[Rituximab and Dexamethasone Combined with Cyclophosphamide for Treatment of Relapsed and Refractory Immune Thrombocytopenia].

Objective: To evaluate the efficiency and safety of rituximab and dexamethasone combined with cyclophosphamide for treating patients with relapsed and refractory immune thrombocytopenia (ITP).
Methods: Twelve patients with relapsed and refractory immune thrombocytopenia were prospectively enrolled in this study, and received rituximab 375 mg/m(2) once a week for 4 weeks, dexamethasone 40 mg once a day for consecutive 4 days, and cyclophosphamide 500 mg/m(2) biweekly for 2 weeks. The levels of IFN-r and IL-4 in peripheral blood of patients were measured by enzyme-linked immunosorbent assay (ELISA), and the percentages of Breg, Treg and Th17 cells were detected by flow cytometry before and after treatment. Efficiency was evaluated according to platelet counts, and side effects were observed.
Results: Six out of 12 patients reached to complete remission and 4 patients reached to partial remission, with the total response rate 83.33%. The platelet counts [(115.42 ± 76.60) × 10(9)/L] after treatment were significantly higher than that before treatment [(115.42 ± 76.60) × 10(9)/L] (P < 0.001). The ratio of IFN-r/ IL4 after treatment (5.89 ± 2.30) was very significantly lower than that before treatment (7.00 ± 2.73) (P = 0.002). The percentage of Breg cells after treatment [(21.27 ± 4.28)%] were much significantly higher than that before treatment [(15.48 ± 1.67)%] (P < 0.001). The ratio of Treg/Th17 after treatment (3.07 ± 1.50) was significantly higher than that before treatment (0.98 ± 0.45) (P < 0.001). Infusion reaction was observed in 1 patient, secondary hypertension and hyperglycemia were in 1 patient, and pneumonia in 2 patients.
Conclusion: Rituximab and dexamethasone combined with cyclophosphamide can improve the outcomes of patients with relapsed and refractory immune thrombocytopenia patients and they were well tolerated, its mechanism may be related with the balance between T cell sunsets and Treg cells.