| PERSPECTIVE |
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[May 2, 2003] -
Organ transplants save thousands of lives every year. But thousands more who need transplants go without. A researcher at the University of Nebraska Medical Center is exploring ways to overcome that problem, using organs grown in pigs. Dr. Bill Beschorner believes his research will lead to custom grown organs transplanted from pigs to people. It's a process called xenotransplantation. Several years ago Dr. Beschorner formed a company called Ximerex to explore ways to make xenotransplantation a practical option for patients who need new organs. He came to UNMC's Lied Transplant Center in 1997. Now he's closer than ever to making his dream come true.
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Transcript of Pigs to People
[Brad Penner] Most Nebraskans know pigs, or at least know about pigs. We've seen pigs at the county fair, or maybe even a farm. Pigs are why one of the country's top transplant scientists moved his work to Nebraska.
[Dr. Bill Beschorner] Around 1991, 92, I got interested in xenotransplantation or the transplantation of pig organs into people. I came up with a novel approach to get around the major problem of xenotransplantation, which is rejection. My initial work was done at the Johns-Hopkins Hospital, and then I worked at a farm off in Baltimore County for about a year and a half and eventually outgrew that. I needed a place in which there was a very strong transplant program and a very strong program in raising pigs. And that's what brought me to Omaha, Nebraska.
[Brad Penner] The Lied Transplant Center at the University of Nebraska Medical Center provides the facility for Dr. Bill Beschorner's research. The pigs are raised at a facility near Oakland, Nebraska. Dr. Kelly Lechtenberg runs the operation.
[Dr. Kelly Lechtenberg] It's nice to be able to contribute uh through veterinary medicine into the human medicine field in an area that uh you know, is kind of non-traditional.
[Dr. Beschorner] He's certainly qualified. You know, he's a DVM, PhD, a surgeon, but he's also uh willing to take risk on things, and so we got together, we said well, you know, do you want to try this? Yeah, let's go ahead and let's see if it works, and so it's a great partnership.
[Dr. Lechtenberg] We got together and compared notes and found that a lot of things that the xenotransplant project needed that we were pretty well equipped to provide for them in terms of support, animal care, documentation and quality control issues.
[Brad Penner] These pigs will never find themselves on a dinner table, but organs harvested from their descendants may someday wind up on an operating table.
[Dr. Beschorner] Pigs probably have greater homology or greater physiology that resembles humans than any other species of animal. They're also able to be raised under incredibly clean conditions. And we can also raise them, you know, very quickly. A generation time for a pig is about 10 months. In other words, from the time that they're born to the time that they can give birth is about ten months. So you can quickly raise a herd of pigs you know for this purpose. So there's a number of things that just fit together very nicely for using pigs.
[Brad Penner] But you still can't take an organ from an ordinary pig and put it into a human being. The immune system would detect and reject the foreign tissue.
[Dr. Beschorner] Pigs are a lot different than humans uh and have a lot of different molecules that they're gonna recognize. So I felt we needed a novel way, an innovative or revolutionary way to deal with all these antigens and still not suppress the immune system.
[Brad Penner] Dr. Beschorner found a way to reduce the risk of rejection.
[Dr. Beschorner] If you needed a transplant, we would take some bone marrow, and we would put it into the fetal pigs and then usually about three our four months later, after these cells have grown within the fetal pig and it become educated or tolerant to the pig, then at that point, we would take the spleen from the pig, which has your cells in it, collect those cells and put em back into you and then at the same procedure, at the same time, we would take the heart or the kidney and transplant that into you.
[Brad Penner] So that would change my immune system to a degree where it would not attack the organ.
[Beschorner] Exactly. Yeah.
[Brad Penner] Dr. Beschorner announced a successful test of this process last February. He and his team transplanted hearts from pigs to sheep. The sheep's own heart was not removed. The pig heart was attached to the sheep to test for rejection.
[Dr. Beschorner] Very basically we were able to prevent rejection for a prolonged period of time. Uh there were a few animals that did come down with a mild form of rejection which we could treat.
[Dr. Beschorner] Everybody's run into this brick wall though of how do you prevent rejection uh without severely suppressing the immune system of the-of the patient. Uh and I think we're unique, fairly unique in that-in that regard in that we're able to get over that hump.
[Brad Penner] In the next several months Dr. Beschorner will likely transplant organs from pigs into baboons. These pigs look pretty normal on the outside, but on the inside they're very different.
[Dr. Lechtenberg] They're super clean status, if you will, the fact that they're serologically and culture negative for-for numerous pathogens of interest.
[Brad Penner] Because of careful breeding and environmental control, these pigs have never been exposed to a number of germs that could cause disease in humans.
[Dr. Lechtenberg] The important thing is we have to start on any of these tissues that are intended ultimately to go into humans, we want to start with a biologically very safe animal.
[Brad Penner] And, Dr. Lechtenberg says, organs grown in pigs like these, under controlled conditions, might be healthier for the recipient than donated human organs.
[Dr. Lechtenberg] From a safety perspective and from a viability perspective, uh one can make an argument that organs produced specifically for a given transplant procedure um, you know, might be safer from an infectious disease standpoint than some procured through more traditional systems.
[Brad Penner] Answers to those kinds of questions will only be found when the research moves to the final, critical level.
[Dr. Beschorner] I would say after we start the primate study, it'll probably be about a year and a half to two years until we're ready to do human trials. So it's not that far off.
[Brad Penner] Dr. Beschorner says his inspiration and motivation comes from the hundreds of thousands of people who need, but can't get transplants every year. Many more might be helped if an experimental treatment for diabetes proves successful. Some patients with diabetes are getting transplants of insulin-producing islet cells, ending their need for insulin.
[Dr. Beschorner] The frustrating part is that uh if you use human islets from human pancreases, we could only transplant about a thousand patients a year. The problem is that there's over a million Americans with Type 1 diabetes and 15 million with Type 2 diabetes. So you can see the shortage is tremendous there.
[Brad Penner] Dr. Beschorner believes the islets, heart, and kidneys of pigs should function well in humans. But pig livers work differently.
[Dr. Beschorner] A pig liver will produce proteins that only work in the pig. It won't work in the human. To get around that, we propose to grow human cells within the pig liver and make it essentially, make the pig liver part human.
[Brad Penner] Skeptics say pig to human transplants just won't work. Dr. Beschorner says more than a decade of research and even more years of experience tell him it will succeed.
[Dr. Beschorner] I'm very confident and I've-I'd bet the ranch on this thing. I put my whole life on the line for it.
[Brad Penner] Dr. Beschorner worked on research into bone marrow transplants at Johns Hopkins. He heard the same kind of doubts then.
[Dr. Beschorner] We made bone marrow transplantation work. And now, of course, it's the treatment of choice for people with leukemia. We're going through the same period with xenotransplantation right now. But having gone through the experience with the bone marrow transplantation, you know, I have the courage and belief that we can accomplish this with the xenotransplantation.
[Brad Penner] Someday the descendants of these pigs may save a life, maybe your life. Reporting for Statewide, I'm Brad Penner.