a treatment option in patients with systemic autoimmune diseases because most of their clinical manifestations are related to the presence of antibodies or immune complex deposition.


OBJECTIVE
To describe the main demographic and clinical characteristics as well as the outcome of patients with systemic autoimmune diseases treated with TPE at a tertiary care center.


METHODS
We included all patients with systemic autoimmune diseases in whom the indication for treatment with TPE was a flare of the disease between 1999 and 2010. The indications for treatment, complications and outcomes were obtained from review of medical records.


RESULTS
A total of 31 patients (18 (58%) females and 13 (42%) males) were treated with a total of 196 TPE sessions with an average of 6.3 sessions per patient. Mean age at the time of TPE was 52.9 years (range, 26.0-82.0 years). Ten (32.3%) patients had ANCA-associated vasculitides, 6 (19.4%) mixed cryoglobulinemia secondary to hepatitis C virus (HCV) infection, 5 (16.1%) essential mixed cryoglobulinemia, 4 (12.9%) catastrophic antiphospholipid syndrome, 3 (9.7%) systemic lupus erythematosus, 2(6.5%) dermatomyositis and 1 (3.1%) polyarteritis nodosa. All patients except one were receiving corticosteroids at varying doses and all received a concomitant immunosuppressive drug. Ten (32.3%) and 9 (29.0%) patients received rituximab and intravenous immunoglobulins prior to TPE, respectively. Six patients experienced catheter-related infections, 5 urinary infections and 3 patients developed hospital acquired pneumonia. Eleven patients died in spite of the TPE.


CONCLUSIONS
TPE is an effective therapeutic option for treating serious manifestations of systemic autoimmune diseases and a valid option for those patients with refractory disease to conventional treatments.
205775088
Rituximab use in the catastrophic antiphospholipid syndrome: descriptive analysis of the CAPS registry patients receiving rituximab.
The catastrophic variant of the antiphospholipid syndrome (APS) is characterized by thrombosis in multiple organs developing over a short period of time. First-line treatment for the catastrophic APS is the combination of anticoagulation plus corticosteroids plus plasma exchange and/or intravenous immunoglobulin. Despite this regimen, the mortality remains high and new treatment options are needed. By a systematic review of the Catastrophic APS Registry (CAPS Registry), we identified 20 patients treated with rituximab. The purpose of this study is to describe the clinical manifestations, laboratory features, and outcomes of rituximab-treated CAPS patients. In addition, the rationale for using rituximab in catastrophic APS is discussed.
24132585
C5a induces tissue factor activity on endothelial cells.
Tissue factor (TF) is an integral membrane glycoprotein that serves as a cofactor for blood coagulation factor VIIa. The induction of TF on the surface of endothelial cells is initiated by various stimuli including lipopolysaccharide, interleukin-1 beta, and tumor necrosis factor alpha. We have demonstrated that recombinant human C5a induces TF activity in a dose-dependent fashion in human umbilical vein endothelial cells (HUVEC). Peak activity (4.9-fold increase) was obtained 3-6 h after treatment with 10 microM C5a. TF mRNA as assessed by RT-PCR method was also significantly increased (3.75-fold) after 3 h incubation with C5a, suggesting that C5a induces TF activity on HUVEC, at least in part, by enhancing the level of TF mRNA. The increase in TF activity by C5a was inhibited by methylprednisolone. The induction of TF on endothelial cells by C5a may represent one of many potential interrelationships between the inflammatory and coagulation schemes.
35711382
A Novel C5a Receptor-Tissue Factor Cross-Talk in Neutrophils Links Innate Immunity to Coagulation Pathways1
Neutrophils and complement are key sentinels of innate immunity and mediators of acute inflammation. Recent studies have suggested that inflammatory processes modulate thrombogenic pathways. To date, the potential cross-talk between innate immunity and thrombosis and the precise molecular pathway by which complement and neutrophils trigger the coagulation process have remained elusive. In this study, we demonstrate that antiphospholipid Ab-induced complement activation and downstream signaling via C5a receptors in neutrophils leads to the induction of tissue factor (TF), a key initiating component of the blood coagulation cascade. TF expression by neutrophils was associated with an enhanced procoagulant activity, as verified by a modified prothrombin time assay inhibited by anti-TF mAb. Inhibition studies using the complement inhibitor compstatin revealed that complement activation is triggered by antiphospholipid syndrome (APS) IgG and leads to the induction of a TF-dependent coagulant activity. Blockade studies using a selective C5a receptor antagonist and stimulation of neutrophils with recombinant human C5a demonstrated that C5a, and its receptor C5aR, mediate the expression of TF in neutrophils and thereby significantly enhance the procoagulant activity of neutrophils exposed to APS serum. These results identify a novel cross-talk between the complement and coagulation cascades that can potentially be exploited therapeutically in the treatment of APS and other complement-associated thrombotic diseases.
26989917
Treatment of atypical hemolytic uremic syndrome and thrombotic microangiopathies: a focus on eculizumab.
Uncontrolled complement activation is central to the occurrence of atypical hemolytic uremic syndrome (aHUS) and can result in thrombotic microangiopathies (TMAs). These terms encompass a group of heterogenic inherited or acquired diseases that recent research suggests may be triggered by the complement cascade. Pathogenetic triggers of complement activation include immunologic disorders, genetics, infections, systemic diseases, pregnancy, drug administration, metabolic diseases, transplantation, or triggers of mixed cause. Hallmarks of aHUS and other TMAs include increased vascular endothelium thromboresistance, leukocyte adhesion to damaged endothelium, complement consumption, coagulation abnormalities, and vascular shear stress, whereas common end points of these mechanisms include hemolytic anemia, thrombocytopenia with microvascular infarction, and predisposition for decreased kidney function and other organ involvement. The central role of the complement cascade as a disease trigger suggests a possible therapeutic target. Eculizumab, a first-in-class humanized monoclonal anti-C5 antibody that has been successful in the treatment of paroxysmal nocturnal hemoglobinuria, a disorder of complement-induced hemolytic anemia, received approval for the treatment of aHUS in the United States and Europe in late 2011. We review the treatment of aHUS and other TMAs, focusing on the role of eculizumab, including its pharmacology, mechanism of action, and approved dosing recommendations and health economic considerations. Finally, the potential for future indications for eculizumab use in other complement-driven diseases is discussed.
330775
Eculizumab and renal transplantation in a patient with CAPS.
To the Editor: The catastrophic antiphospholipid antibody syndrome (CAPS) is an episodic, diffuse thrombotic microangiopathy observed in less than 1% of patients with antiphospholipid antibodies and is characterized by vascular occlusions involving three or more organ systems.1 Typically preceded by triggering events, such as infection, trauma, or surgery, CAPS culminates in multiorgan system failure and is fatal in half of those in whom it develops. Although renal failure is common in CAPS survivors, kidney transplantation has traditionally not been considered in these patients because of the lack of specific therapies for preventing recurrent CAPS and a surgical risk of death . . .
8255798
Brief report: induction of sustained remission in recurrent catastrophic antiphospholipid syndrome via inhibition of terminal complement with eculizumab.
OBJECTIVE
Catastrophic antiphospholipid syndrome (CAPS) is characterized by histopathologic evidence of small vessel thrombosis, dysfunction of multiple organs occurring over a short period of time, and laboratory confirmation of the presence of antiphospholipid antibodies (aPL). Treatment of CAPS focuses on anticoagulation therapy and on removal of aPL that promote thrombosis by activating endothelial cells, monocytes, and platelets. Studies in animal models support the hypothesis that a more targeted intervention, such as complement inhibition, may be an effective means to prevent aPL-induced thrombosis. Herein we describe use of an inhibitor of complement activation to treat CAPS that was refractory to conventional therapy.


