Effect of Immunosuppressive or Immunomodulatory Agents on Severe COVID-19 Outcomes: A Population-Based Cohort Study

We estimated the association between immunosuppressive and immunomodulatory agent (IIA) exposure and severe COVID-19 outcomes in a population-based cohort study.

Participants were 18 years or older, tested positive for SARS-CoV-2 between February 6, 2020, and August 15, 2021, and were from administrative health data for the entire province of British Columbia, Canada. IIA use within 3 months prior to positive SARS-CoV-2 test included conventional disease-modifying antirheumatic drugs (antimalarials, methotrexate, leflunomide, sulfasalazine, individually), immunosuppressants (azathioprine, mycophenolate mofetil/mycophenolate sodium [MMF], cyclophosphamide, cyclosporine, individually and collectively), tumor necrosis factor inhibitor (TNFi) biologics (adalimumab, certolizumab, etanercept, golimumab, infliximab, collectively), non-TNFi biologics or targeted synthetic disease-modifying antirheumatic drugs (tsDMARDs) (rituximab separately from abatacept, anakinra, secukinumab, tocilizumab, tofacitinib and ustekinumab collectively), and glucocorticoids. Severe COVID-19 outcomes were hospitalizations for COVID-19, ICU admissions, and deaths within 60 days of a positive test. Exposure score-overlap weighting was used to balance baseline characteristics of participants with IIA use compared with nonuse of that IIA. Logistic regression measured the association between IIA use and severe COVID-19 outcomes.

From 147,301 participants, we identified 515 antimalarial, 573 methotrexate, 72 leflunomide, 180 sulfasalazine, 468 immunosuppressant, 378 TNFi biologic, 49 rituximab, 144 other non-TNFi biologic or tsDMARD, and 1348 glucocorticoid prescriptions. Risk of hospitalizations for COVID-19 was significantly greater for MMF (odds ratio [95% CI]): 2.82 [1.81-4.40], all immunosuppressants: 2.08 [1.51-2.87], and glucocorticoids: 1.63 [1.36-1.96], relative to nonuse. Similar outcomes were seen for ICU admission and MMF: 2.52 [1.34-4.74], immunosuppressants: 2.88 [1.73-4.78], and glucocorticoids: 1.86 [1.37-2.54]. Only glucocorticoids use was associated with a significant increase in 60-day mortality: 1.58 [1.21-2.06]. No other IIAs displayed statistically significant associations with severe COVID-19 outcomes.

Current use of MMF and glucocorticoids were associated with an increased risk of severe COVID-19 outcomes compared with nonuse. These results emphasize the variety of circumstances of patients taking IIAs.