Thrombotic Thrombocytopenic Purpura— Coagulation Parameters in Twelve Patients

Twelve patients with thrombotic thrombocytopenic purpura have been studied with emphasis on the changes in blood coagulation and the occurrence of disseminated intravascular coagulation (DIC). No coagulation abnormalities were found in six patients. Minimal abnormalities were present in three patients and major abnormalities compatible with DIC were present in three patients. There was little temporal relationship between the coagulation abnormalities and the clinical pathological course except for the extent of hemolysis. In addition, heparin administration in four patients had no effect on the course of the disease. Intravascular coagulation does not appear to be a primary factor in the pathogenesis of thrombotic thrombocytopenic purpura and the changes suggestive of DIC, when present, may well result from, rather than cause, the hemolytic anemia.