All are true about thrombotic thrombocytopenic purpura except?
Grossly abnormal coagulation test Thrombotic thrombocytopenic purpura (TTP) is characterized by the presence of widespread thrombosisthroughout the microcirculation. The unique characteristic of these thrombi is that they are primarily composed of plateletso with very little. fibrin in it. The consumption of platelet leads to thrombocytopenia and the presence of intravascular thrombi causes microangiopathic hemolytic anemiaQ and widespread organ dysfunction. You must have noticed that TTP and DIC share so many similar features such as 4icrovascular occulsion and microangiopathic hemolytic anemia, But they are pathologically distinct. In TTP Activation of coagulation cascade is not of primary impoance. The thrombi present are essentially platelet thrombi, hence results of laboratory tests of coagulation such as PT and PTT are usually normal. In D.I.C. The main defect is activation of coagulation system there fore PT and PTT are abnormal. Patients with TTP are deficient in an enzyme called ADAMTSB. This enzyme is also known as vWf in etalloprotease. This enzyme normally degrades very high molecular weight multimers of von-Willebrand .factor. In the absence of this enzyme, these multimers of vWF accumulate in plasma and under some circumstances promote platelet macroaggregate.formation throughout the microcirculation leading to symptoms of TTP. Thrombotic thrombocytopenic purpura is a thrombotic microangiopathy. The other disorders which is included in this group include H. U.S. The diseases are characterized by widespread thrombosis in microcirculation. The vessels which are involved are terminal aeriolesQ and capillaries. These vessels have thrombi. The characteristic of this thrombus is that it is primarily a platelet thrombusQ i.e. the thrombi is composed mainly of platelets and von Wilebrand factor with very little fibrin in it. Pathogenesis Patients with TTP are deficient in an enzyme called ADAMTSBQ. (This enzyme is also known as vWf nielalloproteaSe.) This enzyme normally degrades very high molecular weight multimers of von-Willebrand .factor. In the absence of this enzyme, these multimers of vWF accumulate in plasma and under some circumstances promote platelet macroaggregate formation throughout the microcirculation leading to symptoms of TTP. Platelet associated immunoglobulin (IgG) and complement levels are normal in T.T.P.
Micro angiopathic hemolytic anemia
Thrombocytopenia
Normal complement level
Grossly abnormal coagulation tests