WASHINGTON -- The overhauled United Network for Organ Sharing (UNOS) kidney transplant allocation guidelines will likely remove a controversial age-matching component from its algorithm, researchers said here.
The requirement that 80% of deceased-donor kidneys be matched with a patient whose age is within 15 years, plus or minus, the donor's age will be taken out, largely because of substantial public criticism, Kenneth Andreoni, MD, of Ohio State University in Columbus, and chair of the kidney guideline committee, said during a session at the National Kidney Foundation meeting.
"It's not going to go forward," Andreoni told attendees, noting, however, that other recent studies have shown the typical transplant matching window to be plus or minus 14 years.
The original guideline, released for comment in February 2011, held that the top 20% of kidneys should be allocated based on post-transplant survival estimates, with the remaining 80% allocated based on age-matching.
But critics, including medical ethics specialist Lainie Friedman Ross, MD, PhD, said the system would give more kidneys to younger patients and discriminate against older ones.
Ross and colleagues will publish an alternative allocation strategy in June, in the American Journal of Transplantation. She said this strategy will bring better kidneys to younger patients, but only after ensuring an equal opportunity for all patients.
In addition to removing the 80% portion of the 20/80 rule, as the panel referred to it, Andreoni said the new guideline may also amend the process for determining "extended-criteria" donors, which make up the highest-risk organs in the system. Currently, these donors are classified by being age 60 or older, or age 50 and up but with negative predictors on 1-year graft survival.
Patients are educated about the risks associated with these organs and can opt-in to receive such a transplant. But Andreoni said using a different system, specifically the Kidney Donor Profile Index (KPDI), which incorporates a wider variety of factors to determine the risk of graft failure, would more accurately characterize these organs, a large proportion of which are discarded.
"The hope is to increase the efficiency of the organ allocation system for these harder-to-place donated organs," he told MedPage Today.
He noted, however, that the 20% portion of the algorithm will likely remain in place.
Ross said that was unfortunate because that part of the algorithm remains biased toward younger patients. The problem, she said, is that it is challenging to appropriately define the "best" candidates and organs.
The 20/80 rule "doesn't achieve the balance of efficiency and equity," Ross said. "It's not that age-matching is wrong, but when you know more kidneys are going to go to younger patients, that makes age-matching unethical."
The alternative guideline that Ross' group has developed is called the Equal Opportunity Supplemented by Fair Innings (EOFI) system. It is also a two-pronged strategy: The first step gives all wait-list transplant patients a similar chance at all organs. In step two, younger kidneys are directed toward younger patients with end-stage renal disease because they've had fewer healthy life-years, Ross said.
Ross said the EOFI system is "less efficient than age-matching but maintains the balance of efficiency and equity."