Delayed graft function (DGF) increases risk of acute rejection after kidney transplantation (KTx). Interleukin-6, which is produced in DGF, is critical in directing naive T helper cells differentiation towards T helper 17 (Th17) and away from regulatory T (Treg) cells. The investigators hypothesize there is an increase in Th17 and a decrease in Treg expression in KTx recipients with DGF compared to those without, leading to immunologic consequences. The investigators will test their hypothesis by measuring in both groups expression of Th17, Treg, and related cytokines in blood, urine, kidney biopsy, and kidney preservation fluid, and correlating these results with immunologic events.

All adult recipients of a primary kidney transplant will be eligible. Subjects will have blood samples drawn from which we will isolate lymphocytes and analyze the Treg population based on surface markers as well as a functional assay. The measures of Treg function will be compared to outcomes including DGF, graft survival and graft function, as well as the development of immunological complications such as donor-specific antibody production, acute rejection, IFTA and opportunistic infection.

Inclusion Criteria:

• Kidney transplant recipients

Exclusion Criteria:

• None

All kidney transplant recipients at our institution will be recruited prior to their operative procedure.

There is no plan to make the experimental data available to participants. Their clinical data, however, is available to them through their treating physician.