title: [Thrombotic microangiopathies].
abstract: Thrombotic microangiopathies (TMA) encompass various diseases characterized by a microangiopathic hemolytic anemia, platelet clumping, and organ failure of variable severity. Thrombotic thrombocytopenic purpura (TTP) is a particularly severe form of TMA characterized by systemic organ failure which results from a severe defect in ADAMTS13, a plasma enzyme specifically involved in the cleavage of highly hemostatic unusually large (UL) von Willebrand factor (VWF) multimers into smaller and less adhesive VWF forms. Failure to degrade these UL-VWF multimers leads to excessive platelet aggregates and capillary occlusion. Hemolytic uremic syndrome (HUS) is characterized prominently by a renal failure. In most cases, HUS is caused by entero-hemorrhagic Escherichia coli strains which secrete a shiga-like toxin (STX). STX-negative HUS, termed atypical HUS, was associated with a dysfunction in complement pathway. The major improvement in our understanding of TMA pathophysiology allows now a more accurate molecular classification of TMA syndromes, which opens fascinating perspectives of targeted therapies.
authors.affiliation: Centre de référence des microangiopathies thrombotiques, Département d'hématologie, Hôpital Saint-Antoine, UPMC (Université Paris-VI), 75012 Paris, France.
authors.forename: Constance
authors.initials: C
authors.lastname: Moulinier
authors.forename: Agnès
authors.initials: A
authors.lastname: Veyradier
authors.forename: Eric
authors.initials: E
authors.lastname: Rondeau
authors.forename: Paul
authors.initials: P
authors.lastname: Coppo
mesh_terms: D000465:Algorithms; D003937:Diagnosis, Differential; D018450:Disease Progression; D006463:Hemolytic-Uremic Syndrome / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000628:therapy; D006801:Humans; D008954:Models, Biological; D011320:Primary Health Care / Q000379:methods; D011379:Prognosis; D057049:Thrombotic Microangiopathies / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000628:therapy