The effects of COVID-19 infection on the mortality of patients receiving rituximab therapy

Background Rituximab (RTX) is an important immunosuppressive agent used for many rheumatologic diseases. This study investigated the factors affecting mortality and mortality due to COVID-19 infection in patients receiving RTX. Methods From March 2020 to November 2021, 111 patients who were followed up at a tertiary center with a diagnosis of any rheumatologic disease and who were diagnosed with COVID-19 were enrolled out of 336 patients who received at least one dose of RTX. Age, COVID-19 vaccination status, comorbidities, and some laboratory parameters were determined. The association between them and COVID-19 infection was investigated. In addition, patients were divided into two groups: those with rheumatoid arthritis (RA) and those without RA, and factors affecting mortality were studied. Results Thirty (27.0%) of the total 111 patients treated with RTX who tested positive for COVID-19 died. Among these patients, 19 (32.7%) of 58 patients diagnosed with RA died. Of the 53 patients diagnosed with non RA disease, 11 (20.7%) died. Age (p = 0.003, OR: 1.058, 95% CI: 1.025-1.097) and age at diagnosis (p = 0.047, OR: 1.032, 95% CI: 1.000-1.064) were the lowest against COVID-19 infection. Rate of vaccination of at least two doses (p = 0.000, OR: 0.170, 95% CI: 0.065-0.491), number of comorbid conditions (p = 0.001, OR: 1.530, 95% CI: 1.202-1.949), CKD (p = 0.003, significance was found between OR: 7.000, 95% CI: 1.926-25.439) and DM (p = 0.000, OR: 6.978, 95% CI: 2.499-19.483) and death. Conclusion As a result of the study, it was found that RTX treatment in particular increased the risk of death from COVID-19 infection. However, vaccination against COVID-19 has a very important place in this patient group. It is important that vaccination is administered at the full dose and adjusted according to the RTX treatment time, and that the dose and timing of RTX treatment are regulated.