No Link Between Use of DMT, COVID-19 Severity in Patients With MS, Study Finds

The use of disease-modifying therapy (DMT) was associated with a lower risk of hospitalization for patients with coronavirus disease 2019 (COVID-19), and neurological disability, age, and obesity were independent risk factors for more severe cases of infection for patients with multiple sclerosis (MS).

The past few months of the coronavirus disease 2019 (COVID-19) pandemic have surfaced new concerns for those with chronic diseases, including understanding the risk level for these groups of patients. Multiple sclerosis (MS) is no different, and in March, experts warned that patients should not stop taking their disease-modifying therapies (DMTs).

A study published Friday in JAMA Neurology reiterated those findings, as researchers shared data from a patient registry in France that sought to identity specific risks for those with MS. The registry, with 347 patients, found that independent risk factors for severe forms of COVID-19 were neurological disability, age, and obesity, but no association was found with exposure to DMTs. And in univariate analysis, the presence of DMT was associated with a lower risk of hospitalization.

The study categorized DMT therapy according to systemic infection risk:

  • No risk—interferon beta and glatiramer
  • Low risk—teriflunomide, dimethylfumarate, natalizumab, and other drugs (mycophenolate mofetil, methotrexate, and cyclophosphamide)
  • Intermediate or high risk—fingolimod, anti-CD20 therapies, cladribine, and alemtuzumab

The Covisep registry is a multicenter, retrospective, observational cohort study conducted in MS clinics in France as well as general hospitals and 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, diagnosed with either with a polymerase chain reaction test on a nasopharyngeal swab, thoracic CT, or typical symptoms.

The main outcome was COVID-19 severity assessed on a 7-point ordinal scale, ranging from 1 (not hospitalized and no limitations on activities) to 7 (death), with a cutoff at 3 (hospitalized but not requiring supplemental oxygen).

The Expanded Disability Severity Scale (EDSS) score ranged from 0 to 10, with cutoffs at 3 and 6.

Other factors collected included demographics, neurological history, comorbidities, COVID-19 characteristics, and outcomes. Univariate and multivariate logistic regression models were used to estimate the association of collected variables with COVID-19 outcomes.

Of the 347 patients, 249 were women. There was a mean (SD) disease duration of 13.5 (10.0) years and mean (SD) age of 44.6 (12.8) years, and the majority of patients (81.8%) were receiving DMT.

Seventy-three patients (21.0%) had a COVID-19 severity score of 3 or more; 12 patients (3.5%) died. The median EDSS was 2.0 (range, 0-9.5).

More patients who had no DMT had worse COVID-19, based on a severity score of 3 or more, compared with patients who did take DMTs (46.0% vs 15.5%; P < .001).

Age (odds ratio [OR] per 10 years: 1.9 [95% CI, 1.4-2.5]), EDSS (OR for EDSS 6, 6.3 [95% CI. 2.8-14.4]), and obesity (OR, 3.0 [95% CI, 1.0-8.7]) were independent risk factors for a COVID-19 severity score of 3 or more.

The EDSS was associated with the highest variability of COVID-19 severe outcome (R2, 0.2), followed by age (R2, 0.06) and obesity (R2, 0.01).

Clinical management of patients with MS during the pandemic should be individualized, the authors said, and they stressed that treatment initiation should not be delayed for those with higher disease inflammatory activity, risk for relapses, or subsequent disability.

The researchers noted that DMTs are more frequently prescribed to younger patients, those with a relapsing form of MS, and those with a lower level of disability. They urged that another study using multivariate analysis to estimate the independent outcome of age, disease course, EDSS, and exposure to DMTs be conducted with a larger sample size, because “it is possible that a larger cohort could identify a subgroup of patients with 1 or more DMTs that modify the risk of COVID19. Therefore, the pooling of registries and/or replication of results in other cohorts from several countries will be important to reinforce this result.”

In addition, they said the link between the severity of COVID-19 and the level of neurological disability assessed by EDSS in this group has not been previously reported.


Louapre C, Collongues N, Stankoff B, et al. Clinical characteristics and outcomes in patients with coronavirus disease 2019 and multiple sclerosis. JAMA Neurol. Published online June 26, 2020. doi:10.1001/jamaneurol.2020.2581