[Case of thrombotic thrombocytopenic purpura with a positive Coomb test].

We report a case of thrombotic thrombocytopenic purpura (TTP) with a positive Coombs' test. A 59-year-old female was admitted to our hospital in February, 1997 with symptoms of heart failure. Ultrasound cardiography showed moderate pericardiac effusion and she was diagnosed as having pericarditis. After admission she had anorexia and her urine volume was reduced. Laboratory tests showed anemia and thrombocytopenia. Her Coombs' test result was positive. Her renal function gradually worsened and her conscious level was reduced. We diagnosed her as TTP and judged that she needed hemodialysis. We performed plasma exchange and started steroid therapy. The renal biopsy was compatible with TTP. After treatment, her level of consciousness improved, but her renal function did not improve. On the 51st hospital day she fell into acute respiratory distress syndrome (ARDS) and entered ICU. We considered ARDS caused by infection and continued treatment, but she died of shock and lactate acidosis. Activity of von Willebrand factor-cleaving protease in our case was 15% before the first PE, and 25 % just before death. A case of TTP without collagen disease usually shows a negative Coombs' test result. We think that this was a rare case in which autoimmune hemolytic anemia was supervened with TTP.