Dear Editor, After the coronavirus disease 2019 (COVID-19) pandemic affected the whole world, rheumatologists began to think about how COVID-19 will progress in patients with inflammatory conditions. High cytokine levels play a role in the pathophysiology of COVID-19 infection. Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine known to have a key role in the pathogenesis of chronic immune-mediated diseases. AntiTNF therapy may cause an increase in active tuberculosis, other granulomatous diseases, and serious infections [1]. According to many studies, rheumatological diseases have not been identified as a risk factor for severe COVID-19 infection [2]. Should significantly increased cytokine levels during COVID-19 infection make us consider anticytokine therapies that may be used in the treatment of patients with COVID-19 a risk? We aimed to explore whether the frequency of COVID-19 infection increased, the effect of comorbidities on the frequency of infection, and whether the severity of the disease and need for intensive care support increased in patients who used anti-TNF agents. We performed a retrospective case-control study between March and December 2020 in Sakarya University Training and Research Hospital. Retrospectively, we evaluated whether there was a difference in the frequency and severity of COVID-19 in our patients diagnosed with ankylosing spondylitis (AS), 77 of whom were using anti-TNF and 49 of whom didn't use anti-TNF. Hospitalization and intensive care unit (ICU) requirements were evaluated as endpoints. In the anti-TNF group, patients used adalimumab, etanercept, certolizumab, infliximab, and golimumab. Patients were questioned at an outpatient clinic in person or by phone. Seventy-seven patients with AS using anti-TNF agents (58 males, 19 females) and 49 patients with AS (38 males, 11 females) not using anti-TNF agents were included in the study (p = 0.943). Mean age of patients using antiTNF agents was 41.53 ± 10.38, and mean age of patients not using anti-TNF agents was 42.94 ± 10.86 (p = 0.468). Thirty-three (42.9%) patients were smokers in the antiTNF group, while 23 (46.9%) patients were smokers in the group not using TNFi (p = 0.791). There was 12 pack-year smoking in the anti-TNF group, and 14 pack-year smoking in not using TNFi (p = 0.623). The frequency of diabetes mellitus (DM), hypertension (HT), amiloidosis, familial mediterranean fever (FMF), coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD) was similar in both groups (p = 0.403, p = 0.999, p = 0.521, p = 0.999, p = 0.999, respectively). Six patients using TNFi and 3 patients not using TNFi recovered from COVID-19 infection. However, this result was not statistically significant (p = 0.999). One patient using anti-TNF was hospitalized but with no need for admission to the ICU (p = 0.999). All 9 patients recovering from COVID-19 were male (p = 0.113). There were 2 (22.2%) smokers in the SARS-CoV-2 positive group and 54 (46.2%) smokers in SARS-CoV-2 negative group (p = 0.297). There was 37.5 pack-year smoking in SARS-CoV-2 positive group, and 12 pack-year smoking in SARS-CoV-2 negative group (p = 0.151). Nobody has comorbidities (DM, HT, amiloidosis, FMF, CAD, COPD) in SARS-CoV-2 positive group. There were patients with DM (5.1%), HT (15.4%), amiloidosis (1.7%), FMF (1.7%), CAD (0.9%) and COPD (0.9%) in SARS-CoV-2 negative group (p = 0.999, p = 0.356, p = 0.999, p = 0.999, p = 0.999, p = 0.999, respectively). Having comorbidities was not detected to be associated with frequency of COVID-19. 31 (40.3%) patients were using adalimumab, 25 (32.5%) patients were using etanercept, 13 patients were using (16.9%) certolizumab, 6 (7.8%) patients were using golimumab, and 2 patients (2.6%) were using infliximab in TNF group. Six patients using anti-TNF (2 adalimumab, 1 etanercept, 1 golimumab,2 infliximab) and 3 nonuser patients recovered from COVID-19 (p = 0.999). No statistically significant difference was found between SARS-CoV-2 positive and negative patients in terms of the types of anti TNF they used. Patients were called in March 2020, and they were advised to terminate their anti-TNF therapy, when the COVID-19 pandemic began. Among those who used antiTNF, 2 (33.3%) people who had COVID-19 and 38 (53.5%) people who did not have COVID-19 interrupted treatment (p = 0.419). Anti-TNF users who did not have COVID-19 stopped taking the treatment for an average of 3 months (min 2-max 4 months) starting from March 2020, and the patients who had COVID-19 (p = 0.102) stopped taking the treatment for 1.5 months (min 1-max 2 months). Duration of interrupting TNFi was not significant for the risk of COVID-19. Comorbidities, older age, and the presence of active disease have been associated with worse outcomes in previous studies [3]. In our study, the anti-TNF using and the nonuser groups were similar according to age, sex, and comorbidities. Although comorbidities in COVID-19 are associated with severe disease in the literature, we did not find a significant difference in our study. This result is probably related to our insufficient number of patients. As a result, we found that the use of anti-TNF did not increase the frequency and severity of COVID-19. In a recently published multicenter study, it was stated that the use of biological DMARDs in patients with inflammatory rheumatic diseases was not significantly associated with a worse outcome of COVID-19. But unlike our study, having no comorbidities was associated with a decreased risk of a worse outcome [4]. There are currently studies investigating the therapeutic utility of infliximab and adalimumab in hospitalized COVID-19 patients [5]. The results of these studies are very important. The usability of TNFi in treatment and at which stage of the disease anti-TNF agents can be used are wondered. We will see the course of the disease all over the world after the administration of the COVID-19 vaccines, but we still need more information about effective and safe treatment.
The authors declare that there is no conflict of interest.
The authors did not receive support from any organization for this work.