[Clinical characteristics and outcome of 69 patients with thrombotic thrombocytopenic purpura]

To analyze the clinical characteristics, diagnosis, treatment and outcome of patients with thrombotic thrombocytopenic purpura (TTP). The clinical data of 69 adult patients with TTP were retrospectively analyzed. There were 19 males and 50 females with a median age of 42 (18-79) years. PLASMIC score 6-7 was recognized in 82.8% (53/64) patients. The activity of von Willebrand factor-cleaving protease (ADAMTS13), which was detected in 21 patients before treatment, was less than 5% in 17 patients and 5%-10% in 3 patients. All 69 patients were treated with plasma exchange (PEX) and/or fresh frozen plasma infusion (PI), 43 of whom were also given glucocorticoid. In addition to PEX/PI and glucocorticoid, rituximab and/or immunosuppressants were administrated in 20 patients. The median follow-up time was 12 (1-57) months. The remission rate was 69.6%, while the relapse rate was 11.6%. The 2-year overall survival (OS) rate was 69.6%±5.5%. The univariate and multivariate analysis showed that relapsed/refractory disease was an independent risk factor for OS. The 2-year OS rate of relapsed/refractory patients was significantly lower than that of the rest patients (41.5%±9.8% vs. 83.7%±5.6%, P<0.001). Regarding the unfavorable prognosis in relapsed/refractory patients, rituximab and/or immunosuppressants are strongly recommended for sake of improving the overall survival.