Narrowing Racial Disparity in Kidney Transplant Outcomes

To conclude our three-part blog series on how the AST and its members are working to mitigate racial disparities in transplantation, I have invited AST member Tanjala Purnell to summarize her recent study of trends in kidney transplant outcomes among black recipients. Overall, her findings give reason for optimism, as her data show that traditionally underserved populations are indeed gaining ground as outcomes for recipients of all races steadily improve. No doubt more work needs to be done in the area; the AST remains committed toward reaching our strategic goal of seeing all transplanted organs function for the natural senescence of the recipient.

Tanjala S. Purnell, PhD, MPH, Assistant Professor, Transplant Surgery and Epidemiology, Johns Hopkins University School of Medicine

Kidney transplantation (KT) is the best available treatment for most patients with chronic kidney failure, offering longer life expectancy and improved quality of life as compared with long-term dialysis treatment. Despite these benefits, previous reports suggest that black transplant recipients experience poorer outcomes, such as higher kidney rejection and patient death, than white transplant recipients. Our research team at the Johns Hopkins Epidemiology Research Group in Organ Transplantation and the Johns Hopkins Center to Eliminate Cardiovascular Health Disparities wanted to examine whether this disparity has improved in recent decades. Our findings were recently published in the Journal of the American Society of Nephrology (JASN).

Using data from the Scientific Registry of Transplant Recipients (SRTR), we compared information on 63,910 black and 145,482 white adults who received a first-time live donor kidney transplant (LDKT) or deceased donor kidney transplant (DDKT) in the United States between 1990 and 2012. We hypothesized that advances in immunosuppression and post-transplant management might differentially benefit black kidney transplant recipients, who were disproportionately burdened by immunological barriers, and contribute to reduced racial disparities in kidney transplant outcomes.

Key findings from our study include:

1. Over time, 5-year failure rates of the transplanted kidney after DDKT decreased from 51.4% to 30.6% for blacks and from 37.3% to 25.0% for whites; 5-year failure after LDKT decreased from 37.4% to 22.2% for blacks and from 20.8% to 13.9% for whites.
2. Among DDKT recipients in the earliest group of patients, blacks were 39% more likely than whites to experience 5-year failure, but this disparity narrowed to 10% in the most recent group.
3. Among LDKT recipients in the earliest group, blacks were 53% more likely than whites to experience 5-year failure, but this disparity narrowed to 37% in the most recent group.
4. There were no statistically significant differences in 1-year or 3-year failure rates of transplanted kidneys after LDKT or DDKT in the most recent groups.

Our research demonstrates a dramatic improvement in KT outcomes for black patients and a significant reduction in the disparity in KT outcomes between black and white patients. This finding is significant and exciting because it may provide nephrologists and patients with added confidence to aggressively promote access to KT in minority communities. It is important that all patients with advanced-stage kidney disease receive timely clinical assessments and access to high-quality information about KT as a treatment option. This will help to address patient concerns and may encourage patients to discuss KT as an option with their family members, friends, and members of their extended social networks who may also be interested in and suitable to serve as a potential living kidney donor for the patient.

Study investigators include Tanjala S. Purnell, PhD, MPH; Xun Luo, MD, MPH; Lauren M. Kucirka, PhD; Lisa A. Cooper, MD MPH; Deidra Crews, MD, ScM; Allan Massie, PhD; L. Ebony Boulware, MD, MPH; and Dorry L. Segev, MD, PhD. The authors were supported by grants from the National Institutes of Health.