[Vascular endothelial cell injury as the initial event in thrombotic thrombocytopenic purpura]

It is an important argument whether vascular endothelial injury is the initial event or not in TTP. There is many possible triggers to vascular endothelial injury: Endotoxins, immune complex, and drugs et al. In these conditions, some cytokines (TNF, IL-1 etc.) induce the activation of endothelial cell. Then, neutrophil can adhere to endothelial cells through adhesion molecules. Endothelial cells were injured, by the activation and the adhesion of neutrophil. The injury of the endothelial cells causes the exposure of subendothelial tissues, and then induce the platelet adhesion on these surface for the initial event of platelet aggregates. Although heterogenous triggers and pathophisiological events are recognized in TTP, endothelial cell injury is the initial event or the essential event.