Risk factors for severe COVID-19 in patients with multiple sclerosis

Increased disability, old age, black race, cardiovascular disease, and recent corticosteroid treatment are risk factors for poorer outcomes associated with SARS-CoV-2 infection in patients with multiple sclerosis (MS), according to a study published in JAMA Neurology.

As MS involves the immune system, and treatment of these patients can have a significant impact on the immune response, data on clinical outcomes and risk factors associated with outcomes in patients with MS and concomitant SARS-CoV-2 are critical.

The aim of the current study was to assess clinical outcomes and identify risk factors associated with SARS-CoV-2 infection in the North American registry of MS patients.

Using data from the COVID-19 registry in the MS registry, the study researchers identified patients with MS and laboratory-positive SARS-CoV-2 infection or highly suspected COVID-19 between April 1, 2020 and December 12, 2020.

Clinicians reported the course of COVID-19, and the answers were used to determine the severity of COVID-19: not hospitalized, only hospitalized, admission to the intensive care unit and / or required ventilator support and death.

The study sample included 1,626 patients (74% women; mean age 47.7 years), including 1,345 patients with laboratory-positive SARS-CoV-2 infection and 281 patients with suspected COVID-19. Most participants had relapsing-remitting MS (1255 patients, 80.4%).

During the study period, the overall mortality rate was 3.3% (54 patients), including 43 patients (79.6%) who were hospitalized, 29 patients (53.7%) admitted to the ICU, and 25 patients %) who needed fan support.

Mortality increased with age, with the highest mortality rate among patients aged 75 years and older (22.6%), while mortality did not occur in those younger than 35 years. There was a 76.5% increased risk of death for every 10 years of age increase.

Mortality was also significantly higher for black patients compared to white patients with MS (4.2% vs. 3.5%, respectively). After adjusting for covariates, black patients with MS had a 47% higher chance of hospitalization alone, more than doubling the risk of admission to ICU and / or ventilation, but did not increase the risk of mortality.

Outpatient disability is associated with an increased chance of all levels of clinical severity, compared with those not hospitalized. The request for walking assistance is associated with at least a double risk of all clinical severity levels. Being unbalanced is associated with a 2.8-fold increased probability of hospitalization alone, a 3.5-fold higher probability of admission and / or ventilation at the ICU, and a 25-fold higher probability of death, compared with completely outpatients.

Cardiovascular disease was associated with a 91% increased risk of hospitalization alone and a more than threefold increased risk of death from COVID-19.

Rituximab treatment was associated with a 4.5-fold increased risk of hospitalization due to COVID-19, and ocrelizumab with a 1.63-fold increased risk. However, no other level of clinical severity is associated with these treatments. Corticosteroid use in the past 2 months has been associated with a twofold increased risk of hospitalization and a fourfold increased risk of death.

The study had several limitations, including potential reporting bias and missing data on compliance with public health recommendations.

“Identification of risk factors may improve the treatment of patients with MS and COVID-19 by alerting clinicians to patients who require more intensive treatment or monitoring,” the study researchers concluded.

Data Disclosure: Several study authors stated that it is related to the pharmaceutical industry. See the original reference for a complete list of the author’s discoveries.


Salter A, Fox RJ, Newsome SD, et al. Outcomes and risk factors associated with SARS-CoV-2 infection in the North American registry of patients with multiple sclerosis. JAMA Neurol. Published online March 19, 2021. doi: 10.1001 / jamaneurol.2021.0688