Incidence of multiple sclerosis (MS) relapse after COVID-19 infection: A systematic review and meta-analysis

Background: COVID-19 could exacerbate the symptoms of autoimmune diseases such as multiple sclerosis (MS). Literature shows an increase in the incidence of relapse in patients with MS after COVID-19. We designed this systematic review and meta-analysis to estimate the pooled incidence of MS-relapse after COVID-19. Methods: We performed a systematic search in PubMed, Scopus, EMBASE, Web of Science, and Google scholar. Gray literature including references of the references and conference abstracts were also searched to find relevant articles. We extracted data regarding the total number of participants, the name of the first author, publication year, country of origin, mean age, mean disease duration, mean Expanded Disability Status Scale (EDSS), and the number of patients with relapse after COVID. Results: A literature search revealed 5160 articles, after deleting duplicates, 2270 remained. After careful evaluation of the full texts, twelve studies were included for meta-analysis. Totally, 1595 patients with MS who had a history of COVID-19 were evaluated. Most studies were done in Iran. The mean age of included patients ranged between 35 and 49 years, and mean durations of the disease were between 7and 15.4 years. The incidence of relapse ranged between 2% and 20% in included studies. The pooled incidence of relapse after COVID-19 was 7% (95%CI:5-10%) (I2=64%, p<0.001). Conclusions: The results of this systematic review and meta-analysis show that the pooled incidence of MS-related relapse after COVID-19 is 7%.