Efficacy of standard dose rituximab for refractory idiopathic thrombocytopenic purpura in children

OBJECTIVE: The present study intends to investigate the efficacy and safety of standard dose rituximab for treatment of refractory idiopathic thrombocytopenic purpura (RITP) in children. PATIENTS AND METHODS: A total of 50 cases of children hospitalized with RITP in a hospital were enrolled in this study, and randomly divided into two treatment groups according to the therapeutic methods: rituximab group (n = 26) and vincristine group (n = 24). Another 20 healthy children receiving physical examination in the hospital during the corresponding period were enrolled as the control group. Before treatment the thrombocytes were counted with hematology analyzer and the CD19(+)/CD20(+) B cells in peripheral blood tested with flow cytometry in rituximab group. Then the children in the rituximab group were given standard dose rituximab at 375 mg/m(2) via four weekly intravenous drip, while those in vincristine group treated with vincristine at 0.02 mg/kg by intravenous drip once a week for three months. During the treatment the adverse drug reactions were observed and recorded. After the treatment, the efficacy of two drugs was each evaluated, and the thrombocytes and CD19(+)/CD20(+) B cells in peripheral blood of rituximab group were quantified in the same way, and the children in both treatment groups were followed up and the recurrence rate recorded. RESULTS: The total efficiency including complete response and partial response in rituximab group was significantly higher than that in vincristine group (69.2% vs. 37.5%, chi(2) = 9.74, p < 0.01). The prevalence rates of adverse reactions were statistically indifferent between two treatment groups during the therapy (11.5% vs. 8.3%, chi(2) = 0.62, p > 0.05). The follow-up visit showed that the recurrence rate of rituximab group including those showing complete response and partial response was significantly lower than that of vincristine group (22.2% vs. 55.6%, chi(2) = 7.24, p < 0.05). The peripheral blood platelet number of children showing complete response and partial response in group of rituximab was 106.7 +/- 32.5 x 10(9)/L after treatment and significantly higher compared with that before treatment (t = 12.48, p < 0.01). The amount of CD19(+)/CD20(+) B cells in peripheral blood of rituximab group after treatment was significantly lower than that before treatment (t = 6.71, p > 0.05). CONCLUSIONS: Rituximab may play a role in the efficacy by depleting B cells and can cure RITP in children without causing serious adverse reactions.