METHODS
Our patient was a young man who had recurrent CAPS characterized by multiple arterial thromboses in large and small vessels despite maximal anticoagulation, immunosuppression, and plasma exchange therapy. We treated him with eculizumab, an anti-C5 monoclonal antibody that blocks activation of terminal complement.


RESULTS
Administration of eculizumab, at doses that blocked complement activity, aborted acute progressive thrombotic events, reversed thrombocytopenia, and was associated with no further clinical episodes of thrombosis during >3 years of therapy.


CONCLUSION
This first report of the use and clinical efficacy of eculizumab, an inhibitor of complement activation, in the treatment of CAPS demonstrates both the importance of complement (specifically, terminal complement components) in the pathogenesis of CAPS and the therapeutic benefit of complement inactivation.
20248732
Eculizumab Improves Posttransplant Thrombotic Microangiopathy Due to Antiphospholipid Syndrome Recurrence but Fails to Prevent Chronic Vascular Changes
Thrombotic microangiopathy (TMA) is one of the hallmark vascular lesions of antiphospholipid syndrome nephropathy (APSN). These lesions are at high risk of recurrence after kidney transplantation. The complement pathway is thought to be active in this process. We used eculizumab to treat three consecutive kidney transplant recipients with posttransplant TMA due to APSN recurrence that was resistant to plasmapheresis and explored the complement deposition and apoptotic and vascular cell markers on the sequential transplant biopsies. Treatment with eculizumab resulted in a rapid and dramatic improvement of the graft function in all three patients and in improvement of the TMA lesions within the graft. None of these patients had TMA flares after eculizumab was withdrawn. At the time of TMA diagnosis, immunofluorescence studies revealed intense C5b‐9 and C4d depositions at the endothelial cell surface of the injured vessels. Moreover, C5b‐9 colocalized with vessels exhibiting a high rate of apoptotic cells. Examination of sequential biopsies during eculizumab therapy showed that TMA lesions, C4d and apoptotic markers were rapidly cleared but the C5b‐9 deposits persisted for several months as a footprint of the TMA. Finally, we noticed that complement inhibition did not prevent the development of the chronic vascular changes associated with APSN. Eculizumab seems to be an efficient method for treating severe forms of posttransplant TMA due to APSN recurrence. Terminal complement inhibition does not prevent the development of chronic APSN.
206993087
Eculizumab Prevents Recurrent Antiphospholipid Antibody Syndrome and Enables Successful Renal Transplantation
Renal transplantation in patients with antiphospholipid antibodies has historically proven challenging due to increased risk for thrombosis and allograft failure. This is especially true for patients with antiphospholipid antibody syndrome (APS) and its rare subtype, the catastrophic antiphospholipid antibody syndrome (CAPS). Since a critical mechanism of thrombosis in APS/CAPS is one mediated by complement activation, we hypothesized that preemptive treatment with the terminal complement inhibitor, eculizumab, would reduce the extent of vascular injury and thrombosis, enabling renal transplantation for patients in whom it would otherwise be contraindicated. Three patients with APS, two with a history of CAPS, were treated with continuous systemic anticoagulation together with eculizumab prior to and following live donor renal transplantation. Two patients were also sensitized to human leukocyte antigens (HLA) and required plasmapheresis for reduction of donor‐specific antibodies. After follow‐up ranging from 4 months to 4 years, all patients have functioning renal allografts. No systemic thrombotic events or early graft losses were observed. While the appropriate duration of treatment remains to be determined, this case series suggests that complement inhibitors such as eculizumab may prove to be effective in preventing the recurrence of APS after renal transplantation.
44720078
Insights into defibrotide: an updated review
Defibrotide is a polydisperse oligonucleotide with antiatherosclerotic, anti-inflammatory, anti-ischaemic, pro-fibrinolytic and antithrombotic actions without significant systemic anticoagulant effects. It has been used in the treatment of various cardiovascular disorders, and especially in endothelial complications of allogeneic stem-cell transplantation. We reviewed the published work for the mechanism of action and clinical use of defibrotide to consolidate data and to describe new applications of this drug. We reviewed the most relevant papers on defibrotide published from November 1982 to January 2008. (selected through PubMed), and used recent meeting abstracts as sources for this review. Reports have suggested that defibrotide has clinical efficacy for treatment and prophylaxis of hepatic sinusoidal obstruction syndrome occurring after stem-cell transplantation. Animal models have clearly shown the potential antineoplastic effect of this drug. Further clinical investigations are needed to clarify this new application.
2223691
Defibrotide reduces procoagulant activity and increases fibrinolytic properties of endothelial cells
Defibrotide (DF), a polydeoxyribonucleotide with antithrombotic properties, has recently proven effective in patients with severe hepatic veno-occlusive disease (VOD), a life-threatening complication of high-dose chemo/radiotherapy regimens for stem cell transplantation. To understand the mechanism of its beneficial effect, we studied the impact of DF on the expression of tissue factor (TF) and fibrinolytic proteins (PAI-1 and t-PA) on endothelial cells. The in vitro response to DF of two types of human endothelial cells (ECs) of different origins, that is from macrovascular (HUVEC) and microvascular (HMEC-1 cell line) beds, was evaluated in the presence or absence of a proinflammatory stimulus (ie bacterial endotoxin, LPS). The results show that DF was able to significantly reduce the LPS-induced TF expression by HMEC-1, and less prominently by HUVEC. In addition, DF importantly influenced the fibrinolytic properties of both HMEC-1 and HUVEC. Specifically, it dose-dependently counteracted the LPS-induced increase in PAI-1 levels and decrease in t-PA activity expression. It also significantly incremented t-PA antigen in resting EC. Decreasing the procoagulant activity and increasing the fibrinolytic potential of EC favors an anticoagulant phenotype of the endothelium, which may protect from fibrin deposition and vascular occlusion.
38987794
Catastrophic Antiphospholipid Syndrome: Clues to the Pathogenesis from a Series of 80 Patients
The antiphospholipid syndrome (APS), originally defined as the combination of venous or arterial thrombotic events, recurrent fetal loss, and, frequently, a moderate thrombocytopenia in association with antiphospholipid antibodies (aPL), was subsequently greatly expanded to include diverse conditions, for example, heart valve lesions, adrenal insufficiency, and pulmonary syndromes such as acute respiratory distress syndrome (ARDS), “capillaritis,” and pulmonary alveolar hemorrhage, among others (16, 17). It was then realized that several “microangiopathic syndromes” also existed, as opposed to large vessel occlusive disease. Single organs, such as the kidneys, heart, skin, and brain, have been affected by this “thrombotic microangiopathy” in the context of the “classic” or “simple” APS. The temporal occurrence of thrombotic events in patients with this classic APS usually extends over months or years. In 1992, the existence of a new “subset” was described in which multiple vascular occlusive events, usually affecting small vessels supplying organs and presenting over a short period of time, were the outstanding features. This subset was termed the “catastrophic” APS. Although large vessel occlusions were also present, their prevalence did not in any way approach that in patients with the classic APS. The occlusions occurred over days to several weeks, and more than 50% of patients usually succumbed despite seemingly adequate therapy, including anticoagulation, steroids, etc. (6). In 1998, a comprehensive review article with the clinical and laboratory description of 50 such patients was published (8). In the present paper we describe the clinical and serologic features of the largest series of patients with catastrophic APS hitherto reported, including 30 new cases from interested physicians in many different countries, as well as a comprehensive literature review of 50 additional recently published case reports with this syndrome. This new series, comprising a total of 80 patients, enables us to analyze further and clarify not only the clinical importance of this syndrome, but also its pathogenesis. 0025-7974/01/8006-0355/0 MEDICINE® 80: 355-77, 2001 Vol. 80, No. 6 Copyright © 2001 by Lippincott Williams & Wilkins, Inc. Printed in U.S.A.
24207218
Treatment of catastrophic antiphospholipid syndrome with defibrotide, a proposed vascular endothelial cell modulator.
OBJECTIVE
To define at the molecular level the vascular endothelial cell (VEC) injury characteristics of catastrophic antiphospholipid syndrome (CAPS) and to report successful therapeutic use of a VEC modulator, defibrotide.


