Exposure to DMTs Does Not Increase Risk of Severe COVID-19 in MS Patients, Study Finds

Exposure to disease-modifying therapies does not increase multiple sclerosis (MS) patients’ risk of developing a severe form of COVID-19, according to a registry-based study.

However, MS patients who are older, obese, or have severe neurological impairments have a greater risk of developing a severe form of the disease.

Findings were reported in the study, “Clinical Characteristics and Outcomes in Patients With Coronavirus Disease 2019 and Multiple Sclerosis,” published in the journal JAMA Neurology.

MS patients are a population of particular interest during the pandemic because most of them are actively taking medications that suppress the activity of the immune system, which may increase their chances of being infected by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

In its COVID-19 recommendations released in March, the Multiple Sclerosis International Federation stated that “some MS medications might increase the likelihood of developing complications from a COVID-19 infection but this risk needs to be balanced with the risks of stopping treatment.”

However, it is still unclear at this point if the use of disease-modifying therapies (DMTs) — medications that reduce the activity of the immune system to keep inflammation in check — increases the risk MS patients have of being hospitalized with a severe form of COVID-19.

To address this question and identify risk factors that could be associated with severe forms of COVID-19 in MS patients, a group of French investigators carried out a registry-based study that included data from 347 MS patients (mean age of 44.6 years) who received a confirmed or highly likely diagnosis of COVID-19 between March 1 and May 21.

Patient data was part of the Covisep registry, a multicenter registry that contains clinical information gathered from patients followed at MS expert centers and general hospitals, with support from neurologists and members of the Société Francophone de la Sclérose en Plaques in France.

As part of the study, investigators collected a series of demographic and clinical information from patients, including their neurological history, comorbidities, degree of disability imposed by MS, and COVID-19 severity.

The extent of patients’ disability was determined using the expanded disability status scale (EDSS). COVID-19 severity was evaluated using a seven-point ordinal scale, with a cutoff threshold at three, meaning that those scoring three or higher had a severe form of the disease. (A score of 3 means hospitalized but not requiring supplemental oxygen, while a score of 7 represents death.)

Statistical analyses were used to evaluate possible relationships between the different characteristics analyzed and COVID-19 outcomes.

The median EDSS observed in the overall population of patients participating in the study was 2, indicating the presence of minimal disability.

From the 347 patients participating in the study, 73 (21%) had a score of three or higher in the seven-point ordinal scale of COVID-19 severity, and 12 (3.5%) died from the disease.

A total of 284 (81.8%) patients were receiving DMTs. Analyses showed that the percentage of patients with severe COVID-19 was higher among those who had never been exposed to DMTs, compared to those who were actively taking these medications — 46.0% versus 15.5% in the DMT group — indicating the use of DMTs is not linked to a greater risk of severe COVID-19.

“Our data do not support an increased risk of severe outcome associated with DMTs, which should reinforce the recommendation of not stopping current DMTs and not delaying treatment initiation in patients who have higher disease inflammatory activity, risk for relapses, or subsequent disability,” investigators wrote.

Statistical analyses, however, found that being older, having excess weight, and a higher degree of disability were all independent risk factors for severe COVID-19 among MS patients.

“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,” researchers concluded.