Rituximab as an adjunct to plasma exchange in TTP: a report of 12 cases and review of literature.

Idiopathic thrombotic thrombocytopenic purpura (TTP) is caused by the production of autoantibodies against the Von Willebrand factor cleaving enzyme. This provides a rationale for the use of rituximab in this disease. We report a retrospective review of 12 patients treated with rituximab for TTP refractory to plasma exchange. Eleven patients were treated during initial presentation, and one patient was treated for recurrent relapse. Ten patients responded to treatment. Median time to response after first dose of rituximab was 10 days (5-32). Of the 11 patients treated during initial presentation, nine remain free of relapse after a median follow-up of 57+ months (1+-79+). Two patients died during initial treatment. One patient was lost to follow-up 1 month after achieving complete response. The patient treated for recurrent disease during second relapse remained disease free for 2years, relapsed and was treated again with rituximab, and was in remission for 22 months. She relapsed again, was retreated, and has now been in remission for 21+ months. We conclude that rituximab is an useful addition to plasma exchange treatment in TTP, but its exact role and dosing need to be verified in prospective studies. Copyright 2008 Wiley-Liss, Inc.