TY - JOUR T1 - Correspondence on ‘Clinical course of coronavirus disease 2019 (COVID-19) in a series of 17 patients with systemic lupus under long-term treatment with hydroxychloroquine’ JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - e33 LP - e33 DO - 10.1136/annrheumdis-2020-217827 VL - 80 IS - 3 AU - Mandana Nikpour AU - Benjamin Teh AU - Ian P Wicks AU - Marc Pellegrini Y1 - 2021/03/01 UR - http://ard.bmj.com/content/80/3/e33.abstract N2 - We thank Mathian et al for reporting the outcomes of COVID-19 disease in a series of 17 patients with systemic lupus erythematosus (SLE) from several hospitals across France.1 In a context where there is substantial interest in the role of hydroxychloroquine (HCQ) as a potential preventive or therapeutic agent for severe acute respiratory syndrome–coronavirus-2 (SARS-CoV-2), these cases are noteworthy.While the authors have correctly acknowledged the limitations of this case series report, we wish to emphasise several important points that impact the interpretation of the findings. The denominator of all patients with lupus on hydroxychloroquine who are ‘at risk’ of COVID-19 in this setting is unknown and may indeed be impossible to even estimate as it would need to … ER -