[Red cell fragmentation and hemolysis in thrombotic thrombocytopenic purpura (TTP)]

Thrombotic thrombocytopenic purpura (TTP) is an uncommon, life-threatening disorder associated with multiple causes and occurring mainly in adults with multiorgan microvascular thrombosis. The high mortality of this disease needs rapid diagnosis and immediate therapy including plasmapheresis, plasma infusions, corticosteroids and immunosuppressive therapy, which have been improved survival rates of this disorder. Red cell fragmentation due to microangiopathic hemolytic anemia (MAHA) is one of the most characteristic findings in TTP. Identification of red cell fragments and hemolysis is, therefore, important for its rapid diagnosis. It is thought that hemolytic anemia is a consequence of mechanical damage to erythrocytes by fibrin strands, as they traverse peripheral microvessels. However, little is known of the mechanisms of red cell fragmentation and its relation to pathogenesis of TTP. We reviewed red cell deformity and its association to hemolysis by the points of physiologic, chemical and clinical aspects of erythrocytes.