METHODS
We describe a 55-year-old man with primary APS with an intractable prothrombotic state (CAPS) resistant to combined therapy with heparin, warfarin, aspirin, and dipyridamole. Treatment with defibrotide was conducted in the context of an investigational phase II protocol where the dose was regulated and individualized by disease/patient-specific molecular and clinical markers.


RESULTS
The patient entered complete remission with defibrotide treatment. During treatment, dose dependent pharmacological actions of defibrotide and key stress markers for VEC injury were identified. Evidence of defibrotide's polypharmacology included downregulation of cytokines, notably tumor necrosis factor-alpha, as the earliest effect, cellular differentiation of VEC, possibly with direct regulatory effect over cellular genes, and the reversal of platelet consumption and prothrombotic state. Von Willebrand antigen levels were used as the sole marker to guide therapy.


CONCLUSION
This case demonstrates effective remission of CAPS with defibrotide treatment. In contrast to theories that CAPS is triggered by ischemic and thrombotic tissue damage, these data present VEC injury as the primary and representative lesion of CAPS. The pathogenesis may involve concurrent impairment of different VEC functions. Achieving remission may require a polypharmacologic approach, represented here by use of defibrotide.
23321053
Efficacy of aspirin for the primary prevention of thrombosis in patients with antiphospholipid antibodies: an international and collaborative meta-analysis.
We performed a meta-analysis to determine whether aspirin has a significant protective effect on risk of first thrombosis among patients with antiphospholipid antibodies (aPL+). Observational and interventional studies identified from the Medline, Embase and Cochrane databases were selected if they assessed the incidence of first thrombosis in aPL+ patients treated with aspirin versus those without. Pooled effect estimates were obtained using a random-effects model. Of 1211 citation retrieved, 11 primary studies (10 observational and 1 interventional) met inclusion criteria, including a total of 1208 patients and 139 thrombotic events. The pooled odds ratio (OR) for the risk of first thrombosis in patients treated with aspirin (n=601) was 0.50 (95%CI: 0.27 to 0.93) compared to those without aspirin (n=607), with significant heterogeneity across studies (I(2)=46%, p=0.05). Subgroup analysis showed a protective effect of aspirin against arterial (OR: 0.48 [95%CI: 0.28-0.82]) but not venous (OR: 0.58 [95% CI: 0.32-1.06]) thrombosis, as well as in retrospective (OR: 0.23 [0.13-0.42]) but not prospective studies (OR: 0.91 [0.52-1.59]). Subgroup analysis according to underlying disease revealed a significant protective effect of aspirin for asymptomatic aPL+ individuals (OR: 0.50 [0.25-0.99]), for systemic lupus erythematosus (SLE) (OR: 0.55 [0.31-0.98]) and obstetrical antiphospholipid syndrome (APS) (OR: 0.25 [0.10-0.62]). This meta-analysis shows that the risk of first thrombotic event is significantly decreased by low dose aspirin among asymptomatic aPL individuals, patients with SLE or obstetrical APS. Importantly, no significant risk reduction was observed when considering only prospective studies or those with the best methodological quality.
46263440
Aspirin for primary thrombosis prevention in the antiphospholipid syndrome: a randomized, double-blind, placebo-controlled trial in asymptomatic antiphospholipid antibody-positive individuals.
OBJECTIVE
To determine the efficacy of a daily dose of 81 mg aspirin in primary thrombosis prevention in asymptomatic, persistently antiphospholipid antibody (aPL)-positive individuals (those with positive aPL but no vascular and/or pregnancy events).


