Study of Tolerant Kidney Transplant Recipients

Following kidney (renal) transplantation, one possible complication is rejection of the new
kidney. This occurs as a results of the body's immune system attacking (or rejecting) the
newly transplanted kidney. After transplant, medicines known as "immunosuppressive" or
"anti-rejection" drugs are given to transplant recipients to help prevent rejection of the
transplanted kidney. If a transplant recipient stops taking these medicines, they almost
always reject their transplanted kidney. However, in some exceptionally rare instances,
transplant recipients who stop taking these drugs do not reject their kidney, and the kidney
keeps working. The recipients are said at that point to "tolerate" the transplanted kidney,
and this condition is referred to as "tolerance".

In this study, participants will be asked to provide consent for the collection of extensive
demographic and clinical information; medical histories; and blood and urine samples. Blood
and urine samples collected will be used to perform specific assays to help define
mechanisms of tolerance.

Originally the study included 11 groups as listed; however, at present only groups 1,4, and
8 remain active. Whereas the initial study duration was 6 years, this was extended to 11
years in order to follow over more extended time a B cell signature identified for tolerant
kidney subjects and how this signature may change. (Refer to publications section: Newell,
Kirk et al, J Clin Invest. 2010).

Inclusion Criteria:

- Must be a renal transplant recipient or living donor

- Meet the criteria for inclusion in one of the study enrollment groups

- Provide informed consent

Exclusion Criteria:

- AIDS [includes all HIV-infected persons who have less than 200 cells/mm(3) CD4+
T-lymphocytes/microL, or a CD4+ T-lymphocyte/micro liter or a CD4+ T-lymphocyte
percent of total lymphocytes less than 14, or who have been diagnosed with an
AIDS-defining condition as defined by the Centers for Disease Control and Prevention
(CDC)

- Current malignancy requiring recent surgery, ongoing chemotherapy or radiation

- Acute systemic infections within 30 days prior to enrollment

- Pregnancy

- Transplant of another organ

Note: Patients meeting any of the exclusion criteria, if identified to have been
clinically tolerant prior to the occurrence of the excluding condition, will be enrolled
and demographic data collected for the registry; however, the decision as to whether or
not to collect blood, urine, and tissue samples will be deferred until the participant's
condition improves and the clinically tolerant state persists.