Multiple sclerosis and COVID-19: How many are at risk?

The coronavirus disease 2019 (COVID-19) pandemic challenges neurologists in counseling multiple sclerosis (MS) patients with respect to their risk for and by severe acute respiratory syndrome coronavirus 2 and in guiding disease-modifying treatment (DMT). The objective was to determine the frequency and distribution of currently known risk factors for COVID-19 mortality in an MS population.

Multiple sclerosis patients with at least one complete case report between January 1, 2015 and December 31, 2019 from the Innsbruck MS database were cross-sectionally included. Frequencies of currently estimated COVID-19 mortality risk factors were analyzed, and the cumulative risk was calculated by a recently developed score. For every risk group, the proportions of patients under DMT and immunosuppressive treatment were determined.

Of 1931 MS patients, 63.4% had low risk of COVID-19 mortality, 26% had mild risk, 8.8% had a moderate risk, whereas a combined 0.9% had high or very high risk of COVID-19 mortality. Of the patients at high or very high risk, only one patient received DMT and none had an immunosuppressive therapy.

In a population-based MS cohort, the proportion of patients at high risk of COVID-19 mortality is below 1%. Importantly, the vast majority of these MS patients did not receive any DMT.