Vincristine as an Adjunct to Therapeutic Plasma Exchange for Thrombotic Thrombocytopenic Purpura: A Single-Institution Experience

Abstract

Background: Thrombotic thrombocytopenic purpura is a potentiallylife-threatening condition. Although the introduction of therapeuticplasma exchange has reduced mortality rates from over 90% to 10%-20%, approximately 40% of patients relapse, and outcomes maybe fatal in refractory patients. There is clearly a need for additionaltherapeutic approaches.Aims: To describe the outcomes of relapsed/refractory thromboticthrombocytopenic purpura patients treated with vincristine as anadjunct to therapeutic plasma exchange.Study Design: Cross-sectional study.Methods: The medical records of all relapsed/refractory patients withthrombotic thrombocytopenic purpura treated with vincristine adjunctto therapeutic plasma exchange between October 2000 and December2016 were retrospectively reviewed. Diagnosis of thromboticthrombocytopenic purpura was based on clinical history, physicalexamination, and laboratory examinations. Patient demographics,laboratory findings, initial date and duration of therapeutic plasmaexchange, dosage and time of administration of vincristine, andoutcomes were recorded.Results: The study included 15 patients [median age: 37 years (range:26-65); 7 women and 8 men] with either relapsed or refractorythrombotic thrombocytopenic purpura who were treated withvincristine as an adjunct to therapeutic plasma exchange for a total of22 episodes. Eighty-seven percent of patients achieved remissions in20 of 22 episodes, with a median duration of remission of 29.5 months(range: 3-105). After a median follow-up of 55 months, 11 patientswere alive. Vincristine was well tolerated with no safety concerns.Conclusion: Vincristine offers a reasonable option for the treatmentof patients with relapsed/refractory thrombotic thrombocytopenicpurpura. Further studies evaluating vincristine in the front-line settingand in the relapsed/refractory setting are needed to validate the role ofvincristine in thrombotic thrombocytopenic purpura patients.