Oneliner_2280

OneLiner

TTP is a disease characterized by deficiency of the von Willebrand factor (vWF) metalloprotease, called ADAMTS13, an enzyme that normally degrades very large multimers of vWF. In its absence, these multimers accumulate in plasma and can promote platelet adhesion throughout the circulation. The formation of platelet aggregates leads to thrombocytopenia. However, because the coagulation cascade is not involved, results of coagulation tests such as prothrombin time and partial thromboplastin time are normal. Common causes include drug therapy, HIV, pregnancy, and familial factors, although TTP may also be idiopathic.