[Recent data on atypical hemolytic uremic syndrome associated with pregnancy, kidney transplantation or hypertensive emergency].

Thrombotic microangiopathies (TMA) are a heterogeneous group of disorders characterized to varying degrees by mechanical hemolytic anemia, thrombocytopenia and histological microvascular occlusion. TMA can be complicated by multiple organ disorders, mainly neurological and nephrological (defining the hemolytic uremic syndrome, HUS). Classification based on disease pathophysiology has highlighted the importance of dysregulation of the alternative complement pathway in atypical (non-infection-related) HUS. However, the pathophysiology and treatment of many forms of aHUS in specific contexts (such as pregnancy, renal transplantation or hypertensive emergencies) remain poorly characterized. In this article, we review recent diagnostic and therapeutic advances in these three forms of aHUS in specific contexts. We show the specificities of these forms and describe the current and future challenges of their management.