It is well known that African Americans have a lower rate of living donor transplantation compared with Caucasians. In a recent article published in the American Journal of Kidney Diseases, Dr. Erin Hall and colleagues found that transplant center–level factors may play a role in the degree of racial disparity in living donor attainment. In this post, corresponding author Dr. Dorry Segev (DS), from Johns Hopkins School of Medicine, discusses the motivations behind this study and the implications of these findings with Dr. Vinay Nair (eAJKD), eAJKD advisory board member.
eAJKD: Would you please summarize the main points of your study?
DS: The purpose of this study was to evaluate center-level effects of the disparities in live donor kidney transplantation. The most important finding was that there is no racial parity anywhere in the country. Basically, at every center in the country, African Americans have a lower chance of a live donor kidney transplant than their non–African American counterparts. These range from 35% lower odds at the centers with the least disparity to 76% lower odds at the centers with the most disparity.
eAJKD: The disparities between centers were really remarkable. Do you believe that some of this reflects center practices, different patient populations, or perhaps both?
DS: It is probably a combination of both. It is possible that we were seeing disparities for African Americans because African Americans happened to be registered at centers that had low rates of living donor transplantation. Then, on average, it would seem that African Americans had lower rates of living donor transplants rather than what was really a problem of those centers having lower rates of living donor transplant. When we did the center-level analysis, we showed that this is not indeed the case. What is unclear is why there is less disparity in some centers and more disparity in others. We did the center-level analysis using a hierarchical regression model where you can put in certain variables, like the number of candidates, the proportion of candidates that are African American, the proportion of candidates that are listed prior to dialysis, and the rates of live donor transplants at that particular center. What you can’t put in, which is one of the limitations of the study, is the center-level policies, the center-level practices, etc.
eAJKD: I thought it was interesting that centers with a higher population of African Americans had even greater racial disparity in living donor transplant attainment.
DS: This is an unfortunate finding that might represent a culture at the center or within the local communities. If African Americans have a lower chance of identifying a live donor and the live donors that come forward have a lower chance of being eligible for donation, it may lead to a regressive attitude at the centers where referrals slow. Or, there may be less incentive at centers where it happens more frequently. Interestingly, the centers that had the higher rates of live donor transplantation overall had less disparity. Centers that are good at getting people live donors or helping people spread awareness in their community about transplantation may be centers that help address disparity.
eAJKD: Do you believe it may be that African American communities have more comorbidities and less suitable candidates for donation?
DS: Yes, I think there’s evidence that if an African American patient comes forward with the same number of potential donors as a non–African American patient, the likelihood that those potential donors will be ruled out is probably higher in the African Americans. This may be due to the higher prevalence of diseases that result in kidney disease. So, it’s true that as an African American patient you need to push harder to find a healthy, willing live donor.
eAJKD: Did you also look into the relationship between donor and recipient? For example, were African Americans less likely to have related kidney donors because relatives of African Americans are more likely to have shared comorbidities, such as kidney disease, hypertension, and obesity?
DS: We did not look into that in this study. In this study, the denominator was listed candidates and the numerator was of those that found living donors. The question of whether African Americans are drawing their live donor pool from a different population than non–African Americans should be pursued.
eAJKD: There’s been an explosion of data demonstrating an increased risk for kidney disease among African Americans with relatives that have end-stage renal disease, possibly due to polymorphisms of the APOL1 gene, and much of living donation still comes from relatives. I wonder if these recent discoveries will further decrease the rate of living donation in African Americans.
DS: It could, although according to recent data, about half of live donors are not blood related in this country. So it may be true that there is less opportunity for African Americans to find live donors from among their family, but there’s certainly plenty of opportunity to find a living donor from the community.
eAJKD: What do you suggest are the next steps in evaluating this disparity; to better understand the difference in living donor transplant rates between centers?
DS: The next step with regard to the center-level effect is to go to the high performing centers, those with the lowest disparity, and find out what they’re doing. By learning how they’re taking care of patients, we may be able to implement policies and practices to reduce disparities at other centers.
eAJKD: Do you have any suggestions on how we can reduce racial disparities in living donor kidney transplant attainment?
DS: The action item conclusion from the study is that the centers with higher rates of live donor transplantation not only had higher rates of live donor transplantation for everyone, but also had less racial disparities. The way to address this is the general way that we’ve been trying to address things overall, which is to help people find living donors.