Matching Algorithm

Alliance for Paired Kidney Donation's Algorithm for Transplant Pairing

In the U.S., more than 100,000 people are waiting for a kidney transplant, but only 17,000 of them will receive a kidney this year. Of those, only 6,000 come from living donors. For the kidney patients who are fortunate enough to have a friend or family member step forward to donate, most are incompatible.

For patients and their families, the odds are overwhelming. The Alliance for Paired Kidney Donation is rewriting that story.

By including those incompatible pairs in the paired donation registry, the APKD is seeing more than a 50% rise in matches. That means 50% more patients who are finding the gift of life. With more pairs in the system, the rise in matches will continue to climb, and that’s exactly what the APKD is working toward.

How does it work?

The APKD uses a Nobel prize-winning algorithm, developed by Alvin Roth, to match one incompatible pair with another. A scoring rubric, developed by a team of healthcare professionals, is used help find the best possible match.

“The way the algorithm works in kidney transplants begins with data that we speak of as a compatible graph. You can think of a compatible graph as the participants in the kidney exchange, where patients and donors are pairs. Sometimes there are no direct donors, and sometimes there are people who are waiting for a donor kidney, but don’t have a living donor. What the algorithm does is try to recommend a set of transplants as it tries to find the maximum gauged set of matches. So, it tries to find as many of those as possible, and strings them together in a chain. So the surgeons can go ahead and accomplish those transplants.” Alvin Roth, 2012 Nobel Prize in Economics Sciences


Scoring Rubric

The scoring rubric was adopted by the Scientific Operations Committee on February 6, 2014.

The APKD software awards points according to the following criteria:

DR-locus mismatches 0 mismatches 2.0
1 mismatch 1.0
Any other mismatches 0.0
Zero-antigen mismatch Yes 6.0
No 0.0
High PRA >=80 10.0
>=50 6.0
Any other PRA 0.0
Travel distance Same center or same city 3.0
Any other distance 0.0
Pediatric recipient Age <=5 4.0
Age <= 17 2.0
Any other age 0.0
Recipient once was donor Yes 6.0
No 0.0
Known negative cross match and PRA >=80 Yes 6.0
No 0.0


Donate Today!