In February 2007, Garet Hil’s youngest daughter was diagnosed with kidney failure. The 10-year-old girl went on dialysis. She would need a transplant to survive. Hil was eager to give her one of his kidneys.
At first, it looked like the two were a match. But 36 hours before the operation was scheduled to take place, Hil learned that he had become incompatible. His daughter’s antibody composition had changed, and her body would reject his kidney. He was no longer a viable donor. The transplant was cancelled.
It was a terrifying moment. Hil’s wife was incompatible. So too were three uncles. The family scrambled to find other willing donors, testing 15 potential donors before discovering that Hil’s 23-year-old nephew, Tristan, was a match. Tristan donated his kidney, and today both donor and recipient are doing well.
For his part, Hil emerged from the experience convinced there had to be a better way. He wasted no time. In February, he had learned the bad news about his daughter; in July, she received her kidney. By September, Hil had established the National Kidney Registry, a nonprofit organization designed to facilitate kidney swaps, saving or improving the lives of thousands of Americans facing kidney failure.
To appreciate the brilliance of the National Kidney Registry, you first need to understand the severity of America’s kidney problem. There are 400,000 people on dialysis, 77,000 of whom are currently waiting for a deceased-donor kidney. Only 17,000 transplants are performed each year, and the typical wait time for a deceased donor kidney is between three and 12 years. Over 4,000 people die every year waiting for a deceased-donor kidney, and more are dying every year as the waiting list continues to grow.
Of the 17,000 annual transplants, roughly 10,000 come from deceased donors. The rest come from live donors, which, from an epidemiological perspective, is far preferable; on average, live-donor kidneys last nearly twice as long as deceased-donor kidneys. In order for a live donor to match a recipient, the two must have a compatible blood type and achieve a match of body antigens, which are measured on a scale of zero to six. (A typical parent and child will have a three-antigen match; identical twins have a six-antigen match.) The higher the antigen match, the better the chances that the kidney will not be rejected and that it will function longer over time.
Yet even though live-donor transplants produce better outcomes than deceased-donor transplants, the mechanism for live-donor transplants has only recently begun to modernize. The first live-donor transplants were conducted in the 1950s. For decades afterward, if you wanted a kidney from a living donor, you had to find someone from your family who was willing, compatible, and healthy enough to donate. Unless you had a large family, it was a difficult proposition.
In 2000, Johns Hopkins Hospital started the first paired-exchange program. In a paired exchange, kidneys are traded between two donor-recipient pairs. Imagine, for instance, that Adam wants to give a kidney to his wife, Amy, but he cannot because they are incompatible. But what if Adam is compatible with Bill, who needs a kidney and had hoped that his (non-compatible) sister, Beth, could provide it? If Beth matches Amy, and Adam matches Bill, the two pairs can easily swap kidneys. Paired exchange broadened the universe of potential matches and changed the way people thought about live-donor transplants.
But the idea of paired exchange was just the precursor to the truly revolutionary concept: the donor chain. In 2007, doctors created the first donor chain using a “non-directed” kidney, a kidney donated by an altruistic living donor willing to donate to a stranger. Using that “free agent” kidney, doctors were able to create a match in an unmatched pair, whose incompatible donor was then used to resolve another unmatched pair, and another, and another, and so on. Donor chains take a non-directed donor kidney and use it to resolve a series of unmatched sets, setting off a chain of transplants which can facilitate high-quality matches indefinitely.
Donor chains hold the solution to that massive, 77,000-person waiting list. If people needing a kidney can recruit willing donors, it will no longer matter whether or not they are compatible. If you put enough pairs into a pool, you will eventually find matches for everybody. Even better, every live-donor kidney recipient frees up one more space on the waiting list for a deceased-donor kidney. But first, you have to build the pool.
Enter the National Kidney Registry. Hil realized that America’s kidney shortage isn’t a medical problem. It’s a mathematical problem.
Hil, a former Marine with an MBA from Wharton, has spent most of his career building and running technology companies. To create the Registry’s matching system, he turned to a former colleague, Rich Marta, who has a background in software development. They needed a computer program that could arrange donor/recipient pairs by compatibility (and a finite number of other variables) and find ways to link them into three-way clusters to form chains. To get an idea of the hidden complexity, understand that a single non-directed donor kidney can facilitate 30+ transplants per year—that is, if you can find the right path for the chain to follow. Which is no small task, since the possibilities increase exponentially: A pool of 100 unmatched pairs generates 10 billion possible three-way combinations. A pool of 500 pairs generates 31 trillion possible combinations.
