Transplant specialists, when evaluating kidneys from donors, try to find out how likely they are to have kidney failure after transplantation into recipients. Their risk calculator takes into account a variety of factors, including the donor’s age, height, weight, and history of diabetes. And, to the frustration of some researchers, it also includes donor race.
Kidney of black donors, living or dead, automatically decreases as a higher risk.
Some experts are now asking if there is a better way to evaluate kidneys from black donors, which may rely more on genetic screening than on the race to assess the risk of failure.
The proposed genetic screening will examine whether donors carry two copies of APOL1 in a gene strongly associated with kidney disease. Since most black donors do not have that genetic variation, experts argue, their kidneys should not be downgraded automatically.
But before introducing that change, researchers say they need to determine if, in fact, donor kidneys that have risky forms of APOL1 are more likely to fail.
The first indication came from a study by Dr. Barry Friedman of Wake Forest University in North Carolina, where 1,153 dead donor kidneys were transplanted in 113 different transplant programs. It found that the kidneys of dead donors, with two risky forms, were twice as likely to have kidney failure as the kidneys of donors who did not have a gene mutation or none at all.
But that research needs to be replicated in a larger research effort. A large-scale study sponsored by the National Institutes of Health to evaluate living and dead donors is underway with APOLLO. Researchers are examining kidney donors for APOL1 and are following the fate of thousands of transplant patients who have received kidneys from black American donors in more than 97 transplant programs.
In the study, living donors can decide if they want to learn the results of their genetic testing and if they want their kidney recipients to know the results as well. Medical privacy regulations prohibit doctors from telling kidney transplant candidates if there is a discrepancy without the consent of a living donor.
Dr. Friedman said that regardless of the results of the study, more transplant centers are promoting the idea of genetic testing in people who want to donate kidneys.
Until recently, he added, “many transplant centers have said they don’t want to talk about it.”