Efficacy and Safety of Rituximab for Refractory and Relapsing Thrombotic Thrombocytopenic Purpura: A Cohort of 10 Cases.

OBJECTIVE

Idiopathic thrombotic thrombocytopenic purpura (TTP) is a life-threatening disorder mediated by autoantibodies directed against ADAMTS13. This provides a rationale for the use of rituximab in this disorder. We report our experience and the outcome of 10 cases of TTP (9 refractory and 1 relapsing) successfully treated with rituximab in combination with plasma exchange (PE) and other immunosuppressive treatments.

METHODS

The diagnosis of TTP was based on clinical criteria and supported by severe deficiency of ADAMTS13 activity and presence of inhibitors in seven cases. Rituximab was started after a median of 18.6 sessions of PE (range: 5-35) at the dose of 375 mg/m(2)/week for 4-8 weeks.

RESULTS

Complete remission was achieved in all patients after a median time of 14.4 days of the first dose (range: 6-30). After a median follow-up of 30 months (range: 8-78), eight patients were still in remission and two developed multiple relapses, treated again with the same therapy, and achieved complete responses; they are alive, and in complete remission after a follow-up of 12 and 16 months.

CONCLUSION

Rituximab appears to be a safe and effective therapy for refractory and relapsing TTP. However, longer follow-up is recommended to assess relapse and detect possible long-term side effects of this therapy.