Coagulation changes associated with the hemolytic uremic syndrome

The hemolytic uremic syndrome (HUS) is characterized by hemolytic anemia, a cute renal failure, and thrombocytopenia, The pathological correlate is thr ombotic microangiopathy of glomerular capillaries and arterioles in the kid neys and almost every other organ. The presence of platelet thrombi without extensive soluble coagulation system activation is a constant feature of H US and thrombotic thrombocytopenic purpura (TTP), Damage to the endothelial cell seems to be a central event in the pathogenesis of HUS and TTP, resul ting in loss of fibrinolytic properties and subsequent thrombotic occlusion of the microvasculature, According to earlier and recent studies, a variet y of hemostatic alterations have been described, Among the many findings, l ow platelet counts, increased von Willebrand's factor (VWF), and normal fib rinogen are almost invariably observed. The dubious long-term outcome, even of postdiarrheal HUS, which is believed to have a more favorable prognosis than HUS of other etiopathogenic origin, necessitates further investigatio n of the pathophysiology of thrombotic microangiopathy and meticulous reeva luation of treatment strategies aimed at interfering with the process of th rombosis early in the disease course, The intention of this article is to h ighlight findings possibly relevant for disease management and to give an o verview of the putative pathomechanisms involved.