The use of immunosuppressive therapy (IST) in patients with myasthenia gravis (MG) does not appear to raise the risk of acquiring a SARS-CoV-2 infection, but may increase the risk of having a more serious infection, according to a study published in the Journal of Neurology.

During the study, 76 out of 1164 patients with MG (6.5%) who were being treated with IST acquired SARS-CoV-2 infections compared to 19 out of 221 patients with MG (8.6%) who were treated without IST. After propensity matching, 5.1% of the IST group became infected compared to 7.9% of those without IST. A total of 11 patients died.

Using a multivariable binary logistic regression model for the nonmatched groups and a generalized estimation equation model for the matched groups both showed no substantial association between IST and the risk of becoming infected with SARS-CoV-2.

Read more about MG therapies

Of the 95 patients who were affected by COVID-19, 32 (34%) required hospitalization, with 12 (13%) being admitted to the ICU.

When comparing patients with MG who were hospitalized or deceased with patients who were not hospitalized, those who had more serious infections tended to be older (68 years vs 53 years; standardized mean difference (SMD, .94), more often male (56% vs 33%; SMD, .47), have a higher Myasthenia Gravis Foundation of America classification score (SMD, .83), or more frequently receiving MG-related IST (84.4% vs 77.8%; SMD, .48), and had a higher prevalence of comorbidities (88% vs 73%; SMD, .37).

Multivariable binary logistic regression adjusted for age, sex, and comorbidities found that patients receiving first-line IST or escalation therapy with rituximab had a higher risk of hospitalization or death compared to those not receiving IST or only receiving corticosteroids (OR, 3.04; 95% CI, 1.02–9.06; P =.046). All deceased patients had at least 1 concomitant disease in addition to MG, and 9 of the 11 were receiving IST at the time of infection.

“This registry-based cohort study suggests that the current use of IST does not increase the risk of SARS-CoV-2 infection per se but, together with older age, worsens the prognosis of COVID-19-affected patients with MG,” the authors said.

Reference

Stascheit F, Grittner U, Hoffmann S, et al. Risk and course of COVID-19 in immunosuppressed patients with myasthenia gravis. J Neurol. Published online September 27, 2022. doi:10.1007/s00415-022-11389-0