Outcomes of COVID-19 re-infections: a single-center cohort of 167 patients with systemic rheumatic diseases.

Data on COVID-19 re-infections in patients with systemic rheumatic diseases (SRDs) are lacking. We aimed to describe the course and outcomes of COVID-19 re-infections in these patients versus controls. In this single-center retrospective study, we included 167 consecutive SRD patients with at least one COVID-19 re-infection (mean age 47.3 years, females 70.7%). SRD patients were compared in terms of patient-perceived COVID-19 re-infection severity and hospitalizations/deaths with 167 age/sex-matched non-SRD controls. Logistic regression analysis was performed to assess potential milder re-infection versus primary infection severity, adjusting for study group, demographics (age, sex), vaccination status, body mass index, smoking, and comorbidities. 23 and 7 out of 167 re-infected SRD patients experienced two and three re-infections, respectively, which were comparable to the re-infection rates in controls (two: 32; and three: 2) who also had comparable COVID-19 vaccination history (89% and 95% vaccinated, respectively). In the initial infection, patients with SRDs were hospitalized (7.2% versus 1.8%, p = 0.017), and had received antiviral treatment (16.1% versus 4.7%, p < 0.001) more frequently than controls. However, hospitalizations (1.8% vs 0.6%) and antiviral treatment (7.8% vs 3.5%) did not differ (p > 0.05) between patients and controls at the first re-infection, as well as during the second and third re-infection; no deaths were recorded. Perceived severity of re-infections was also comparable between patients and controls (p = 0.847) and among those on biologic DMARDs or not (p = 0.482). In multivariable analysis, neither SRDs presence nor demographics or comorbidities were associated with COVID-19 re-infection severity. COVID-19 re-infection severity (patient-perceived/hospitalizations/deaths) did not differ between SRDs and controls.