Systemic lupus erythematosus and COVID-19: what we know so far.

We read with interest the recent report by Mathian et al 1 about 17 patients with systemic lupus erythematosus (SLE) and COVID-19, which has paved the way to a constellation of articles aiming to find clues on potential peculiarities in COVID-19 epidemiology and course among patients with SLE. An ongoing debate has also recently grown on the role of hydroxychloroquine (HCQ), with increasing data disconfirming a protective effect of this drug towards severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in general and specifically also in patients with SLE.2 3 We were thus prompted to summarise the evidence published so far on this latter topic to look for recurrent clinical or epidemiological patterns among different studies/cohorts. To this aim, we analysed all studies published in the English literature until June, 30th 2020 and identified 20 articles describing a total of 4059 patients with SLE, 255 of whom with a PCR-confirmed or presumptive (ie, based on symptoms or radiological findings) diagnosis of …