Rituximab Therapy in Adults with Refractory Symptomatic Immune Thrombocytopenia: Long-Term Follow-Up of 15 Cases

摘要

Objective: This paper prospectively evaluates the long-term followup[mean ± standard deviation (SD) duration: 89.7±19.4 months] dataof 15 patients (13 females and 2 males) with refractory symptomaticimmune thrombocytopenia (ITP) treated with rituximab.Materials and Methods: Rituximab was administered at 375 mg/m2weekly for a total of 4 doses. Complete response (CR) was defined as aplatelet count of ≥100,000/mm3 and partial response (PR) as a plateletcount of ≥30,000/mm3 but less than 100,000/mm3. Early response (ER)and late response (LR) were defined as response within 42 days andafter 42 days of initiation of rituximab therapy, respectively. Sustainedresponse (SR) was defined as response lasting for at least 6 months.Results: Mean age (±SD) at the start of rituximab was 46.6±11.3years. Mean platelet count (±SD) prior to rituximab treatment was17,400±8878/mm3. The mean time (±SD) between rituximab therapyand response to rituximab in early responders and late responders was1.8±1.3 weeks and 10±2.8 weeks, respectively. Mean durations (±SD)of ER and LR were 51±47.2 months and 6±4.2 months, respectively.Seven of the 15 patients (46.7%) showed an initial response torituximab (5 ER and 2 LR). The rate of SR over 6 months was 26.7%(4/15). Among the responders to rituximab, 3 (3/7, 42.9%) maintainedtheir response 1 year after rituximab treatment and 2 (2/7, 28.6%)had ongoing response 5 years after initiation of rituximab. Two of the7 patients (28.6%) still maintained their response 98 months afterinitiation of rituximab. All 5 initial responders with subsequent relapseachieved response from subsequent treatment modalities (3 CR, 2 PR).Conclusion: Our data confirm, over a long period of observation, thatrituximab is safe and effective in the management of patients withchronic refractory primary ITP.