MG raises severe COVID-19 risk, but vaccination helps reduce risk

people with myasthenia gravis People with (MG) COVID-19 are at higher risk of hospitalization, but new research suggests they may benefit from vaccination in a similar way to the general population.

The report was announced in JAMA network openbelieved to be the largest study of its kind since the beginning of the COVID-19 era.

Lead author Carolina Barnett, M.D., of Toronto General Hospital, writes that people with chronic conditions like MG are thought to be at increased risk of severe COVID-19 because of their immunosuppressive state. However, there are relatively few studies on how the infection affects MG patients, they said.

In a new study, Barnett and the authors utilized the Ontario, Canada administrative database to identify patients with MG, matched controls from the general population, and a second set of controls consisting of patients with rheumatoid arthritis (RA). We identified the cohort.

“Because of limited administrative data on medications, we also matched against a cohort of patients with rheumatoid arthritis (RA) to describe potential associations between immunosuppressive treatment and COVID-19 outcomes,” they wrote. explained.

From a total pool of over 11 million people, 4,411 were found to have MG, matching them to 22,055 in the general population and 22,055 in RA. The mean age of all three cohorts was her 66.7 years, all slightly majority females. Nearly 9 of her 10 residents of each cohort lived in urban areas.

Between 15 January 2020 and 17 May 2021, investigators found that 164 MG patients (3.7%) tested positive for polymerase chain reaction COVID-19. This compares with 669 in the general population cohort and 668 in the RA cohort (3.0% of his in both cohorts).

However, once infected, data confirm that MG patients are at increased risk of severe illness. , 24.4% in the general population and 29.9% in the RA cohort.

Hospitalization was also more common in the MG group (30.5%) than in the general population cohort (15.1%) or the RA cohort (20.7%). Finally, her 30-day mortality in MG patients (14.6%) was higher than those in the general population (8.5%) or RA patients (9.9%).

Barnett et al. pointed out that one of the reasons for the higher rate of severe disease compared to the general population may be the higher prevalence of comorbidities in the MG group. “However, patients with MG also have an increased risk of severe COVID-19 outcomes compared with controls with RA, who have well-balanced comorbidities and immunosuppression is common, and are associated with these worse outcomes.” suggesting that there may be factors unique to MG,” they wrote.

The good news, according to Burnett and colleagues, is that vaccines appear to significantly reduce the risk of hospitalization. Of his 80.3% of MG patients, he had received two doses of the vaccine by August 2021, and another 3.1% of him had received one dose. Vaccination coverage in the general population cohort was similar.

Researchers found that vaccinated MG patients had a lower risk of contracting COVID-19 compared to unvaccinated patients (HR, 0.43; 95% CI, 0.30 -0.60). Indeed, they noted that the benefit of vaccination appeared to be somewhat higher in the MG group than in the control group (HR 0.70; 95% CI, 0.57-0.84).

While some fear the vaccine could lead to MG relapse, Barnett and colleagues found that hospitalizations within 30 days after vaccination were “negligible” and that “the vaccine is safe from an MG perspective.” It suggests that,” he said.

Overall, investigators said their data show that MG poses a severe risk of COVID-19 to patients, but that such risk can also be mitigated by vaccination.

“Our results support prioritization of MG patients for vaccination and consideration of early COVID-19 treatments such as antiviral drugs and monoclonal antibodies,” they concluded. .

reference

Alcantara M, Koh M, Park A, etc. Outcomes of his COVID-19 infection and vaccination in a patient with myasthenia gravis. JAMA net opened. 2023;6(4):e239834.doi:10.1001/jamanetworkopen.2023.9834