The 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.

Reactive hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition related to a cytokine storm leading to multiorgan dysfunction. A better understanding of coagulation disorders, frequently reported in HLH patients, may improve outcomes.Critically ill HLH patients managed in a multidisciplinary national reference center were retrospectively included. Relationships between coagulation disorders, severe bleedings, and outcomes were assessed.One hundred and seventeen patients fulfilled the HLH 2004 criteria. The most common HLH etiology was hematologic conditions (73%), followed by infectious diseases (20%), systemic rheumatic diseases (5%), and undetermined HLH etiology (3%). All patients exerted thrombocytopenia. Coagulation disorders were diagnosed in 79 (68%) patients (61 had hypofibrinogenemia < 1.5 g/L, 51 had prothrombin time [PT] < 50%). The worst median value throughout ICU stay was 52% (38–65) for PT with a factor V level of 35% (27–43), 1.59 (1.30–2.09) for the activated partial thromboplastin time (APTT) ratio, and 2.33 g/L (1.13–3.86) for the fibrinogen level. Disseminated intravascular coagulation (DIC) was found in 50% of patients. Coagulation disorders were more frequent in immunocompromised patients, those with histological/cytological feature of hemophagocytosis, those with the highest ferritin concentrations, and in patients with HLH not related to infection. These patients were more prone to receive mechanical ventilation, vasopressors, or renal replacement therapy. Twenty-six (22%) patients presented severe bleeding complications, including 5 patients dying from hemorrhagic shock. Strikingly, the only coagulation parameter significantly associated with severe bleeding was low fibrinogen with a cutoff value of 2 g/L (P = 0.03). Overall, 33 (28%) patients died in the ICU and hospital mortality was 44%. Coagulation disorders were associated with higher mortality, especially fibrinogen < 2 g/L (P = 0.04) and PT value (P = 0.03). The occurrence of bleeding complications was not associated with higher risk of hospital death. Risk factors associated with mortality by multivariate analysis were fibrinogen level < 2 g/L (OR 2.42 [1.08–5.41]), SOFA score > 6 (OR 3.04 [1.32–6.98]), and age > 46 years (OR 2.26 [1.02–5.04]).Up to two-third of critically ill HLH patients present with coagulation disorders. Hypofibrinogenemia or DIC was found in half of the patients and low PT in 40%. These patients require more life support and have a higher mortality rate. Fibrinogen <2 g/L is associated with the occurrence of severe bleeding and mortality.