Risk Factors for Severe COVID-19 in Patients with Multiple Sclerosis

Female black hospitalized patient lying in bed looking away while wearing a protective facemask – Lifestyles
There may be numerous risk factors and outcomes associated with SARS-CoV-2 infection in patients with multiple sclerosis.

Increased disability, older age, being of Black race, cardiovascular disease, and recent treatment with corticosteroids are risk factors for worse outcomes associated with SARS-CoV-2 infection in patients with multiple sclerosis (MS), according to study results published in JAMA Neurology.

As MS involves the immune system and treatment for these patients may 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 objective of the current study was to assess the clinical outcomes and to identify risk factors associated with SARS-CoV-2 infection in a North American registry of patients with MS.

Using data from the COVID-19 Infections in MS registry, study researchers identified patients with MS and a 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 responses were used to determine the severity of COVID-19: not hospitalized, hospitalization only, intensive care unit (ICU) admission and/or required ventilator support, and death.

The study sample included 1626 patients (74% women; mean age, 47.7 years), including 1345 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 (46.3%) who required ventilator support.

Mortality increased with age, with highest mortality rate among patients aged 75 years and older (22.6%), while no deaths occurred in those younger than 35 years of age. There was a 76.5% increased risk of death for every 10-year age increase.

Mortality was also significantly higher for Black patients compared with White patients with MS (4.2% vs 3.5%, respectively). After adjusting for covariates, Black patients with MS had a 47% increased odds of hospitalization alone, more than a 2-fold increased risk of ICU admission and/or ventilation, but no increased mortality risk.

Ambulatory disability was associated with increased odds of all clinical severity levels, compared with those not hospitalized. Requiring assistance to walk was associated with at least a 2-fold risk of all clinical severity levels. Being nonambulatory was associated with 2.8-fold increased odds of hospitalization alone, a 3.5-fold increase for ICU admission and/or ventilation, and a 25-fold increased odds of death, compared with fully ambulatory patients.

Cardiovascular disease was associated with a 91% increased risk of hospitalization alone and more than a 3-fold increased risk of death from COVID-19.

Treatment with rituximab was associated with a 4.5-fold increased risk of hospitalization for COVID-19, and ocrelizumab was associated with a 1.63-fold increased risk. However, no other levels of clinical severity were associated with these treatments. Corticosteroid use in the past 2 months was associated with a 2-fold increased risk of hospitalization and 4-fold increased risk of death.

The study had several limitations, including potential reporting bias and missing data on the adherence to public health recommendations.

“Identification of risk factors can improve the treatment of patients with MS and COVID-19 by alerting clinicians of patients requiring more intense treatment or monitoring,” concluded the study researchers.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


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