METHODS
The Antiphospholipid Antibody Acetylsalicylic Acid (APLASA) study was a multicenter, randomized, double-blind, placebo-controlled clinical trial in which asymptomatic, persistently aPL-positive individuals were randomized to receive a daily dose of 81 mg of aspirin or placebo. In a separate observational and parallel study, asymptomatic, persistently aPL-positive individuals who were taking aspirin or declined randomization were followed up prospectively.


RESULTS
In the APLASA study, 98 individuals were randomized to receive aspirin or placebo (mean +/- SD followup period 2.30 +/- 0.95 years), of whom 48 received aspirin and 50 received placebo. In the observational study, 74 nonrandomized individuals were followed up prospectively (mean +/- SD followup period 2.46 +/- 0.76 years); 61 received aspirin and 13 did not. In the APLASA study, the acute thrombosis incidence rates were 2.75 per 100 patient-years for aspirin-treated subjects and 0 per 100 patient-years for the placebo-treated subjects (hazard ratio 1.04, 95% confidence interval 0.69-1.56) (P = 0.83). Similarly, in the observational study, the acute thrombosis incidence rates were 2.70 per 100 patient-years for aspirin-treated subjects and 0 per 100 patient-years for those not treated with aspirin. All but 1 patient with thrombosis in either study had concomitant thrombosis risk factors and/or systemic autoimmune disease at the time of thrombosis.


CONCLUSION
Our results suggest that asymptomatic, persistently aPL-positive individuals do not benefit from low-dose aspirin for primary thrombosis prophylaxis, have a low overall annual incidence rate of acute thrombosis, and develop vascular events when additional thrombosis risk factors are present.
20175807
Potential effect of anti-inflammatory treatment on reducing the cardiovascular risk in rheumatoid arthritis.
Rheumatoid arthritis (RA) is a chronic inflammatory polyarthritis with increased mortality largely attributable to cardiovascular disease. There is extensive evidence that patients with RA experience accelerated atherosclerosis, which is considered as the main responsible of this increased cardiovascular burden. Nowadays atherosclerosis is regarded as an inflammatory condition: hence, the cumulative inflammation of RA, with the abundant synthesis of proinflammatory cytokines, contributes directly to the early formation of the atheromatic plaque. It is therefore reasonable to postulate that, by alleviating inflammation, drugs commonly used in RA treatment may ameliorate the cardiovascular profile of these patients. Here we provide an extensive review of the literature, focusing on the effects of the available anti-rheumatic agents on cardiovascular mortality, and morbidity among RA sufferers.
44720373
Antiphospholipid antibody profiles and their clinical associations in Chinese patients with systemic lupus erythematosus.
OBJECTIVE
Different prevalences of antiphospholipid antibodies (aPL) have been reported in different populations of patients with systemic lupus erythematosus (SLE). Chinese are generally believed to have lower risk of vascular thrombosis. We examined the prevalence of aPL including lupus anticoagulant (LAC), anticardiolipin (aCL) and anti-beta2-glycoprotein I (anti-beta2-GPI) antibodies, the level of thrombotic risk, and the association of aPL with thrombotic and pregnancy outcomes in a Chinese cohort with SLE at the university lupus clinic during the period 1986-2003.


METHODS
aPL were measured in 272 SLE patients, and medical records were reviewed for vascular thrombosis and pregnancy outcomes.


RESULTS
The prevalence of LAC, IgG aCL, and IgG anti-beta2-GPI antibodies was 22.4%, 29.0%, and 7.7%, respectively. There were 38 episodes of thrombosis after a mean duration of followup of 11.0 +/- 6.8 SD years, giving a thrombotic rate of 1.26/100 patient-years. All aPL were shown to be associated with vascular thrombosis. IgG anti-beta2-GPI antibodies were found to be associated with recurrent thrombosis [8.0/100 patient-years or 25.0% (7/28)]. Patients taking hydroxychloroquine were found to have fewer thrombotic complications than those who were not (OR 0.17, 95% CI 0.07-0.44; p < 0.0001). LAC was the strongest factor associated with recurrent miscarriages [relative risk 12.3, 95% CI 1.22-123.31; p = 0.03). The diagnosis of secondary antiphospholipid syndrome was satisfied in 8.9% of patients.


CONCLUSION
The lifetime and recurrent thrombotic rates in our patients with aPL were not particularly different from those in the literature. However, the lower prevalence of aPL in our cohort may suggest a role of other prothrombotic factors in predisposition to thrombosis.
24873072
Analysis of risk factors for the development of thrombotic complications in antiphospholipid antibody positive lupus patients
The objective of this study was to characterize risk factors for thrombotic events in lupus patients. A total of 272 lupus patients were followed up for five years during which the presence of aPL antibodies [anticardiolipin (aCL), anti-beta2-glycoprotein I (aβ2GPI) and lupus anticoagulant (LAC)] were determined, and all thrombotic incidents and antithrombotic therapy-related data were collected. At baseline, three groups were constituted, an aPL–group with 107 aPL negative patients, an aPL+ group with 81 aPL positive patients without clinical thrombosis and a secondary antiphospholipid syndrome (APS) group with 84 aPL+ patients who met the Sapporo criteria. LAC was more common in the APS than the aPL+ group (32.1% versus 9.9%, P < 0.001). The prevalence of clinical thrombotic events was significantly higher when all three types of aPL were present compared to only aCL positive cases. During follow up, aPL appeared in 7.5% of the aPL - group, and 2.8% of this group had thrombotic complications. In the aPL + group, thrombotic events reoccurred in 1.9% of those receiving antithrombotic prophylaxis and 6.9% of those without primary prophylaxis. Despite anticoagulant therapy, thrombotic events reoccurred in 8.3% of the APS group. These findings indicate that LAC, constant and cumulative presence of aPL and previous thrombosis are positive predictors for the development of thrombotic complication in lupus patients.
23515621
[Factors related to the risk of thrombosis in patients with lupus and antiphospholipid antibodies].
BACKGROUND AND OBJECTIVE
Antiphospholipid antibodies (aPL) are frequently associated with eritematosus systemic lupus (SLE) and increases the risk of thrombosis. The aim of the study was to analize risk factors of thrombosis and its temporal profile in subjects with SLE.


