We studied 4 patients with thrombotic thrombocytopenic purpura (TTP) and 4 patients with hemolytic uremic purpura (HUS). One case of TTP occurred during the course of systemic lupus erythematosus (SLE), all cases were positive for anti-nuclear antibody, and two cases were positive for anti-platelet antibody. In one case, the level of platelet-associated IgG was correlated with clinical course and it was speculated that TTP was caused by an autoimmune mechanism. Before the onset of TTP, common cold-like symptoms were seen in 3 patients with HUS. The disseminated intravascular coagulation (DIC) score was high in all patients especially those, with HUS, but typical DIC was not seen in any patients. Microthrombus was detected in 3 patients with TTP, but was not detected in renal biopsy specimens from 2 patients with HUS. All patients showed good response to hemodialysis, steroid, heparin or FOY, but two patients had relapses. TTP patients were mainly treated with a combination of plasma exchange, high-dose steroid and an anti-platelet aggregation agent. Two of them died within 3 weeks but the other two showed improvement after 3 weeks. As the clinical course and symptoms of TTP varied, it should be treated with combination therapies for a long period.
