Thrombotic thrombocytopenic purpura: the systemic clumping "plague".

摘要: In thrombotic thrombocytopenic purpura (TTP), a multimeric form of von Willebrand factor (vWf) that is larger than ordinarily found in the plasma causes systemic platelet aggregation under high-shear conditions microcirculation. A divalent cation-activated, vWf-cleaving metalloprotease metabolizes large vWf multimers to smaller forms normal severely reduced or absent most patients with TTP. The either not produced defective children chronic relapsing When enzyme provided by infusion plasma, these remain free TTP symptoms for about three weeks. An IgG autoantibody transiently many adult acute idiopathic, recurrent, and ticlopidine/clopidogrel-associated These require exchange, i.e., concurrent replacement inhibited plasmapheresis. present fresh-frozen cryoprecipitate-depleted (cryosupernatant), has been treated solvent detergent. pathophysiology bone marrow transplantation/chemotherapy-associated microangiopathy, hemolytic-uremic syndrome, established. neither condition there severe decrease activity.