Baseline patient characteristics, MS severity impact COVID-19 outcomes

Expanded Disability Scale Status and age served as independent risk factors for severe COVID-19 infection in a multicenter study of patients with MS and COVID-19 presented during an encore session of MSVirtual2020.

Researchers also found that receipt of immunomodulatory disease-modifying therapies (DMTs), including interferon and glatiramer acetate, independently correlated with reduced COVID-19 severity, though they did not demonstrate a link between other DMTs, including immunosuppressive therapies, and COVID-19 severity.

“Risk factors associated with the severity of COVID-19 in patients with MS [are beginning] to be identified from several cohort studies,” the researchers wrote. “DMTs may modify the risk of developing a severe COVID-19 infection, [besides] identified risk factors such as age and comorbidities.”

Céline Louapre, MD, of Pitié-Salpêtrière Hospital in Paris, and colleagues conducted a multicenter, retrospective, observational cohort study of patients with MS who presented with a confirmed or highly suspected diagnosis of COVID-19 between March 1, 2020, and July 14, 2020. COVID-19 severity served as the primary outcome, as evaluated with a 7-point scale ranging from 1 (not hospitalized with no limitations on activities) to 7 (death), with a cutoff at 3 (hospitalized with no supplemental oxygen).

The researchers gathered data on demographics, neurological history, Expanded Disability Severity Score (EDSS) and comorbidities, as well as COVID-19 characteristics and outcomes. They then analyzed the effect of these variables on outcomes related to COVID-19.

Louapre and colleagues included 405 patients (mean age, 44.7 years; women, n = 293; mean disease duration, 13.4 years) in their analysis. Nearly 20% of patients (19.3%; n = 78) had a COVID-19 severity score equal to or greater than 3 and 12 patients (3%) died of COVID-19. The mean EDSS was 2 (range, 0-9.5) and 326 patients (80.5%) were receiving DMT.

The researchers found that patients who were not receiving DMT were more likely to have a COVID-19 severity score of 3 or greater compared with those who received treatment with DMT (39.2% vs. 14.4%; P < .001).

Multivariate logistic regression models demonstrated that age (OR for 10 years = 1.8; 95% CI, 1.4-2.4) and EDSS (OR for EDSS 6 = 4.5; 95% CI, 2-10) represented independent risk factors for a COVID-19 severity score equal to or greater than 3 (hospitalization or higher severity), while immunomodulatory treatment with interferon or glatiramer acetate correlated with a lower risk for a COVID-19 severity score equal to or greater than 3 (OR = 0.2; 95% CI, 0.05-0.8). Louapre and colleagues found that EDSS was associated with the highest variability of a severe COVID-19 outcome (R² = 0.18), followed by age (R² = 0.06) and immunomodulatory treatment (R² = 0.02).

“EDSS and age were independent risk factors of severe COVID-19, while exposure to immunomodulatory DMTs (interferon and glatiramer acetate) were independently associated with lower COVID-19 severity. We did not find an association between other [DMT] exposure (including immunosuppressive therapies) and COVID-19 severity,” the researchers wrote. “The identification of these risk factors should provide the rationale for an individual strategy regarding clinical management of MS patients during the COVID-19 pandemic.”