This study is being done to collect blood and bone marrow samples for biologic studies of antibody producing cells. Donor specific antibodies can cause damage to the kidneys after they are transplanted. The study will look at the impact of immunosuppression on antibody production by antibody producing cells.

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.

Participants must be between the ages of 18 and 70 years of age and undergoing a kidney transplant.

Three groups will be studied:

1. Non-sensitized renal allograft candidates prior to any therapy;
2. High DSA recipients--Recipients with a positive T or B cell cytotoxicity crossmatch or a B cell flow cytometric crossmatch assay with a channel shift >350 at baseline against their living donor at baseline and
3. Low DSA recipients-recipients with a negative T and B cell cytotoxicity assay, but a positive T or B cell flow cytometric crossmatch with a B cell channel shift <350.