COVID‐19 disease frequency, risk factors, and re‐infection rates in patients with autoimmune rheumatic disease receiving rituximab

Abstract

Rituximab, which is used in autoimmune rheumatic diseases (ARD), can cause both an increased risk of development of COVID-19 disease and re-infection due to its potent and long-acting immunosuppression. So, we aimed to evaluate the frequency, risk factors and re-infection rates of COVID-19 in ARD patients receiving rituximab. A single-center retrospective study was performed with patients receiving rituximab for ARD in 12 months before the onset of COVID-19 in Turkey. The data regarding severe acute respiratory syndrome-coronavirus 2 reverse transcription polymerized chain reaction (RT-PCR) test, clinical, laboratory, and mortality data of all patients were collected from medical records. Logistic regression analysis was used for predictors of COVID-19 disease. COVID-19 re-infection was defined as RT-PCR positivity and recurrence of acute COVID-19 symptoms after at least 1 negative RT-PCR in patients with clinical improvement. Ninety-eight ARD patients with rituximab were evaluated and 23 (23%) of them had COVID-19. The presence of hypogammaglobulinemia increased the risk of COVID-19 disease 8-fold. COVID-19 pneumonia occurred in 13 (57%) and these patients' age was higher than those without pneumonia (59.6 ± 11.8 vs 44.9 ± 14.2 years, P=0.013). Mortality due to COVID-19 was 13% and COVID-19 re-infection was seen in 20% of survivors. Regardless of the underlying rheumatic disease and organ involvements, hypogammaglobulinemia in ARD could be a risk factor for COVID-19 development, and advanced age could be for COVID-19 severity. Moreover, COVID-19 re-infection rates are high.