The current outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease 2019 (COVID-19) represents a source of concern for the management of patients with systemic lupus erythematosus (SLE). Indeed patients with SLE have an increased risk of severe infections due to intrinsic perturbations of their immune response, the use of immunosuppressive drugs, as well as the potential presence of organ damage associated with their disease. In this context, hydroxychloroquine (HCQ), a drug that is currently part of the long-term, standard-of-care treatment for SLE, has been reported to possess antiviral activity in vitro, and recent results from a preliminary clinical trial might support its use in curative or even prophylactic treatment for COVID-19. 1–3

During the first days of the COVID-19 outbreak in France, we launched an observational study with the aim to follow the clinical course of COVID-19 in patients with SLE who received long-term treatment with HCQ. To be eligible, patients with SLE had to (1) fulfil the 1997 criteria of the SLE classifications of the American College of Rheumatology or those of the 2019 European League Against Rheumatism/American College of Rheumatology 4 5;(2) be on long-term treatment with HCQ; and (3) have SARS-CoV-2 carriage in their nasopharyngeal swab, as confirmed by real-time reverse transcription PCR analysis. Data were collected from 17 patients with SLE between 29 March and 6 April (tables 1 and 2). The initial symptoms of the first patient appeared on 5 March and those of the last patient on 26 March. The main comorbidities were obesity and chronic kidney disease, which were present in 10 (59%) and 8 (47%) patients, respectively. All patients except one had clinically quiescent SLE, defined as a clinical Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score equal to 0. 6 The duration of HCQ treatment prior to COVID-19 was relatively long, with a median (range) of 7.5 (0.5–29.8) years. Twelve (71%) patients were also treated with prednisone, at doses usually below 10 mg per day, and seven (41%) with an immunosuppressant. Except for a higher rate of dyspnoea, headache and diarrhoea, clinical signs and symptoms of COVID-19 were similar to those described previously. 7 8