Outcome of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome in Japan

We examined 159 patients with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome in Japan. The subjects were divided in three groups; 90 patients with thrombotic thrombocytopenic purpura, 51 patients with verotoxin-induced hemolytic uremic syndrome, and 18 patients with drug-induced hemolytic uremic syndrome. Eighty-two percent of the patients with thrombotic thrombocytopenic purpura had associated neurological disorders and 78% of drug-induced hemolytic uremic syndrome associated with pulmonary edema. Renal insufficiency was noted in the 69% cases with both hemolytic uremic syndrome groups. Seventeen patients with thrombotic thrombocytopenic purpura had systemic lupus erythematosus and 6 were pregnant. Autoantibody were positive in 53% of thrombotic thrombocytopenic purpura. Seventy-seven percent of patients with thrombotic thrombocytopenic purpura received plasma exchange at 4,000 mL/day three times a week, 71% antithrombotic agents, and 78% steroid administration, respectively. However, 27% of the patients with hemolytic uremic syndrome were treated by hemodialysis in addition to antithrombotic agents. When drug-induced hemolytic uremic syndrome was diagnosed, the drug was immediately discontinued and the patients were treated with antiplatelet agents. Seventy-four percent of the patients with thrombotic thrombocytopenic purpura were alive at 26 weeks compared with 95% of those with hemolytic uremic syndrome. As thrombotic thrombocytopenic purpura had a high mortality rate in Japan, we should carry out early diagnosis and early treatment.