Kidney Failure and Transplantation

African American, Native American and other minority populations are disproportionately affected by end stage renal failure. In 1996, African Americans, despite making up only 12.6% of the United States population, represented 29.8% of all people treated for ESRD in the U.S. Most at risk were black patients 20 to 44 years old who were 20 times more likely than their white counterparts to have hypertension related kidney failure. Hypertension is a leading cause for kidney failure, accounting for 25% (87,000) of the nearly 379,000 cases of kidney failure in 2001. A third of black adults versus only a fifth of white subjects suffer from hypertension, and there is evidence that black subjects may have a genetic predisposition towards hypertension. The environmental factors that may be involved include high salt diets, urban living, poverty and stress. Since minority patients may be less likely to have adequate medical care, those with hypertension are more likely to be untreated. The result of this imbalance in health care access is that African American subjects are 6 times more likely than white patients to have kidney failure from hypertension.

The preferred standard of care for ESRD is renal allograft transplantation. Unfortunately, there appears to be a striking disparity between black and white subjects regarding access to this life-saving intervention. Among patients considered appropriate candidates for kidney transplantation, black patients are less likely to be referred for evaluation, placed on a waiting list or actually receive a transplant. Moreover, African American subjects wait nearly 2 to 4 times longer on transplant waiting lists than do white subjects. According to the United Network for Organ Sharing, more than a third (21,093) of the 70,783 patients awaiting kidney transplants in 2006 were black patients.

Many believe that the current system for organ allocation ( setting aside an organ to give) is inherently unfair to African American subjects in that it is weighted according to human lymphocyte antigen matching (genetic matching), which favors white patients who have more HLA matches with prospective cadaveric donors because the majority of cadaveric donors are from white cadavers. Intensifying the problem is the fact that there are also fewer black living donors. Clearly, there needs to be more organ donation within the black community but the current deceased donor allocation system which is heavily weighted on genetic match between donor and prospective recipient should be reexamined to eliminate racial disparity in the distribution of organs. A plan to broaden the geographic allocation of kidneys and alter scoring of HLA point appears to permit greater opportunity for renal transplantation to minority candidate.

Recent analyses have shown that African American race is a significant independent predictor of early graft loss even when other potential negative effects were statistically controlled. Also, African American recipients of a kidney transplant are at high risk for early graft rejection and, therefore, require greater immunosuppression to maintain graft function. Unfortunately, this puts African American kidney recipients at risk for drug related toxicities and other complications. In addition, because of the higher rates of acute rejection and diminished allograft survival, some have suggested institution of immunosuppressive regimens tailored to reflect high immunological risk of black patients. Such studies have shown that African American patients have fewer rejection episodes when immunosuppressed with combinations of anti-rejection medications including tacrolimus, mycophenolate mofetil and sirolimus.

References:
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United Network Organ for Sharing (UNOS). Organ Procurement and Transplantation Network (OPTN). Available at http://www.unos.org/whatWeDo/research.asp.
Callender CO, Miles PV, Hall MB et al: Blacks, whites, and kidney transplantation: a disparity! But why and why won’t it go away? Transplant Rev 2002; 16:163
Epstein AM, Ayanian JZ, Keogh JH et al: Racial disparities in access to renal transplantation—clinically appropriate or due to underused or overuse? N Engl J Med 2000; 343: 1537
Klassen AC, Hall AG, Saksvig B et al: Relationship between patients’ perceptions of disadvantage and discrimination and listing for kidney transplantation. Am J Public Health 2002: 92: 811
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One Response to Kidney Failure and Transplantation

  1. Great article. I was not aware of the allocation process being predicated primarily on HLA tissue typing. Bone Marrow donation is based on HLA tissue typing and this is why he National Marrow Donor Program activily seeks donors from minority populations. However, the fact does remain the more repeat HLA tissue types are more prevelant in Caucasian populations as opposed to minority porpulations. A new allocation process with organ donation process is a good idea.

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