Adjuvant Rituximab and/or Chemotherapy Improves Outcome of Thrombotic Thrombocytopenic Purpura: University of Cincinnati Experience.

Abstract Background: Thrombotic thrombocytopenic purpura (TTP) is a rare but serious hematological disease. Immune therapy related to anti-ADAMTS13 antibodies has not been investigated systematically. Remission duration, morbidity and mortality with and without chemotherapy in addition to plasmapheresis have not been studied prospectively. A small number of case studies make treatment guidelines non-uniform and outcomes difficult to assess. Duration of plasmapheresis, the mainstay of therapy impacts heavily on the patient's quality of life and healthcare resources. Hypothesis: Rutuximab based chemotherapy in addition to plasmapheresis is better than plasmapheresis alone. Objectives of the study: To compare plasmapheresis alone (P) to plasmapheresis in combination with Rituximab based chemotherapy (P+R/RC) for the duration of plasmapheresis required for the achievement of remission. Methods: Retrospective chart review of all patients diagnosed with TTP at the University of Cincinnati Medical Center from 1997–2007. The variables reviewed were: Patient demographics, types of treatment received (i.e. P alone versus P+R/RC), duration of plasmapheresis, remission rate and duration of remission. Results: Eighteen patients were treated between 1997 and 2007. The mean age was 33 years (Range 17–61). Sixteen patients (88%) were females. Thirteen patients (72%) were African American. Six patients (33%) had elevated creatinine and ten patients (56%) had change in mental status at diagnosis. The etiology of TTP was idiopathic in 11 patients, drug related in 3 patients, HIV related in 1 patient and associated with pregnancy in 2 patients. All patients were treated with plasmapheresis, however eleven patients (61%) were in the first group (P) treated with plasmapheresis alone and seven patients (39%) were in the second group (P+R/RC) treated with plasmapheresis in addition to immunosuppressive therapy. As shown in Tables 1, and 2, the results trended towards a shorter duration of plasmapheresis required for remission following P+R/RC versus P alone, in the same patient (n=7), though the data did not reach statistical significance due to the small sample size. However when the duration of plasmapheresis after P+R/RC was compared to the total duration of plasmapheresis in TTP patients who did not receive Rutuximab based chemotherapy (P) (p=0.06), there was a statistical significance.Four patients (22%) relapsed in group 1 (P) and one patient (6%) relapsed in group 2 (P+R/RC). Conclusion: Plasmapheresis with immunosuppressive therapy trended towards a decreased duration of plasmapheresis, relapse rate, and increased duration of remission in patients with TTP. Prospective studies with immunosuppressive therapy upfront are needed to substantiate this. Median duration of plasmapharesis in patients with rituximab based therapy Duration Median 25%–75% p value Pre-immunosuppressive therapy 168.5 39, 977.0 0.15 Post-immunosuppressive therapy 71 32, 133.0 Signed rank test Median duration of plasmapharesis alone (group 1) versus plasmapharesis with rituximab-based therapy Group Median 25%, 75% p-value 1 216.5 91.5, 564.0 0.06 2 71 32.0, 133.0 Wilcoxon test