Rituximab Therapy for Patients on Kidney Transplant Waiting List With Positive Donor Specific Crossmatch to Living Donor

Primary Objectives: * Conversion of a positive donor specific cross-match to a living donor to a negative cross-match thereby allowing successful renal transplantation. * Transplant success or failure following the desensitization protocol. * Determination of the effect of rituximab on the kinetics of donor specific antibodies (DSA). * Determination of the effect of rituximab on the kinetics of B-cell subpopulations in peripheral blood and/or secondary lymphoid organs (lymph node biopsies at time of transplant, if available) in both responders and non-responders using flow cytometry and/or immunohistochemistry. Secondary Objectives: -Decrease in incidence of humoral rejection to less than 50 % at 1 year.