Antiphospholipid antibodies (aPL) are frequently present in antineutrophil cytoplasmic antibody-associated vasculitis (AAV) patients; however, the prognostic impact of aPL in such patients has not been elucidated. The objective of this study was to determine whether persistent aPL positivity in AAV patients was associated with increased long-term damage accrual.
Clinical data were retrospectively collected on all AAV patients who attended the vasculitis clinic at our center over a 4-year period. Data collection included presence of lupus anticoagulant (LAC) and IgG and IgM anticardiolipin (aCL) antibody titers, along with concurrent diagnosis of antiphospholipid syndrome (APS). Accumulation of long-term damage was quantified using the Vasculitis Damage Index (VDI).
Data from 116 AAV patients were analyzed. A total of 34% (n = 40) had persistently positive aCL or LAC or a concurrent diagnosis of APS and were classified as AAV/aPL. A total of 76 patients (66%) were classified as AAV alone. LAC was present in a statistically higher proportion of AAV/aPL patients than those in the AAV-alone group (P < 0.0001). Mean VDI score was significantly higher in the AAV/aPL group at mean ± SD 3.54 ± 1.36 as compared to 1.96 ± 1.42 in the AAV-alone group (P < 0.0001). Major vascular damage scores were significantly higher in the AAV/aPL group, with mean ± SD 0.32 ± 0.59 as compared to 0.07 ± 0.26 in the AAV-alone group (P < 0.007).
Persistently positive occurrence of aPL, in particular LAC, is present in a significant proportion of AAV patients and is associated with a higher VDI score. Clinicians should consider screening AAV patients for aPL.