A new study investigated the risk factors for developing a severe form of COVID-19 in patients with multiple sclerosis. Researchers found risk factors for severe forms of COVID-19 were neurological disability, age, and obesity, but no link was found between disease-modifying therapies exposure and COVID-19 severity. The identification of these risk factors could provide a rationale for an individual strategy of clinical management in patients with MS during the COVID-19 pandemic.

Risk factors associated with the severity of COVID-19 in patients with MS are unknown. DMTs may modify the risk of developing a severe COVID-19 infection, beside identified risk factors such as age and comorbidities. A new study by French researchers at multiple medical centers set out to describe the clinical characteristics and outcomes in patients with MS and COVID-19 and identify factors associated with COVID-19 severity.

The Covisep registry is a multicenter, retrospective, observational cohort study conducted in MS expert centers and general hospitals and with neurologists collaborating with MS expert centers and members of the Société Francophone de la Sclérose en Plaques. The study included patients with MS presenting with a confirmed or highly suspected diagnosis of COVID-19 between March 1, 2020, and May 21, 2020.

The main outcome was COVID-19 severity assessed on a 7-point ordinal scale with a cutoff at 3. Researchers collected demographics, neurological history, Expanded Disability Severity Scale score, comorbidities, COVID-19 characteristics, and outcomes. Statistical modelling used to estimate the links of collected variables with COVID-19 outcomes.

A total of 347 patients were analyzed. Seventy-three patients (21 percent) had a COVID-19 severity score of 3 or more, and 12 patients died of COVID-19. The median EDSS was 2, and 284 patients (81.8 percent) were receiving DMT. There was a higher proportion of patients with a COVID-19 severity score of 3 or more among patients with no DMT relative to patients receiving DMTs. Statistical modelling determined age, EDSS, and obesity were independent risk factors for a COVID-19 severity score of 3 or more (indicating hospitalization or higher severity). The EDSS was linked with the highest variability of COVID-19 severe outcome, followed by age and obesity.

In this registry-based cohort study of patients with MS, age, EDSS, and obesity were independent risk factors for severe COVID-19; there was no link found between DMTs exposure and COVID-19 severity. The identification of these risk factors should provide the rationale for an individual strategy regarding clinical management of patients with MS during the COVID-19 pandemic.

The findings were published in the journal JAMA Neurology.