Severe outcomes of COVID-19 among patients with multiple sclerosis under anti-CD-20 therapies: A systematic review and meta-analysis

BACKGROUND: COVID-19 may spread through various ways ranging from asymptomatic to severe forms, until respiratory failure, critical conditions and death occurs. There is a particular concern for patients affected by multiple sclerosis, especially for those under disease-modifying treatments. Some studies have found an association between anti-CD20 therapies (especially rituximab) and severe COVID-19. However, results were not always clear and thus a systematic review was helpful. METHODS: A systematic literature search was performed independently by two authors on the main search tools considering as key inclusion criterion the presence of data on patients under ocrelizumab or rituximab positive to COVID-19. The quality of the included studies was evaluated based on a modified version of the Dutch Cochrane center critical review checklist proposed by MOOSE and in case of missing data an email was sent to the corresponding authors asking for missing information. After excluding case-reports, a random effects meta-analysis of proportions was conducted using the continuity correction and the I(2)statistic was calculated to measure heterogeneity. RESULTS: 29 articles were included in the analysis and the median quality of the articles reached 4/5 after having integrated the additional details provided by the authors. The articles included 5173 patients, of whom 770 (14.8%) and 455 (8.8%) were, respectively, under ocrelizumab and rituximab. Pooled estimates of hospitalization, pneumonia and intensive care unit admission were 18.1%, 14.8% and 3.3%, respectively, while pooled estimate for death was 1.8% overall and 1.6% and 4.5%, respectively, for patients under ocrelizumab and rituximab. CONCLUSION: Patients treated with rituximab seem to be at higher risk of severe COVID-19 outcomes compared to patients under other treatments.