Is the U.S. Throwing Away Too Many Donor Kidneys?

MONDAY, Oct. 29, 2018 — When deciding which donated kidneys can help desperate patients on waiting lists, the United States might want to follow France’s lead and lower the bar, a new study argues.

There’s a worldwide shortage of donor kidneys available for transplantation, but France appears to have been more aggressive than America in responding to that shortage, said study co-author Dr. Peter Reese. He’s a kidney transplant doctor and associate professor at the University of Pennsylvania’s Perelman School of Medicine.

The study shows that France is using kidneys from donors who are much older, on average, than in the United States.

“Basically they’re accepting donor kidneys that are much lower quality and higher risk,” Reese said. “To me, it shows that this other country with a very advanced health care system that looks a lot like our own in many ways is pushing the envelope on the donors and the transplants that they’ll do, whereas we really aren’t.”

There currently are more than 95,000 people on the U.S. kidney transplant waiting list, according to the United Network for Organ Sharing (UNOS), the nonprofit that manages America’s organ transplant system.

Despite this shortage, approximately 2,000 donated kidneys are discarded each year, researchers said.

“In the United States, there are a lot of kidneys that are procured but not transplanted,” said Dr. David Klassen, chief medical officer for UNOS. “As far as we can tell, there are some we believe really could be transplanted and should be transplanted.”

To gain some insight into the issue, Reese worked with a French research team to compare the relative health of donated kidneys in each country and how the organs are used.

The researchers evaluated transplant data from 2004 to 2014, during which time more than 156,000 kidneys in the United States and nearly 30,000 kidneys in France were procured for transplant.

A much higher proportion of kidneys were higher-risk organs in France, scoring an average 65 on the Kidney Donor Profile Index (KDPI), compared with an average score of 42 for U.S. kidneys used in transplant.

Lower scores are associated with longer function. For example, kidneys with a KDPI between 0 and 20 are expected to function an average of 11.5 years, while those with a KDPI between 21 and 85 are expected to function about 9 years, according to the federal Organ Procurement and Transplantation Network.

French surgeons tend to accept kidneys for transplantation from much older recipients, the researchers found.

“The mean age of the French donors was 17 years older than the United States,” Reese said. “They are responding to the organ crisis by accepting older and older donors.”

Accepted kidneys in France also tended to be more often from donors with chronic conditions like high blood pressure and diabetes, Reese said.

Because of this, the French average KDPI rose from 54 to 67 during the decade, while the U.S. average KDPI increased only from 42 to 44.

“Over 10 years in the United States, there was really no change in the age of the donors and the quality of the donors,” Reese said.

The United States could do a better job matching kidneys to recipients, even if the organs aren’t the best quality, Reese concluded.

He gave the example of a kidney donated by an 80-year-old person.

“It would be a mistake to take that kidney in the United States if the recipient is 30 years old, but we have people who are on our kidney transplant waiting list who are over 70,” Reese said. “If we tried hard, I don’t think we would have too much difficulty finding appropriate recipients for these kidneys from older donors.”

Klassen, who wasn’t involved with the study, said that U.S. transplant centers tend to be risk-averse because they don’t want to run afoul of regulators and endanger their certification.

“Transplanting organs that might be viewed as higher risk into potential recipients who might be viewed as higher risk, transplant centers view that as something they would choose not to do,” Klassen said.

To be fair, there are some donated organs that simply shouldn’t be taken. “Just because a kidney is procured and possibly could be transplanted doesn’t mean that it should be,” Klassen said.

There also are major differences in the organ donation and transplant system between France and the United States, in terms of how organ quality is judged and kidneys are biopsied at the time of organ offer. “It’s hard to say the results of one country would directly translate to another country,” Klassen said.

But the U.S. Centers for Medicare and Medicaid Services tacitly admitted there’s an oversight problem. The agency has put out for comment a rule change that would loosen its monitoring criteria, Klassen said.

“They would look at other measures of program quality and not focus specifically on patient one-year outcomes as the sole measure of program quality,” Klassen said. “I don’t think monitoring of patient and graft outcomes will ever go away, but I think using a broader palette of quality of measures would be an appropriate thing to do in terms of judging transplant programs.”

The study was scheduled for presentation Sunday at the American Society of Nephrology’s annual meeting, in San Diego. Such research is considered preliminary until published in a peer-reviewed journal.

More information

The Organ Procurement and Transplantation Network has more about the Kidney Donor Profile Index.