AMID the summer COVID surge, adult systemic autoimmune rheumatic disease patients exhibit prolonged SARS-CoV-2 antigen persistence. A retrospective multicohort analysis evaluating post-acute viral dynamics revealed that individuals with systemic autoimmune rheumatic diseases maintain circulating viral antigens in peripheral blood significantly longer than the general population. Using ultrasensitive digital single-molecule array assays, investigators detected viral targets up to six months after initial infection, pointing to delayed viral clearance and possible ongoing viral reservoirs in immunocompromised hosts.
Overall, any circulating viral antigen was detected in 36.7% of systemic autoimmune rheumatic disease patients compared to 18.9% of controls without autoimmune conditions at blood collection. When evaluating specific targets three months post-infection, systemic autoimmune rheumatic disease patients demonstrated significantly greater odds of overall antigen positivity (adjusted odds ratio: 2.89; 95% confidence interval: 1.43 to 5.85). This marked discrepancy remained consistent after multivariable adjustment for age, sex, calendar year of infection, vaccination status, and receipt of acute COVID-19 therapies.
Persistent nucleocapsid antigen positivity served as the primary driver of these long-term differences between cohorts. Because nucleocapsid reflects viral replication rather than vaccine-induced immunity, its retention signals prolonged viral shedding. At three months, systemic autoimmune rheumatic disease patients had 3.73-fold higher adjusted odds of circulating nucleocapsid antigen. By month six, the adjusted odds rose to 6.62 (95% confidence interval: 1.09 to 40.30). Notably, the proportion of systemic autoimmune rheumatic disease patients with positive nucleocapsid antigen remained stable between months three and six (18.3% versus 19.4%), whereas control rates declined to 2.5%.
Underlying immune dysregulation and ongoing immunosuppressive therapy likely hinder efficient antigen clearance. Nucleocapsid protein triggers systemic inflammation and proinflammatory cytokine production, which may sustain chronic immune activation. Although exploratory analyses showed that SARS-CoV-2 antigen persistence was not significantly associated with post-acute symptoms within this specific subgroup, clinicians managing vulnerable populations during the current viral surge should remain vigilant regarding delayed clearance and extended systemic viral exposure.
Reference
Patel NJ et al. Differences in SARS-CoV-2 Antigen Persistence in Individuals With Systemic Autoimmune Rheumatic Diseases Compared to the General Population: A RECOVER-Adult Cohort Study. Arthritis Rheumatol. 2026;DOI:10.1002/art.70205.
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