Implications of SARS-CoV-2 infection for patients with rheumatic disease

We read with great interest the letter by Mathian et al in the Annals of the Rheumatic Diseases . In the letter, the authors reported that hydroxychloroquine (HCQ) did not protect patients with systemic lupus erythematosus (SLE) from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the clinical treatment. We report similar results from our study of treatment of patients with SLE on HCQ. We wish to add supplemental evidence to some of the points not adequately addressed in Mathian et al ’s1 letter. Mathian et al did not report the incidence rate of COVID-19 in patients with SLE. We agree with Mathian et al. that it is not practical to assess the actual incidence rate of SARS-CoV-2 in patients with SLE. However, we observed that during the outbreak, 6 (0.2%) cases had SLE in 3057 patients with COVID-19 who were admitted to Wuhan Huoshenshan Hospital (China). Taking that the prevalence of SLE is approximately 0.05%–0.1% in China, this may suggest that patients with SLE are susceptible to SARS-CoV-2 …