Rituximab in Patients With Relapsed or Refractory TTP-HUS
Rituximab in Patients With Relapsed or Refractory TTP-HUS
The general objective of this study is to assess the efficacy and safety of Rituximab in the
 management of patients with refractory or relapsed thrombotic thrombocytopenic
 purpura-hemolytic uremic syndrome (TTP-HUS). There have been several case reports and case
 series describing the use of Rituximab in patients with TTP-HUS; however its use has not been
 studied in a large trial. It is hypothesized that Rituximab may ameliorate the severity of
 certain cases of TTP-HUS by decreasing the number of activity of B-cells which may result in
 decreased production of the ADAMTS13 protease inhibitor. Patients with TTP-HUS not responding
 to standard therapy or patients with relapsed disease may have particular benefit. Treatments
 that decrease the frequency of relapse or shorten the time to remission of TTP-HUS will be of
 benefit by decreasing the need for blood product support.
Inclusion Criteria:

 -  any patient 18 years or older diagnosed with relapsed or refractory TTP-HUS requiring
 therapy

 Exclusion Criteria:

 -  alternate cause of hemolytic microangiopathy (evidence of DIC, malignant hypertension,
 vasculitis, anti-phospholipid antibody syndrome, post-partum acute renal failure)

 -  congenital or familial TTP

 -  TTP occuring post-stem cell, bone marrow, or solid organ transplant

 -  drug-induced TTP

 -  pregnancy or breast-feeding

 -  history of hepatitis B or C infection

 -  prior rituximab treatment

 -  active or metastatic cancer

 -  other causes of thrombocytopenia such as ITP, myelodysplastic syndrome, confirmed or
 suspected drug-induced thrombocytopenia

 -  refusal to receive blood products

 -  hypersensitivity to blood products, plasma products, murine proteins, or any component
 of the Rituximab formulation

 -  geographic inaccessibility

 -  co-morbid illness limiting life expectancy to less than 2 months independent of TTP

 -  failure to provide written informed consent