Marta called his program Best Match, and his algorithm produced better results than anyone in the world has yet achieved. In donor/recipient pools of over 100 pairs, the majority of matches it found were equal or better than the three-antigen match that is typical between a parent and a child. The better the match, the longer the kidney lasts. The Registry pool is currently just shy of 100, and is expected to be well over 100 by year’s end.
With BestMatch in hand, the National Kidney Registry began acting as a paired exchange facilitator, creating a pool of donor/recipient pairs and finding the sequences which would yield the longest possible chains of high-quality matches. After its founding in September 2007, the Registry facilitated its first triple-swap in February 2008. To date, it has facilitated 13 transplants and has identified 21 more that it hopes to complete by Christmas. The Registry projects that, with adequate funding, it will facilitate 300 transplants in 2009, and as many as 10,000 by 2013. Such fantastic growth rates are attainable because the chains compound: Each chain created today will keep producing transplants even as new chains are created.
In order to grow according to plan, the Registry’s pool will need to expand to several hundred donor/recipient pairs. The goal seems attainable: There are between 5,000 and 15,000 incompatible pairs in the United States today. Moreover, 400 people have already enrolled with the Registry to serve as non-directed altruistic donors—each of whom will initiate a new chain. With only 100 non-directed donors, the Registry can start 100 chains with a capacity to facilitate 3,000 transplants per year.
Better yet, if Hil can grow the Registry’s pool to 500 donor/recipient pairs, computer simulations indicate that fully one-third of the transplants facilitated will be age-compatible, six-antigen matches. Such transplants generally last 40 to 60 percent longer than the typical living-donor match. As an additional bonus, people with failing kidneys will be in a better position to get their transplants before they are forced to begin dialysis treatment. (The transplant success rate is roughly 5 to 25 percent higher for these preemptive transplants.) Many elite medical institutions have already signed up. Three of the nation’s top five transplant centers are now working with the Registry, and Hil hopes to have 15 of the top 20 on board within a year. And a coterie of world- renowned medical experts has joined the Registry’s medical board, providing the support and guidance needed to tackle this enormous problem.
“This is one of the most exciting things I’ve been involved with in 30 years in this field,” Gabriel Danovitch, director of UCLA’s kidney and pancreas transplant program, told the Wall Street Journal. Other leading experts share Danovitch’s enthusiasm. Sandi Kapur, M.D., chief of kidney transplantation at Manhattan’s Presbyterian-Cornell University Medical Center, says that the “National Kidney Registry’s matching process has revolutionized living-donor transplants.” Of course, the Registry’s costs will scale as the organization grows. Thus far, however, Hil has been able to keep the program lean. Based in Long Island, New York, the Registry has seven people working for it, including Hil, but only two of them receive any compensation—and even those are just token salaries of $1,000 per month. The rest of the staff, including Hil and Marta, volunteer their time.
As for funding, Hil has taken on much of that burden, too. He and his wife donated $250,000 to establish the Registry. Over the past year, they raised another $150,000 from 300 individual donors and private foundations, none of whom gave more than $11,000. To this point, neither the government, insurance companies, nor any medical institutions have contributed to the National Kidney Registry. Hil nevertheless hopes to continue leveraging private funding in order to scale up the Registry’s work. Once the system has expanded, he hopes transplant centers, insurance companies, and Medicare will step up and provide funding. Certainly it would be in their best interest to do so. The longer patients wait for a deceased-donor transplant, the more strain is placed on the American healthcare system. If the Registry reaches its goals, it stands to save the nation some $55 billion in healthcare costs over a 10-year period—all while creating better outcomes for patients.
The National Kidney Registry is already on a trajectory to facilitate even more transplants, but Hil feels there is no room for complacency. “I see my daughter in every recipient in our Registry,” he explains. “I know what it’s like to take a little girl to dialysis three times a week and feel the pain of being unable to donate a kidney. I don’t want anyone to go through that. So for me, it’s pretty straightforward. I will never give up. These people really need help and we can provide it immediately. But most importantly, I have seen the impact that a transplant had on my daughter—it is a life-altering event—and I want this for everyone who needs it.”
Jonathan V. Last is a staff writer for The Weekly Standard and a columnist for the Philadelphia Inquirer.