Bone marrow and blood samples from both non-sensitized kidney transplant recipients and sensitized kidney transplant recipients will be collected. The samples will be used to compare the effect immunosuppression has on the antibody producing cells from both of these kinds of transplant recipients. Bone marrow will be collected from sensitized kidney transplant recipients before desensitization therapy prior to transplantation and at the time of kidney transplant surgery. Non-sensitized patients will have bone marrow collected only at the time of kidney transplant surgery. Blood will be collected at the same time point that the marrow is collected in both kinds of patients.