PATIENTS AND METHOD
One hundred and two SLE patients -mean age: 37.5 years (range: 8-85); 90 women; mean of follow-up: 72 months (range: 9-324); 41 (40.2%) with aPL positive- were included in the study. Actuarial Kaplan-Meier curves were used to assess the thrombosis risk and Cox proportional hazard model was used to evaluate factors associated with the risk.


RESULTS
13 thrombotic events occurred in the group with aPL positive (mean of follow up: 83.5 months) and 5 events in aPL negative group (mean of follow up: 72 months). The event-rates were 3.93 and 0.96/100 patients/year for each group, respectively. Survival curves showed a significantly higher risk of thrombotic events in the patients with positive aPL as compared to the aPL negative group, and the risk still present throughout the observational time. Activated partial thromboplastine time up to 37 s was significantly associated with thrombosis risk (p = 0.003). Furthermore, positivity of lupus anticoagulant and proteinuria > 2.5 g/day tended to increase thrombotic risk, although they did not achieve statistical significance.


CONCLUSIONS
In patients with SLE and aPL, risk of first thrombosis remains over the years, and a large activated partial thromboplastine time was the most important risk factor.
46469146
Outcome of patients with anticardiolipin antibodies: a 10 year follow-up of 52 patients
We report a 10-year follow-up on 52 patients with raised levels of anticardiolipin antibodies (aCL) who were first seen at our tertiary referral centre in 1986. The clinical and serological features of these 52 patients are described. Thirty-one patients had the antiphospholipid syndrome (APS) in 1986. Nine of these patients (29%) had further thrombotic events during the follow-up period. Of the other 21 aCL positive patients without clinical manifestations of APS, 11 (52%) developed the syndrome over this period. Five patients (10%) died during the follow-up. Close monitoring of patients with connective tissue diseases and aCL is essential as the likelihood of developing antiphospholipid syndrome is high.
21372767
Effect of antimalarials on thrombosis and survival in patients with systemic lupus erythematosus
Antimalarials have shown beneficial effects on systemic lupus erythematosus (SLE) activity. Our aim was to investigate whether antimalarials protect against thrombosis and influence survival in SLE patients. A prospective cohort including 232 patients with SLE were included in the study at the time of lupus diagnosis. End points were documented thrombosis and death due to any cause. A Cox regression-multiple-failure time survival analysis model was fitted to establish the effect of antimalarials on the development of thrombosis. Kaplan-Meier survival curves and propensity score adjusted-Cox regression analysis were performed to investigate the effect of antimalarials use on survival. Of our subjects, 204 patients (88%) were women. 230 patients (99%) were white. 150 patients (64%) had ever received antimalarials. Median time on antimalarials was 52 months (range three to 228 months). The Cox multiple-failure time survival analysis showed that taking antimalarials was protective against thrombosis (HR 0.28, 95%CI 0.08-0.90), while aPL-positivity (HR 3.16, 95%CI 1.45-6.88) and previous thrombosis (HR 3.85, 95%CI 1.50-9.91) increased the risk of thrombotic events. Twenty-three patients died, 19 of whom (83%) had never received antimalarials. No patient treated with antimalarials died of cardiovascular complications. Cumulative 15-year survival rates were 0.68 for never versus 0.95 for ever treated patients (P < 0.001). Age at diagnosis and propensity score-adjusted HR for antimalarials ever versus never users was 0.14 (95%CI 0.04-0.48). Our study shows a protective effect of antimalarials against thrombosis and an increased survival of SLE patients taking these drugs. These data support the routine use of antimalarials in all patients with SLE.
35232838
A cross-sectional study of clinical thrombotic risk factors and preventive treatments in antiphospholipid syndrome.
OBJECTIVE
Antiphospholipid antibodies (aPL) are major risk factors for thrombosis. Other clinical factors exist in antiphospholipid syndrome (APS) patients which may have an additive or preventive effect on thrombosis. We therefore performed a cross-sectional study to analyse additive clinical thrombotic risk factors and possible preventive treatments in APS patients, and to compare the results with those obtained in asymptomatic aPL-positive (no history of vascular thrombosis or pregnancy morbidity) patients.


METHODS
We identified 77 APS patients with non-gravid thrombotic events (group A) and 56 asymptomatic aPL-positive patients (group B). The study periods were defined as 6 months prior to the time of first vascular event in group A and 6 months prior to the patient's last visit in group B. Medical records were reviewed to evaluate the incidence of hypertension, diabetes mellitus, hypercholesterolaemia, regular cigarette smoking, oral contraceptive use or hormone replacement therapy, surgical procedures, pregnancy with or without an APS-related event, malignancy and infections. In addition, any history of thrombocytopenia or the use of aspirin, hydroxychloroquine, corticosteroids or immunosuppressives during the study periods was recorded. Bivariate statistical analysis and logistic regression tests were performed to compare groups.


RESULTS
In group A, 75% (n=58) of patients and in group B 48% (n=27) of patients had at least one of the additional risk factors during the study periods. In the bivariate analysis, pregnancy (P=0.005) and surgical procedures (P=0.04) were significantly more frequent in group A, while aspirin (P<0.001), hydroxychloroquine (P<0.001) and corticosteroids (P=0.002) were used significantly more frequently in group B. In logistic regression, the probability of an event was decreased by taking aspirin and/or hydroxychloroquine. In women only, the probability of an event was increased with thrombocytopenia and pregnancy or surgical procedures. The incidences of hypertension and smoking and the presence of more than one risk factor were significantly associated with arterial thrombosis but not venous thrombosis.


