Assessment of patients with thrombotic thrombocytopenic purpura

Abstract. Thrombotic thrombocytopenic purpura (TTP) is a severe microvascular occlusive thrombotic microangiopathy characterized by systemic platelet aggregation, organ ischemia, profound thrombocytopenia, and fragmentation of erythrocytes. Unexplained occurrence of thrombocytopenia and anemia should prompt immediate consideration of the diagnosis and evaluation of peripheral blood smear for evidence microangiopathic hemolytic anemia. Excellent remission and survival rates were achieved by therapeutic plasma exchange. We reviewed characteristics and response rates to plasmapheresis of our TTP patients. A total of 25 cases were diagnosed. The parameters of hemoglobin and platelet were analyzed at presentation, as well as the number of plasmapheresis sessions and adjunctive treatment given. We found a response rate of 80 percent to plasma exchange. Response was better in 23 patients who presented with idiopathic TTP. Response was poor in patients with TTP secondary to underlying metastatic carcinoma. Two patients relapsed and one of the relapsed patients died. Plasmapheresis is mandatory and effective for primary TTP. Plasmapheresis may not be effective in all instances, especially if TTP is secondary to underlying disseminated cancer. Key words: Thrombotic thrombocytopenic purpura, therapeutic plasmapheresis