Kidney-transplant chain broadens donations

It began in 2006 with one Michigan man's decision to donate his kidney to anyone who needed a transplant. That gift led to a total of 10 transplants over eight months through two paired-donation registries coordinating operations in six hospitals in five states.

The chain of transplants was orchestrated using computer software originally devised by Harvard Business School economists and Boston transplant experts involved in the New England Program for Kidney Exchange, as this Globe story explains. But there are some important differences between the New England program and the national one described in tomorrow's New England Journal of Medicine in an article whose authors include economists from Harvard and Boston College. New England donations must happen at the same time, but the chain described in the Journal article did not.

In the New England Journal paper, the Alliance for Paired Donation built on the principle that pairs of donors and recipients -- a husband and wife, for example -- who don't match can be linked to other pairs with matches made across compatible pairs. These kinds of arrangements have happened within hospitals, but what the Alliance and the New England exchange both do is use software to sort through a wider pool of donor and recipient candidates to find matches. Blood type and antibodies are important factors in the success of a kidney transplant.

The New England exchange requires transplants to be simultaneous, to guard against the donor in one pair giving a kidney but the recipient not getting one in return because the next donor reneged or was unable to complete the donation. But the Alliance said starting with a altruistic donor could make the process more flexible.

If after the altruistic donor gives a kidney to the recipient in the first pair, the donor fails to donate to the recipient in the second pair, the outcome may not be fair but the donor in the second pair has not been harmed and can give a kidney in a new pair or chain, the authors, led by Dr. Michael A. Rees of the University of Toledo Medical Center, say.

"The most controversial issue in the case of a nonsimultaneous, extended, altruistic-donor chain is whether paired donors can or should be trusted to donate a kidney after their own coregistered recipients have received transplant," they write. "We suggest that when paired donations are initiated by an altruistic donor, the transplantations do not necessarily have to be performed simultaneously."

Dr. Frank Delmonico of Massachusetts General Hospital, one of the architects of the New England Program for Kidney Exchange, disagreed.

"We do not leave our New England patients vulnerable to this hazard. And yet we have a successful program that utilized nondirected donors," the transplant surgeon wrote in an e-mail interview, using the term nondirected rather than altruistic to indicate donor who gives to a stranger.

Journal co-author Alvin E. Roth said the Alliance's transplant chain can multiply the altruistic donor's gift. The Harvard economist created the matching software with M. Utku Unver and Tayfun Sonmez, now of Boston College.

"This is a bid in getting more kidney transplants done," he said in an interview. "There are 70,000 people waiting for a kidney. What we'd like to do is nibble away at those numbers and get more transplants done. I don't think it's going to solve the whole problem but it solves these problems one patient at a time."