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).