Susceptibility and severity of COVID-19 in patients treated with bDMARDS and tsDMARDs: a population-based study

Patients with autoimmune conditions treated with biological agents have an increased risk of severe infections.1 2 Very few studies have evaluated the susceptibility and severity of coronavirus disease 2019 (COVID-19) in patients treated with biological disease-modifying antirheumatic drugs (bDMARDs) or targeted synthetic DMARDs (tsDMARDs).3 4 Some of these studies suggest a protective role of these drugs for COVID-19; however, they consist of small series, and the results are unclear. Therefore, we decided to evaluate in a population-based study the risk of COVID-19 infection and its severity in the patients treated with bDMARDs or tsDMARDs in a geographic area (Emilia Romagna) at high diffusion of COVID-19. We identified 1195 patients treated with the bDMARDs or tsDMARDs listed in table 1 in Reggio Emilia area on 31 December 2019. Biological agents were classified according to the mechanism of action. The patients were registered in the database of the Hospital Pharmaceutical Service of the Reggio Emilia area, which delivers the drug directly to the patients. The database is updated every 3 months. All residents …