Thrombotic thrombocytopenic purpura (Moschcowitz' syndrome)

Background: Thrombotic thrombocytopenic purpura (TTP), in 1924 first described by Moschcowitz, is a clinically heterogeneous syndrome associated with thrombocytopenia, Coombs-negative hemolytic anemia, neurologic changes, renal impairment, and fever. TTP is found after various bacterial or viral infectious diseases, autoimmune diseases and also in association with different drugs. Pathogenesis: After initial endothelial cell injury unusually large von Willebrand factors (VWF) are found in plasma of patients with thrombotic thrombocytopenic purpura. Because of impaired proteolysis these large forms lead to thrombosis of the small vessels. The microangiopathy is followed by mechanical destruction of red cells. In peripheral blood smears these fragmentocytes are important for diagnosis and clinical course. Therapy: The therapy of choice is plasma exchange against fresh frozen plasma, whereupon the mortality could be dramatically reduced in the past decades. In case of treatment resistance to plasma exchange there exists no common treatment schedule. One therapy option is immunosuppressive treatment with corticosteroids and vincristine. In case of chronic relapsing TTP splenectomy should be discussed. In spite of severe thrombocytopenia substitution of thrombocytes is contraindicated.