RSV Poses Significant Threat to Patients With Systemic Autoimmune Rheumatic Diseases

A retrospective cohort study from Massachusetts General Hospital has found that respiratory syncytial virus (RSV) infections are associated with substantial morbidity among patients with systemic autoimmune rheumatic diseases (SARDs), with more than half of infected individuals requiring hospitalization. The findings underscore the vulnerability of this population—particularly those who are frail, have multiple comorbidities, or are receiving certain immunomodulatory treatments—during periods of RSV circulation.

Between 2015 and 2023, researchers identified 188 individuals with both SARDs and confirmed RSV infection. The mean patient age was 68.5 years, and 75.5% were female. Among these patients, 96 (51.0%) were hospitalized following infection. Of those hospitalized, over half (56%) required supplemental oxygen, and 12 deaths occurred within 90 days, representing 12.5% of hospitalized patients and 6% of the entire RSV-positive cohort. Importantly, the research was conducted before RSV vaccination became widely available, suggesting the data reflect unmitigated infection outcomes.

Multivariable logistic regression analysis identified several predictors of hospitalization in this cohort. A higher Charlson Comorbidity Index was associated with increased odds of hospitalization (adjusted odds ratio [aOR] 1.16 per point; 95% CI, 1.04-1.31), indicating that each incremental comorbidity raised the likelihood of severe disease. Similarly, frailty was strongly associated with hospitalization risk. Individuals categorized as frail had nearly 5 times the odds of hospitalization compared with those who were robust or pre-frail (aOR 4.80; 95% CI, 2.32-9.94).

Concurrent infections at the time of RSV diagnosis were another significant risk factor, associated with more than double the odds of hospitalization (aOR 2.52; 95% CI, 1.07-5.92). Additionally, treatment with CD20 inhibitors—such as rituximab—was linked to numerically higher hospitalization risk (aOR 3.84 vs conventional synthetic DMARDs; 95% CI, 0.99-15.20). Age also contributed modestly to risk, with a 3% increase in odds per additional year (OR, 1.03 per year; 95% CI, 1.01-1.05).

For pharmacists involved in rheumatology or infectious disease care, these findings emphasize the need for heightened vigilance during RSV season, especially among older or medically complex patients. Frailty assessment and comorbidity review may help identify individuals at greatest risk for poor outcomes. Moreover, patients receiving CD20 inhibitors may warrant particular attention, as these agents deplete B cells and can impair antiviral immune responses.

The data also reinforce the potential value of preventive measures, including vaccination and infection control strategies, once vaccines are accessible to this population. Pharmacists should be prepared to support clinicians in identifying eligible patients for RSV vaccination and provide counseling regarding timing in relation to immunosuppressive therapy.

Reference

Enns JP, Wang J, Jiang B, et al. Outcomes of respiratory syncytial virus infection in patients with systemic autoimmune rheumatic disease. Semin Arthritis Rheum. 2025;75:152846. doi:10.1016/j.semarthrit.2025.152846