Couples who cross-donate kidneys.

Health and medicine explained.
Dec. 20 2005 4:22 PM

Love Match

Couples who cross-donate kidneys.

Kidney swap. Click image to expand.
Kidney swap

When Tom Packard began suffering from kidney failure, his fiancee offered to give him one of her kidneys. But Packard, a 65-year-old Manhattan bank executive, and Ann Heavner, 59, weren't a compatible match. After two more donors fell through, the couple showed up in the office of Dr. Lloyd Ratner, director of renal and pancreatic transplantation at New York-Presbyterian Hospital/Columbia University Medical Center. Ratner punched a few keywords into his personal database and found a 71-year-old New Jersey man who could use Heavner's kidney—and whose 62-year-old wife could give hers to Packard.

So, the two couples made a deal. Last spring, in four operating rooms, four surgeons simultaneously conducted what's known as a "kidney swap." All four patients have recovered. Last month, they spent Thanksgiving together.

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In 2004, nearly 4,000 people in the United States died while waiting for a kidney. Paired exchanges like the one Dr. Ratner initiated increase the odds of finding compatible matches and making successful transplants. Swaps also involve live donors, whose organs have a 50 percent chance of lasting more than 20 years, about twice as long on average than organs from a cadaver. A study published this fall in the Journal of the American Medical Association found that of 22 patients who received kidneys in a paired exchange and were tracked for more than a year on average, only one had failed, and that was because of unrelated problems.

In short, kidney swaps look like the best of medical ingenuity, market efficiency, and our wheeler-dealer American ways—akin to calling up your friend after a forgettable date and saying: "Bill and I didn't hit it off. But he might be perfect for you!" Yet, while the first successful kidney transplant took place more than 50 years ago, fewer than 100 paired exchanges have been performed in the United States to date. Ratner conducted the first one in 2001 at Johns Hopkins; in contrast, South Korea has been swapping in greater numbers since the early 1990s. So, where's the Match.com of kidney donation?

It's coming, but not soon. Swaps look simple case by case. But on a larger scale, the concept is onerous to implement—and the ethics need to be sorted out.

Patients with kidney failure generally have two options. They can join the 64,000 people on the list for an organ from a dead donor. Or they can jump the queue and join the nearly 7,000 people a year who get a live kidney transplant by asking a family member or friend to donate one of theirs. A match, however, requires a donor and a recipient with compatible blood and tissue types, and a recipient who doesn't have a high level of antibodies, which could cause him or her to reject the organ. Hard-to-match patients, about 20 percent of the total number, have a 1-in-6 chance of getting the kidney they need, even after as many as eight years on the waiting list run by the United Network for Organ Sharing, a national group. Transplant doctors lately have made huge progress in transferring incompatible kidneys. But there's still a high risk of rejection.

Medical and legal ethicists have long debated the conundrums of live-organ transfers. The National Organ Transplant Act definitively bans sales by forbidding transplants that are done for "valuable consideration." But kidney swaps seem legally murky: If I offer to give my kidney to my sister but we're not a match, am I "buying" her a chance at someone else's by cross-donating? So far, the transplant community has allowed such incentives. The New England Organ Bank lets donors give a live kidney to someone else in exchange for helping their friend or relative move up on the list for a cadaver kidney, even if no direct swap can be arranged.

For medical ethicists like Art Caplan at the University of Pennsylvania, swaps are OK because no money changes hands, and because inherently they're not coercive. "You're using an exchange to circumvent a problem of biology in that it's difficult to find good matches," he says. Also, swaps aren't bargains that can be enforced: If your husband gets his kidney first and you change your mind about donating yours, no one can compel you to undergo surgery. (Though doctors aim to put both the donors to sleep at the same time so neither can back out.)

What's to stop patients, though, not only from enlisting their siblings and spouses but also paying a person they don't know to go into the database on their behalf? Of course, there's always a chance someone could buy a kidney from a stranger directly. And some scholars have argued that a kidney market is no more troubling than a market for human eggs. But as long as kidney sales remain out of bounds, swaps seem to increase the temptation to cut an unsavory deal.

First, though, transplant doctors have to set up some version of a gigantic swap meet. The success of paired exchanges depends on pooling enough donors to improve the chance for good matches. UNOS, which has a government contract to match kidney patients with cadaver organs, is a logical choice to run a live swap program. UNOS already has in place a patient database and standards and ethics committees. (Currently, live donations are handled independently by transplant centers and organ procurement groups.)