Rituximab and Intravenous Immune Globulin for Desensitization during Renal Transplantation

Abstract

Few options for transplantation currently exist for patients highly sensitized to HLA. This exploratory, open-label, phase 1-2, single-center study examined whether intravenous immune globulin plus rituximab could reduce anti-HLA antibody levels and improve transplantation rates. Between September 2005 and May 2007, a total of 20 highly sensitized patients (with a mean [+/-SD] T-cell panel-reactive antibody level, determined by use of the complement-dependent cytotoxicity assay, of 77+/-19% or with donor-specific antibodies) were enrolled and received treatment with intravenous immune globulin and rituximab. We recorded rates of transplantation, panel-reactive antibody levels, cross-matching results at the time of transplantation, survival of patients and grafts, acute rejection episodes, serum creatinine values, adverse events and serious adverse events, and immunologic factors. The mean panel-reactive antibody level was 44+/-30% after the second infusion of intravenous immune globulin (P<0.001 for the comparison with the pretreatment level). At study entry, the mean time on dialysis among recipients of a transplant from a deceased donor was 144+/-89 months (range, 60 to 324). However, the time to transplantation after desensitization was 5+/-6 months (range, 2 to 18). Sixteen of the 20 patients (80%) received a transplant. At 12 months, the mean serum creatinine level was 1.5+/-1.1 mg per deciliter (133+/-97 micromol per liter), and the mean survival rates of patients and grafts were 100% and 94%, respectively. There were no infusion-related adverse events or serious adverse events during the study. Long-term monitoring for infectious complications and neurologic problems revealed no unanticipated events. These findings suggest that the combination of intravenous immune globulin and rituximab may prove effective as a desensitization regimen for patients awaiting a transplant from either a living donor or a deceased donor. Larger and longer trials are needed to evaluate the clinical efficacy and safety of this approach. (ClinicalTrials.gov number, NCT00642655.)