Incidence, clinical presentation, relapses and outcome of SARS-CoV-2 infection in patients treated with anti-CD20 monoclonal antibodies.

Background Our objective is to describe the presentation and complications, including relapses, of COVID-19 in patients under anti-CD20 treatments. In addition, to describe viral clearance and determine the safety of reintroducing anti-CD20 treatment. Methods Retrospective cohort study of 422 patients under anti-CD20 treatment that was administered from January 1, 2019, to December 31, 2020. Results Fifty-seven patients were diagnosed of COVID-19 (13.5%). 25 patients (43.9%) required hospital admission. 5 patients died (8.8%), 10 developed severe COVID-19 and acute respiratory distress syndrome. Mortality rate was higher among patients infected during the first 3 months following the last dose of anti-CD20 (14.7% vs 0%, p=0,046).The median time of persistence of positive RT-PCR was 22 days (IQR 13-40). Nine out of 52 survivors (17.3%) presented relapses. All of them received the last dose of anti-CD20 less than 6 months before the COVID-19 episode. Clinical presentation was fever (n=8; 88.9%), dyspnea (n=7; 77.8%), cough (n=7; 77.8%), worsening of previous infiltrates (n=5; 55.6%) and new pulmonary infiltrates (n=8; 88.9%). An increase in lymphocytes with CD4/CD8 ratio inversion was observed in all cases. Among the 25 patients who resumed anti-CD20 drug, 4 (16.0%) presented relapses vs 5/28 among those who did not (17.9%), (p=0.857). Conclusion Patients infected with SARS-CoV-2 during the 6 months after anti-CD20 administration had a worse outcome and a higher mortality rate. The duration of infectivity may be longer. Relapses of COVID-19 occurred in more than 15% and were associated with viral replication. Once the infection is resolved, it is safe to restart treatment with anti-CD20.