COVID-19 outcomes in persons with multiple sclerosis treated with rituximab

Background: Outcomes of COVID-19 in PwMS (persons with Multiple Sclerosis) on immunosuppressive therapies, particularly B-cell depletors, can be unpredictable. There has been a concern for postponing or avoiding use of Rituximab (RTX) during the COVID-19 pandemic. We report the course and outcomes of COVID-19 in PwMS receiving RTX.

Methods: PwMS receiving RTX who contracted COVID-19 were closely monitored by tele-consultation and/or evaluated during hospital visits. Those requiring hospitalization for oxygen therapy or admission to ICU or expiring due to COVID-19 were considered to have severe disease. Those without desaturation and manageable at home were considered to have mild disease. Disease course and outcomes were noted.

Results: Twelve out of 62 (19.4%) PwMS on RTX therapy developed COVID-19. Four (age 35-49 years; mean 43.5) had severe COVID; three of whom had Secondary Progressive MS (SPMS). One PwMS expired. Two had prolonged fever lasting >1 month. One demonstrated features of SARS-CoV-2 reactivation. Interval from last RTX infusion (average dose 750 mg) to COVID-19 onset ranged 1-4 (mean 3.7) months. Eight PwMS had mild COVID-19 (age 26-54 years; mean 37.7); six had RRMS and two SPMS. RTX dose was lower (average dose 625 mg) and infusion to COVID-19 onset duration was longer, ranging 4-20 (mean 9.5) months. Four patients, two each from mild and severe COVID-19 groups had neurological deterioration, but none had true relapses.

Conclusion: RTX treated PwMS may have unpredictable disease outcomes if they contract COVID-19, but may be at risk of severe disease and persistent infection. In our series higher age, SPMS, shorter interval from RTX infusion to COVID-19 onset and higher dose of RTX were noted amongst those developing severe disease. RTX should be use cautiously during the COVID-19 pandemic and if unavoidable, less frequent and lower doses should be considered. Patients receiving RTX must be counselled to follow strict COVID-19 preventive measures.