Outcome of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome in Japan

We examined 159 patients with thrombotic thrombocytopenic purpura and hemol ytic uremic syndrome in Japan. The subjects were divided in three groups; 9 0 patients with thrombotic thrombocytopenic purpura, 51 patients with verot oxin-induced hemolytic uremic syndrome, and 18 patients with drug-induced h emolytic uremic syndrome. Eighty-two percent of the patients with thromboti c thrombocytopenic purpura had associated neurological disorders and 78% of drug-induced hemolytic uremic syndrome associated with pulmonary edema. Re nal insufficiency was noted in the 69% cases with both hemolytic uremic syn drome groups. Seventeen patients with thrombotic thrombocytopenic purpura h ad systemic lupus erythematosus and 6 were pregnant. Autoantibody were posi tive in 53% of thrombotic thrombocytopenic purpura. Seventy-seven percent o f patients with thrombotic thrombocytopenic purpura received plasma exchang e at 4,000 mL/day three times a week, 71% antithrombotic agents, and 78% st eroid administration, respectively. However, 27% of the patients with hemol ytic uremic syndrome were treated by hemodialysis in addition to antithromb otic agents. When drug-induced hemolytic uremic syndrome was diagnosed, the drug was immediately discontinued and the patients were treated with antip latelet agents. Seventy-four percent of the patients with thrombotic thromb ocytopenic purpura were alive at 26 weeks compared with 95% of those with h emolytic uremic syndrome. As thrombotic thrombocytopenic purpura had a high mortality rate in Japan, we should carry out early diagnosis and early tre atment.