The expansion of kidney transplantation from living donors over the last several decades has included greater racial and ethnic diversification of the donor population. In the United States, the fraction of non-white living kidney donors rose from 24 percent in 1988 to 30 percent in 2011, representing more than 1700 donors. Currently, 12 percent of living kidney donors in the United States are African American and 13 percent are Hispanic. Because most countries, including the United States, do not currently maintain national registries that effectively track long-term donor outcomes, much of the information on postdonation health has been drawn from single-center, retrospective studies. The largest cohort study of living kidney donors published to date found no adverse impacts of donation on survival or end stage renal disease (ESRD) compared with general population registry controls (1), but notably, more than 98 percent of the sample was white. Racial differences in the burden and consequences of health complications among non-white persons in the general U.S. population are well documented. However, disparities in health after kidney donation have only recently raised attention.
In addition to more complete national collection of postdonation follow-up data, strategies to expand the evidence base for donor counseling and informed consent include database integration projects. Recent linkage of Organ Procurement and Transplantation Network (OPTN) registry data with the Social Security Death Master File demonstrated that while surgical and long-term mortality were higher in African American donors compared with white donors, long-term mortality did not exceed that of matched healthy non-donor controls (2).
Race-related differences in the frequency of ESRD and medical comorbidity after donation are also becoming apparent. Integration of OPTN donation records with Centers for Medicare & Medicaid Services (CMS) ESRD reporting forms revealed that while ESRD is uncommon after kidney donation, the ESRD rate in African American donors is nearly five times that of white donors (3). We linked administrative data from a private insurance provider with OPTN donor registration data and found that compared with white donors, African American donors had a 50 percent higher risk for postdonation hypertension and more than twice the risks of medication-treated diabetes and chronic kidney disease (CKD) diagnoses. Hispanic donors also had twice the risk of CKD and nearly three times the risk of drug-treated diabetes (4). Preliminary data presented at ASN Kidney Week 2012 using similar methods also support consistently higher rates of medical complications in African American and Hispanic donors compared with white donors regardless of sample or payer source (5). While novel methods of risk stratification such as apolipoprotein L1 genotyping in African Americans hold promise for identifying certain high-risk donors in the evaluation phase, the direct impact of donation on medical and renal outcomes after donation remains uncertain.
As policies for the informed consent, medical evaluation, and follow-up of living organ donors are receiving more attention and formalization by the organizations that guide and regulate transplantation practice, continued efforts to strengthen the evidence that underlies best practices applicable to donors with diverse demographic profiles are needed. These efforts should include assembly of healthy controls for assessment of risks directly attributable to donation as an important priority. In the meantime, practitioners should be frank with potential donors about what is currently known and what remains unknown about health outcomes after living donation across racial and ethnic groups.
Krista L. Lentine, MD, MS, is affiliated with the Center for Outcomes Research and the Abdominal Transplant Program at the Saint Louis University School of Medicine in St. Louis, MO. Dorry L. Segev, MD, PhD, is affiliated with the Abdominal Transplant Program, Department of Surgery, Johns Hopkins University, Baltimore, MD.
Segev DL, et al.. Perioperative mortality and long-term survival following live kidney donation. JAMA 2010; 303:959–966.
Cherikh WS, et al.. Ethnic and gender related differences in the risk of end-stage renal disease after living kidney donation. Am J Transplant 2011; 11:1650–1655.
Lentine KL, et al.. Racial variation in medical outcomes among living kidney donors. N Engl J Med 2010; 363:724–732.
Lentine KL, et al.. Racial Variation in Medical Outcomes among Older Living Kidney Donors: (From the WHOLE-DONOR Disparities Collaborative) J Am Soc Nephrol 2012; 23(Suppl):93A.