Prevalence of COVID-19 in patients with rheumatoid arthritis (RA) already treated with hydroxychloroquine (HCQ) compared with HCQ-naive patients with RA: a multicentre cross-sectional study

COVID-19 is becoming the most serious problem of human society after World War II. The general recommendations of WHO, which include wearing mask, social distancing, washing hands and so on, are a widely accepted approach to preventing the spread of the virus. With lack of effective treatment, prophylactic strategies have attracted the attention of healthcare providers. Chemoprophylaxis is one of these strategies. Several in vitro studies showed that antimalarial agents interfere with the proliferation of various viruses, including the severe acute respiratory syndrome coronavirus, by inhibiting virus/cell fusion.1 However, the main challenge is translating the impact of in vitro models to clinics. Given the higher mortality of patients with COVID-19 with autoimmune diseases,2 we decided to investigate the efficacy of these medications by evaluating the incidence of COVID-19 in patients with rheumatoid arthritis (RA) already treated with hydroxychloroquine (HCQ) compared with HCQ-naive patients with RA.\n\nIn a multicentre cross-sectional study, patients with RA treated in the rheumatology clinics of the Tabriz University of Medical Sciences, Kashan University of Medical Sciences and Army Hospital of Tehran were recruited. For a period of 4 weeks from 19 August to 19 September 2020, data about symptoms suggestive of COVID-19 were obtained by telephone interview. Inclusion criteria were fulfilment of the American …