CONCLUSION
While traditional risk factors were similar between groups, pregnancy and surgical procedures increased the risk of thrombosis. Hypertension and smoking were associated with arterial events. Possessing a combination of risk factors may increase the occurrence of arterial thrombosis but not venous thrombosis. Use of aspirin and/or hydroxychloroquine may be protective against thrombosis in asymptomatic aPL-positive individuals.
26086087
Clinical efficacy and side effects of antimalarials in systemic lupus erythematosus: a systematic review
Background: Antimalarial drugs (AMs), chloroquine (CQ) and hydroxychloroquine (HCQ), are frequently withdrawn in patients with lupus with either severe or remitting disease. However, additional effects beyond immunomodulation have been recently described. The aim of the present work was to analyse all the published evidence of the beneficial and adverse effects of AM therapy in systemic lupus erythematosus (SLE). Methods: A systematic review of the English literature between 1982 and 2007 was conducted using the MEDLINE and EMBASE databases. Randomised controlled trials (RCTs) and observational studies were selected. Case reports were excluded except for toxicity reports. The GRADE system was used to analyse the quality of the evidence. Results: A total of 95 articles were included in the systematic review. High levels of evidence were found that AMs prevent lupus flares and increase long-term survival of patients with SLE; moderate evidence of protection against irreversible organ damage, thrombosis and bone mass loss. Toxicity related to AMs is infrequent, mild and usually reversible, with HCQ having a safer profile. In pregnant women, high levels of evidence were found that AMs, particularly HCQ, decrease lupus activity without harming the baby. By contrast, evidence supporting an effect on severe lupus activity, lipid levels and subclinical atherosclerosis was weak. Individual papers suggest effects in preventing the evolution from SLE-like to full-blown SLE, influencing vitamin D levels and protecting patients with lupus against cancer. Conclusions: Given the broad spectrum of beneficial effects and the safety profile, HCQ should be given to most patients with SLE during the whole course of the disease, irrespective of its severity, and be continued during pregnancy.
25556461
In vivo inhibition of antiphospholipid antibody‐induced pathogenicity utilizing the antigenic target peptide domain I of β2‐glycoprotein I: proof of concept
Summary.  Objectives: In the antiphospholipid syndrome (APS), the immunodominant epitope for the majority of circulating pathogenic antiphospholipid antibodies (aPLs) is the N‐terminal domain I (DI) of β2‐glycoprotein I. We have previously shown that recombinant DI inhibits the binding of aPLs in fluid phase to immobilized native antigen, and that this inhibition is greater with the DI(D8S/D9G) mutant and absent with the DI(R39S) mutant. Hence, we hypothesized that DI and DI(D8S/D9G) would inhibit aPL‐induced pathogenicity in vivo. Methods: C57BL/6 mice (n = 5, each group) were injected with purified IgG derived from APS patients (IgG‐APS, 500 μg) or IgG from normal healthy serum (IgG‐NHS) and either recombinant DI, DI(R39S), DI(D8S/D9G), or an irrelevant control peptide (at 10–40 μg). Outcome variables measured were femoral vein thrombus dynamics in treated and control groups following standardized vessel injury, expression of vascular cell adhesion molecule‐1 (VCAM‐1) on the aortic endothelial surface, and tissue factor (TF) activity in murine macrophages. Results: IgG‐APS significantly increased thrombus size as compared with IgG‐NHS. The IgG‐APS thrombus enhancement effect was abolished in mice pretreated with recombinant DI (P ≤ 0.0001) and DI(D8S/D9G) (P ≤ 0.0001), but not in those treated with DI(R39S) or control peptide. This inhibitory effect by DI was dose‐dependent, and at lower doses DI(D8S/D9G) was a more potent inhibitor of thrombosis than wild‐type DI (P ≤ 0.01). DI also inhibited IgG‐APS induction of VCAM‐1 on the aortic endothelial surface and TF production by murine macrophages. Conclusion: Our findings in this proof‐of‐concept study support the development of recombinant DI or the novel variant DI(D8S/D9G) as a potential future therapeutic agent for APS.
22120554
A non-complement-fixing antibody to β2 glycoprotein I as a novel therapy for antiphospholipid syndrome.
A single-chain fragment variable (scFv) recognizing β2-glycoprotein 1 (β2GPI) from humans and other species was isolated from a human phage display library and engineered to contain an IgG1 hinge-CH2-CH3 domain. The scFv-Fc directed against β2GPI domain I-induced thrombosis and fetal loss, thus mimicking the effect of antibodies from patients with antiphospholipid syndrome (APS). Complement is involved in the biological effect of anti-β2GPI scFv-Fc, as demonstrated by its ability to promote in vitro and in vivo complement deposition and the failure to induce vascular thrombosis in C6-deficient rats and fetal loss in C5-depleted mice. A critical role for complement was also supported by the inability of the CH2-deleted scFv-Fc to cause vessel occlusion and pregnancy failure. This antibody prevented the pathological effects of anti-β2GPI antibodies from APS patients and displaced β2GPI-bound patient antibodies. The CH2-deleted antibody represents an innovative approach potentially useful to treat APS patients refractory to standard therapy.
541032
The pathogenesis of the antiphospholipid syndrome.
The antiphospholipid syndrome is a prothrombotic disorder associated with autoantibodies. It is associated with obstetrical complications (mainly spontaneous abortion) as well as venous and arterial thrombotic risks. Insights into disease mechanisms have led to new therapies.
2316042
A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome
Background β2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of β2GPI generated by anti-β2GPI antibodies is pathologically important, in contrast to monomeric β2GPI which is abundant in plasma. Principal Findings We created a dimeric inhibitor, A1-A1, to selectively target β2GPI in β2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of β2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of β2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of β2GPI present in human serum, β2GPI purified from human plasma and the individual domain V of β2GPI. We demonstrated that when β2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of β2GPI to cardiolipin, regardless of the source of β2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of β2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-β2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric β2GPI to cardiolipin. Conclusions Our results suggest that the approach of using a dimeric inhibitor to block β2GPI in the pathological multivalent β2GPI/antibody complexes holds significant promise. The novel inhibitor A1-A1 may be a starting point in the development of an effective therapeutic for antiphospholipid syndrome.
11098061
Inhibition of thrombotic properties of persistent autoimmune anti-β2GPI antibodies in the mouse model of antiphospholipid syndrome.
Antiphospholipid syndrome (APS) is an autoimmune disorder with increased risk for thrombosis and pregnancy losses. β2-glycoprotein I (β2GPI) is the major antigen for clinically relevant antibodies in APS. We engineered a molecule, A1-A1, which interferes with 2 prothrombotic mechanisms in APS: the binding of β2GPI to negatively charged cellular surfaces and ApoE receptor 2. We studied how A1-A1 affects arterial thrombosis in vivo in lupus-prone (NZW × BXSB)F1 male mice. For the first time, we demonstrated that A1-A1 efficiently reduces thrombus size in vivo in the presence of chronic autoimmune anti-β2GPI antibodies. We have shown that A1-A1 interferes with thrombotic properties of β2GPI/antibody complexes and does not affect normal thrombus formation in the absence of anti-β2GPI antibodies. A1-A1 inhibits prothrombotic properties of β2GPI/antibody complexes in wild-type mice after acute infusion with anti-β2GPI antibodies, as well as in mice expressing persistent autoimmune anti-β2GPI antibodies. A1-A1 reduced thrombus size in a mouse model of APS in the presence of lupus features, suggesting that A1-A1 might effectively interfere with thrombosis not only in primary APS but also in APS secondary to lupus. Our results suggest that A1-A1 could be a prototype for an antithrombotic drug in APS.
9069767
Antiphospholipid syndrome: from pathogenesis to novel immunomodulatory therapies.
Antiphospholipid syndrome (APS) is characterized by recurrent thrombosis and pregnancy morbidity in association with the persistent presence of circulating antiphospholipid antibodies (aPL). APS remains the most frequent cause of acquired hypercoagulability and recurrent miscarriage. Long-term anticoagulation therapy is the only treatment with proven benefit in the APS. Anticoagulation is not effective in all patients and carries a risk of bleeding. Recent improvements in the understanding of the pathogenic mechanisms have led to the identification of potential targets and future therapies for APS. In contrast to non-specific anticoagulation, the emergence of immunomodulatory drugs provides the possibility of interfering with specific pathogenic pathways. Novel therapies might be used in the future for APS.
24379681
The NF-κB specific inhibitor DHMEQ prevents thrombus formation in a mouse model of antiphospholipid syndrome.
BACKGROUND
β2-glycoprotein I (β2GPI)-dependent antiphospholipid antibodies (aPLs) are considered to play a pivotal pathogenic role in antiphospholipid syndrome (APS) by inducing the expression of tissue factor, inflammatory cytokines, and chemokines, most of which are dependent upon the NF-κB pathway. Therefore, the NF-κB is regarded as a promising target for the development of a novel therapeutic strategy. However, progress has been limited owing to the fact that there are no widely-used in vivo models, or highly specific inhibitors.


