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

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.