A new Mayo Clinic study, published in the June 2010 issue of Gastroenterology, disputes a long-held hypothesis that a donor's race has an impact on the success of liver transplants.
“In the absence of biologically plausible mechanisms, it is inappropriate to designate non-white donors as 'marginal'”
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Donor race has been associated with graft failure after liver transplantation, regardless of the recipient's race. However, a Mayo Clinic research team, led by gastroenterologist and hepatologist Ray Kim, M.D., questioned the biological plausibility of donor race uniformly being a contributor to poor outcomes, and hypothesized that a large part of the association between donor race and the possibility of graft failure is explained by differences in transplantation centers and other adjusted confounders (such as body size). The results of their analysis concluded that donor race is not a uniform predictor of graft failure in liver transplantation and should not be construed as an indicator of donor quality.
"A superficial look at the data suggests some correlation between donor race and outcomes. But when we dug deeper, we found that a true reason emerged for the difference in outcomes," said Dr. Kim. "Race may appear to be an important factor but, in reality, outcomes were more likely influenced by factors such as where the transplantation took place and whether the size of the organ was appropriate for the recipient, for example. Further, we found no evidence that liver transplantation across racial boundaries is associated with lower outcome than racially concordant donor-recipient cases."
By analyzing data from the Organ Procurement and Transplantation Network for nearly 11,000 adult patients who underwent primary liver transplantation in the United States from January 2003 to December 2005, the team examined the association between graft failure and donors whose race was African-American, Caucasian, Asian/Pacific Islander, and those classified as "other," who happened to mostly be of Hispanic origin.
In the United States, nearly 16,000 people are waiting for liver transplants. According to Dr. Kim, this study is an important contribution to the body of knowledge about donor organ quality. "In the absence of biologically plausible mechanisms, it is inappropriate to designate non-white donors as 'marginal'," says Dr. Kim. "Such a practice will not only further discourage organ donation among minority individuals, but also may create a perpetual misconception as their so-called 'marginal' organs are directed to 'marginal' recipients who may not have had as good of a chance for success due to their medical issues, and thus further decrease the chance for a successful outcome of transplantation."
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