This article reviews the impact of HLA-based allocation of cadaveric kidneys with regard to racial disparities.

The National Organ Transplantation Act of 1984 mandated the creation of an Organ Procurement and Transplantation Network (OPTN) in order to establish a national list of individuals needing organs and a system for matching available organs with individuals on the list. This duty was then awarded to the United Network for Organ Sharing (UNOS), which became explicitly responsible for “allocating all usable organs equitably among transplant recipients according to established medical criteria.” The authors of this paper raise four main points to support their argument that this language has led to the development of a system that is inherently racist.

First, the current UNOS system assigns points to patients based on how well-matched they are to the organ donor on the six antigens identified at the HLA-A, HLA-B, and HLA-DR loci. That is, persons with the lowest number of antigenic matches are least likely to receive the transplant. This puts blacks in need of organ transplants at a disadvantage because such donations largely come from whites, and HLA antigens are distributed differently among races. Additionally blacks have less well-defined HLA antigenic specificities than do whites.

Second, the need for organs is higher in minority groups, as minority populations are at increased risk of developing ESRD relative to whites. Blacks desiring transplantation are, for poorly defined reasons, less likely than whites to have a suitable living donor and are relatively more dependent on availability of cadaveric kidneys. Although the authors “emphatically support efforts to promote organ donation among blacks (and whites),” they argue that “increased donation by African Americans is not the sole solution to racial disparity in renal transplantation.” Due to the overrepresentation of blacks in the ESRD population, there will always be more potential black recipients than donors. Although some have proposed the establishment of a nationally-based HLA matching system as a solution to some of problems with the current system, the authors of this article argue such a change would not resolve racial disparities. Nationally, blacks constitute 12% of the population, 8% of the donors, but 34% of those with ESRD.

Third, HLA matching does not necessarily improve survival. Recent advances in renal transplantation hold the promise of nonexclusionary efficiency of transplant procedures. Studies report that graft survival for all recipients of first grafts, regardless of HLA match, equal those reported for only the best matches.

Finally, although the current system emphasizes HLA matching to enhance efficiency of transplant procedures, it already incorporates some steps that accommodate equity over efficiency. For example, because those with O-blood type had longer waits, a UNOS policy was amended to specify that O kidneys be offered only to O recipients (except in the presence of a six-antigen match). Additionally, patients who are highly sensitized to HLA antigens receive points to enhance equity, despite the knowledge that presensitization is a risk factor for graft loss. Finally, children, who have poorer graft survival than adults, receive additional points to enhance access to renal transplantation.

The authors recommend that more equitable distribution between blacks and whites must be accomplished and would be if kidneys were allocated locally (except in extremely well-matched kidneys, whose higher rate of graft survival is well-supported); partial matching were deemphasized; and a policy were implemented that enhances allocation to blacks (allocating “race-conscious points”). The authors acknowledge the problems with defining race and suggest self-identification as a solution.

Comments
Three of these authors disputed the arguments of the Gaston et al. article, and one supported the arguments.

Hassol A. Race and allocation of kidneys for transplantation. JAMA 1994;271(4):269-70; discussion 270-1.
Hassol support the arguments made by Gaston et al and adds two further points. First, according to UNOS policy, cadaveric kidneys allocated to patients must be paid back with a kidney from the next suitable donor of the same blood type. Thus, the advantage for white patients is clearly perpetuated over time. Second, patients improve their odds of receiving a kidney by listing at multiple transplant centers, but the UNOS does not adjust for multiple listing. This also exacerbates the racial disparities, because black and white patients may not be equally able to afford the travel and other costs to be placed on lists at distant transplant centers.

Wolicki KT. Race and allocation of kidneys for transplantation. JAMA 1994;271(4):270; discussion 270-1.)
Wolicki states that the system proposed by Gaston et al “injects racial bias into kidney allocation.” She does not feel it has been clearly demonstrated that transplant technology has advanced enough to disregard HLA-based allocation. She states, “A cautious accommodation of racial biases based on disease incidence and prevalence may be an appropriate interim measure pending further advances in transplant medicine and behavior, which will allow the best possible use and allocation of cadaveric kidneys.”

Lazda A. Race and allocation of kidneys for transplantation. JAMA 1994;271(4):270; discussion 270-1.
Lazda disputes a specific point raised in the Gaston et al article with regard to the success of the Regional Organ Bank of Illinois, where a local variance of the UNOS point system on organ distribution that gave greater emphasis to waiting time than HLA-match (other than “excellent” matches) was tested. Lazda argues this system benefited patients with longer waiting times, such as blacks (contrary to the statements in the Gaston et al. article). Gaston et al replied by noting that in order for this system to benefit blacks, they would have to accumulate longer waiting times than whites, a system already flawed by inequality.

Norman DJ. Racial inequities in kidney transplantation: the UNOS perspective. United Network for Organ Sharing. JAMA 1994;271(18):1402-3.
This letter disputes the arguments of Gaston et al. “The authors fail to clearly demonstrate a causal relationship between the role of HLA matching in the current renal allocation system and unequal renal transplant waiting times observed across racial groups.” They argue that “postallocation factors [including positive cross-match, logistical considerations, and various aspects of physician and patient judgment] largely determine which patients receive transplants.”
Gaston et al. respond by stating that the HLA-based allocation system is not wholly responsible for racial inequalities, but it is a significant contributing factor.