Unvaccinated patients with systemic autoimmune rheumatic diseases have heterogeneous and unrelated risks of covid infection and poor outcome

Abstract Background : The impact of the severe acute respiratory syndrome Coronavirus 2 disease (COVID-19) pandemic on people with systemic autoimmune rheumatic diseases (SARDs) is not fully established. It is unclear whether SARDs are an independent risk factor for infection and poor outcomes. Methods : Incidence and 30-day outcomes of COVID-19 infection were retrospectively evaluated in 40,490 SARD patients in the Lazio Italian Region and compared to the general population as incidence rate ratio adjusted for demographics and comorbidities (adjIRR). SARD diagnosis and comorbidities were derived from medical administrative records using the Chronic Related Group classification system. Data on COVID-19 infection were derived from a dedicated regional digital network. Results : The COVID-19 infection risk was increased in patients with Psoriatic Arthritis (adjIRR=1.21, 95% CI 1.10-1.33) and Undifferentiated Connective Tissue Disease (adjIRR=1.26, 95% CI 1.03-1.54). The hospitalization risk was higher in patients with Axial Spondylarthritis (adjIRR=2.16, 95% CI 1.45-3.22), and Systemic Vasculitis (adjIRR=1.81, 95% CI 1.07-3.06) while intensive care unit admission risk was higher in Systemic Erythematosus Lupus (adjIRR=3.67, 95% CI 1.52-8.83) and primary Sjögren Syndrome (adjIRR=4.13, 95% CI 1.71-9.96) patients. Increased mortality was reported in patients with Rheumatoid Arthritis (adjIRR=1.50, 95% CI 1.04-2.17), Systemic Erythematosus Lupus (adjIRR=2.67, 95% CI 1.10-6.44), primary Sjögren Syndrome (adjIRR=2.51, 95% CI 1.12-5.62), and Scleroderma (adjIRR=4.60, 95% CI 2.06-10.29). Conclusions : Each SARDs presents a peculiar pattern in terms of increased risk of COVID-19 incidence, hospitalization, intensive care unit admission, and death, that is not linked to the immunosuppressive behaviour of the disease.