Kidney Donor Outcomes Cohort (KDOC) Study

Kidney transplantation extends and improves the lives of adults with end-stage renal disease (ESRD). Live donor kidney transplantation (LDKT) has many advantages over deceased donor transplantation for the recipient, including shorter or no dialysis exposure, immediate graft function, lower perioperative morbidity and mortality, and better long-term graft and patient survival. Also, it yields significant cost savings to the healthcare system overall. These relative advantages and other advances in the field (e.g., laparoscopic techniques, paired kidney exchanges) have led transplant candidates and programs to more proactively embrace LDKT as the primary treatment option. Living kidney donors now account for 40% of all kidney transplants performed in the United States during the past 10 years, and more than 90,000 adults have undergone living donor nephrectomy in the United States over the last 20 years.

Worldwide there have been few large-scale studies examining the short- and long-term outcomes of living kidney donation, and many have been limited by retrospective, cross-sectional, and/or single-center designs with no appropriate control group. Despite efforts to enhance understanding of donor outcomes, it is clear that we have more knowledge in some areas (e.g., surgical and short-term medical complications) than in others (e.g., long-term medical complications, psychological outcomes, financial impact). The relative paucity of multisite, prospective outcome studies is concerning, especially considering the expanding donor eligibility criteria used by transplant programs today. Over the past decade, criteria for acceptance of a living donor candidate has changed: some donor candidates who would not have been considered 15 years ago (e.g., those with hypertension, obesity, or no prior relationship with the recipient) are now readily evaluated by many programs.

Recently, the transplant community and changes in federal regulations have brought attention to the need for more systematic study of living donor outcomes. While reporting outcomes over a 2-yr period is now mandated by the Organ Procurement and Transplantation Network (OPTN) and the United Network for Organ Sharing (UNOS), most transplant programs do not systematically collect donor outcome data. The lack of such data is an important problem because, without it, we will continue to have considerable variability in informed consent processes for living donors and their recipients, as well as limited data to inform clinical practice and policy development. This study directly addresses several of the recommendations made by the U.S. Department of Health and Human Services' Advisory Committee on Organ Transplantation.

A. Design Overview

This is a six center, prospective observational cohort study. A total of 280 living kidney donors, 280 LDKT recipients, and 160 healthy comparison subjects meeting all eligibility criteria will be enrolled. Participants will complete the assessment protocol at 5 time points: prior to surgery (Baseline, T1), 1 month after surgery (T2), 6 months after surgery (T3), 12 months after surgery (T4), and 24 months after surgery (T5). The rationale for selecting these time points is that they correspond to the assessment intervals currently required by the OPTN/UNOS for living donor follow-up, which were selected by the Living Donation Committee as the most appropriate time points for gathering short- and long-term follow-up data.