Moschcowitz syndrome or thrombotic thrombocytopenic purpura is a rare disorder 
with a poor prognosis. This syndrome is characterized by a microangiopathic 
hemolytic anemia with thrombocytopenia, neurologic symptoms and renal disease. 
The vascular lesion consists of disseminated hyaline thrombi in the 
microvasculature composed mainly of platelet aggregates. The mechanisms are 
still poorly understood and are probably multiple. Recent data focus on an 
abnormal endothelial synthesis of prostacyclin and the presence of a factor (or 
the reduction of its inhibitor) in plasma able to induce intravascular 
disseminated platelet aggregation. The most efficient therapy seems to be 
infusions of fresh plasma with or without plasma exchange.