A specific molecular signature in SARS-CoV-2 infected kidney biopsies

International audienceAcute kidney injury (AKI) is one of the most important complications in COVID-19 patients and is considered a negativeprognostic factor with respect to patient survival. The occurrence of direct infection of the kidney by SARS-CoV-2, and itscontribution to the renal deterioration process, remains a controversial issue. By studying 32 renal biopsies from COVID-19 patients we confirmed that the major pathological feature of COVID-19 is acute tubular injury (ATI). Using smFISH, weshowed that the SARS-CoV-2 infects living renal cells and that infection, which parallels renal ACE2 expression levels, isassociated to increase death. Mechanistically, a transcriptomic analysis uncovered specific molecular signatures inSARS-CoV-2 infected kidneys as compared to healthy kidneys and non-COVID-19 ATI kidneys. On the other hand, wedemonstrated that SARS-CoV-2 and Hantavirus, two RNA viruses, activated different genetic networks despite theytriggered the same pathological lesions. Finally, we identified XAF1 as a critical target of SARS-CoV-2 infection. Inconclusion, this study demonstrates that SARS-CoV2 can directly infect living renal cells and identified specific druggablemolecular targets that can potentially aid in the design of novel therapeutic strategies to preserve renal function inseverely affected COVID-19 patients

Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients

International audienceThe aim of this study was to estimate the incidence of COVID-19 disease in the French national population of dialysis patients, their course of illness and to identify the risk factors associated with mortality. Our study included all patients on dialysis recorded in the French REIN Registry in April 2020. Clinical characteristics at last follow-up and the evolution of COVID-19 illness severity over time were recorded for diagnosed cases (either suspicious clinical symptoms, characteristic signs on the chest scan or a positive reverse transcription polymerase chain reaction) for SARS-CoV-2. A total of 1,621 infected patients were reported on the REIN registry from March 16th, 2020 to May 4th, 2020. Of these, 344 died. The prevalence of COVID-19 patients varied from less than 1% to 10% between regions. The probability of being a case was higher in males, patients with diabetes, those in need of assistance for transfer or treated at a self-care unit. Dialysis at home was associated with a lower probability of being infected as was being a smoker, a former smoker, having an active malignancy, or peripheral vascular disease. Mortality in diagnosed cases (21%) was associated with the same causes as in the general population. Higher age, hypoalbuminemia and the presence of an ischemic heart disease were statistically independently associated with a higher risk of death. Being treated at a selfcare unit was associated with a lower risk. Thus, our study showed a relatively low frequency of COVID-19 among dialysis patients contrary to what might have been assumed