OBJECTIVE
This study aimed to test the effects of an NF-κB-specific inhibitor, DHMEQ, in preventing thrombus formation using an original mouse model of APS.


MATERIALS AND METHODS
Specificity of a monoclonal aPL WB-6 was examined by ELISA. WB-6 was injected into normal BALB/c mice with or without DHMEQ treatment. A pulse laser was radiated to a cutaneous vein in the window of a dorsal skinfold chamber attached to the mouse and thrombus formation was observed and recorded under a microscope.


RESULTS
WB-6 bound preferentially to the caldiolipin (CL)-β2GPI complex rather than to CL alone, or β2GPI alone. WB-6, but not isotype-matched control antibody, induced a prothrombotic state in the mice by inducing tissue factor expression upon circulating monocytes, resulting in thrombus formation at the site of laser-induced endothelial injury. This diathesis was almost completely ameliorated by DHMEQ treatment.


CONCLUSIONS
Inhibition of the NF-κB pathway is a promising strategy for the development of a novel treatment for APS.
25253414
Antiphospholipid syndrome treatment beyond anticoagulation: are we there yet?
Persistently positive antiphospholipid antibodies in association with thromboses and/or pregnancy morbidity is the hallmark of the antiphospholipid syndrome. The management of antiphospholipid antibody-positive patients has been focused on utilizing anti-thrombotic medications such as heparin or warfarin. Given that our understanding of the molecular mechanisms of antiphospholipid antibody-mediated thrombosis has been growing, it is highly likely that the current ‘anti-thrombotic’ approach to these patients will be replaced by an ‘immunomodulatory’ approach in the near future. This review article will address the experimental and/or clinical evidence behind some of these potential ‘immunomodulatory’ approaches (tissue factor inhibition, P38 mitogen-activated protein kinase inhibition, nuclear factor-κB inhibition, platelet glycoprotein receptor inhibition, hydroxychloroquine, statins, inhibition of β2GPI and/or anti-β2GPI binding to target cells, complement inhibition, and B cell inhibition) in antiphospholipid syndrome.
17198140
Characterization of monocyte tissue factor activity induced by IgG antiphospholipid antibodies and inhibition by dilazep.
Increasing evidence suggests that autoantibodies directly contribute to hypercoagulability in the antiphospholipid syndrome (APS). One proposed mechanism is the antibody-induced expression of tissue factor (TF) by blood monocytes. Dilazep, an antiplatelet agent, is an adenosine uptake inhibitor known to block induction of monocyte TF expression by bacterial lipopolysaccharide. In the current study we characterized the effects of immunoglobulin G (IgG) from patients with APS on monocyte TF activity and investigated whether dilazep is capable of blocking this effect. IgG from 13 of 16 patients with APS significantly increased monocyte TF activity, whereas normal IgG had no effect. Time-course experiments demonstrated that APS IgG-induced monocyte TF mRNA levels were maximal at 2 hours and TF activity on the cell surface was maximal at 6 hours. Dilazep inhibited antibody-induced monocyte TF activity in a dose-dependent fashion but had no effect on TF mRNA expression. The effect of dilazep was blocked by theophylline, a nonspecific adenosine receptor antagonist. In conclusion, IgG from certain patients with APS induce monocyte TF activity. Dilazep inhibits the increased expression of monocyte TF activity at a posttranscriptional level, probably by way of its effect as an adenosine uptake inhibitor. Pharmacologic agents that block monocyte TF activity may be a novel therapeutic approach in APS.
24022980
Dilazep and dipyridamole inhibit tissue factor expression on monocytes induced by IgG from patients with antiphospholipid syndrome.
AIM
To investigate whether antiplatelet agents, dilazep and dipyridamole, inhibit tissue factor (TF) expression on monocytes induced by IgG from patients with antiphospholipid syndrome (APS).


