Mass exchanges result in more kidneys for difficult-to-match recipients
When a person donates a kidney to a broad pool of potential recipients, the altruistic act can kick off a long chain of donations that leads to more transplants for hard-to-match patients, a mathematical analysis concludes.
Many people needing kidney transplants have a willing donor, but they can’t take the kidney because it’s not compatible with their blood type or immune system. Paired exchanges, where incompatible donor/recipient pairs swap kidneys with another incompatible pair, is one trick for getting kidneys into hard-to-match patients. Another trick is a donor chain: A person gives a kidney to a clearinghouse or kidney exchange, which can set off a chain of donations.
Within the kidney transplant community, there’s been an ongoing debate over whether long chains ultimately mean more transplants. “The mathematical question was, are we really transplanting more people?” says Alvin Roth, an expert in game theory and market design