A pig heart has been beating away in the body of a confused baboon for 945 days — and it could be the key to saving human lives with animal parts.
Xenotransplantation, the process of transferring an organ from one species to another, is nothing new. But a study published Tuesday in Nature Communications showed that, thanks to a regime of immunosuppressive therapy drugs, five genetically modified pig hearts put into different baboons stayed alive — beating and growing, but not replacing the functioning baboon's heart.
One of them lasted 945 days — almost twice as long as the previous record. Before this report, the longest a heart survived was just 500 days.
"This has the potential to really move the field forward," Dr. Richard Pierson, a professor of surgery at the University of Maryland School of Medicine and one of the study's co-authors, said in a statement. "This new approach clearly made a difference. We obviously have a lot more work to do, but I'm confident that eventually this will be useful to human patients."
It's exciting, but potentially dangerous: Experts say xenotransplantation could be used to support human life. In current experiments, a pig heart just hangs out in a baboon's belly. But making that pig heart shoulder all the baboon's cardiovascular functioning is a hell of a lot more demanding. Plus, the baboons are on drugs that make them horrible at fighting disease. So while their immune systems don't fight the invading organ, they also stink at fighting sickness, meaning the baboons could be at risk of illness.
The next steps: This research could light a clear path toward building universal, transplantable organs that won't go to battle with a human body when they're introduced to the new environment.
"Since the start of this study a few years back, there have been more genetically modified pigs created," Dr. Will Eyestone, a professor of veterinary regenerative medicine at Virginia Tech who didn't participate in the study, said in a phone interview Wednesday. "They're getting closer to this idea of a universal donor organ that can be taken from a pig and put into a human with minimum immunosuppression. It's unprecedented."
Why we need this: Right now, the state of human organ donation is bleak. For every organ donor, there are about 20 people on the donor waiting list. Plus, bodyless organs aren't known for making it across the country and staying fresh enough to use, which is bad news for the guy who needs a heart in Ohio when the closest donor is in Nevada.
If hospitals had genetically modified pig hearts at their disposal, doctors wouldn't need to wait until someone died to free up a used one. This could save hundreds, if not thousands, of lives every year.