METHODS
Freshly isolated peripheral blood monocytes were allowed to adhere on plastic and then cultured in media containing patient or control antibodies and/or other agonists with or without dilazep or dipyridamole. The TF activity on monocytes was investigated by measuring factor VIIa-dependent generation of factor Xa, using a chromogenic substrate and the TF mRNA expression was examined by real-time PCR (TaqMan PCR).


RESULTS
The TF activity on monocytes induced by APS IgG (250 mg/L) was inhibited by dilazep (0.15-150 micromol/L) and dipyridamole (0.2-200 micromol/L) in a dose-dependent fashion. But, the TF mRNA expression induced by APS IgG was not inhibited. Theophylline (500 micromol/L), an adenosine receptor antagonist, could counteract the inhibitory effect of dilazep and dipyridamole on TF activity.


CONCLUSION
Antiplatelet agents, dilazep and dipyridamole, block APS IgG-induced monocytes TF expression at a post-transcriptional level, partly by adenosine receptor pathway. Pharmacological agents that block monocytes TF activity, such as dilazep and dipyridamole, are a novel therapeutic approach in APS.
25738641
Management of refractory anti-phospholipid syndrome.
Anti-phospholipid syndrome (APS) is an autoimmune prothrombotic disorder characterised by the predisposition to venous and/or arterial thrombosis and obstetric morbidity. Management of APS centres on attenuating the procoagulant state whilst balancing the risks of anticoagulant therapy. Cases of recurrent thromboses and obstetric complications occur despite optimum therapy. Alternative therapies for refractory cases are subject to disparity among clinicians due to the current lack of clinical evidence present. This review aims to address the current management strategies for refractory thrombotic and obstetric cases and future therapeutic interventions. The role and current clinical evidence of using long term low molecular weight heparin (LMWH) as an alternative to warfarin therapy for refractory thromboses is evaluated. Potential alternatives for thromboses including statins, hydroxychloroquine, Rituximab are reviewed as well as the additional avenues to target in the future as the pathogenic mechanisms of APS are unveiled. The optimal management for refractory obstetric APS cases is subject to controversy. This review focuses and assesses the current evidence for the uses of low dose prednisolone, intravenous immunoglobulin and hydroxycholoroquine in obstetric cases. The treatment modalities for the management of refractory APS require further clinical evidence.
24691452
Protein disulfide isomerase inhibitors constitute a new class of antithrombotic agents.
Thrombosis, or blood clot formation, and its sequelae remain a leading cause of morbidity and mortality, and recurrent thrombosis is common despite current optimal therapy. Protein disulfide isomerase (PDI) is an oxidoreductase that has recently been shown to participate in thrombus formation. While currently available antithrombotic agents inhibit either platelet aggregation or fibrin generation, inhibition of secreted PDI blocks the earliest stages of thrombus formation, suppressing both pathways. Here, we explored extracellular PDI as an alternative target of antithrombotic therapy. A high-throughput screen identified quercetin-3-rutinoside as an inhibitor of PDI reductase activity in vitro. Inhibition of PDI was selective, as quercetin-3-rutinoside failed to inhibit the reductase activity of several other thiol isomerases found in the vasculature. Cellular assays showed that quercetin-3-rutinoside inhibited aggregation of human and mouse platelets and endothelial cell-mediated fibrin generation in human endothelial cells. Using intravital microscopy in mice, we demonstrated that quercetin-3-rutinoside blocks thrombus formation in vivo by inhibiting PDI. Infusion of recombinant PDI reversed the antithrombotic effect of quercetin-3-rutinoside. Thus, PDI is a viable target for small molecule inhibition of thrombus formation, and its inhibition may prove to be a useful adjunct in refractory thrombotic diseases that are not controlled with conventional antithrombotic agents.
5116596
Mitochondrial dysfunction in antiphospholipid syndrome: implications in the pathogenesis of the disease and effects of coenzyme Q(10) treatment.
The exact mechanisms underlying the role of oxidative stress in the pathogenesis and the prothrombotic or proinflammatory status of antiphospholipid syndrome (APS) remain unknown. Here, we investigate the role of oxidative stress and mitochondrial dysfunction in the proatherothrombotic status of APS patients induced by IgG-antiphospholipid antibodies and the beneficial effects of supplementing cells with coenzyme Q(10) (CoQ(10)). A significant increase in relevant prothrombotic and inflammatory parameters in 43 APS patients was found compared with 38 healthy donors. Increased peroxide production, nuclear abundance of Nrf2, antioxidant enzymatic activity, decreased intracellular glutathione, and altered mitochondrial membrane potential were found in monocytes and neutrophils from APS patients. Accelerated atherosclerosis in APS patients was found associated with their inflammatory or oxidative status. CoQ(10) preincubation of healthy monocytes before IgG-antiphospholipid antibody treatment decreased oxidative stress, the percentage of cells with altered mitochondrial membrane potential, and the induced expression of tissue factor, VEGF, and Flt1. In addition, CoQ(10) significantly improved the ultrastructural preservation of mitochondria and prevented IgG-APS-induced fission mediated by Drp-1 and Fis-1 proteins. In conclusion, the oxidative perturbation in APS patient leukocytes, which is directly related to an inflammatory and pro-atherothrombotic status, relies on alterations in mitochondrial dynamics and metabolism that may be prevented, reverted, or both by treatment with CoQ(10).