Another milestone in pig-to-human transplantation has been crossed, with doctors at New York University Langone today announcing the world’s first combination pig kidney and heart pump transplant. The recipient is a 54-year-old woman named Lisa Pisano who was diagnosed with terminal kidney disease and heart failure.
What Made George Takei Write a Children’s Book About World War II?
The concept of animal-to-human organ transplantation, or xenotransplantation, has been appealing for decades, given the longstanding shortage of human donor organs. But it’s only recently that this approach has started to seem within reach, thanks largely to advances in gene-editing technology that have allowed scientists to create pigs that are more compatible with human biology. One important distinction is that pigs and other mammals normally produce the sugar alpha gal in their muscles, while humans don’t.
Over the past few years, various research teams—including scientists at NYU Langone—have been successfully experimenting with these pigs. Their experiments have largely involved animals and a few people declared brain-dead, whose bodies their families allowed to be kept mechanically alive for a time while the donated organ is monitored. More recently, health regulators granted permission for researchers to perform these transplants in living humans on an experimental basis. In March, 62-year-old Richard Slayman became the first living human to receive a genetically modified pig kidney transplant, which was performed by doctors from Massachusetts General Hospital.
Like other recipients of these modified organs, Lisa Pisano had few other options available to her. She had reached end-stage kidney disease that required constant dialysis to manage, and she had a long history of heart problems, including a recent episode of cardiac arrest. But she wasn’t a good candidate for a typical heart or kidney transplant due to several chronic conditions and a high level of antibodies to human tissue that would worsen the chances of success.
Pisano likely would have benefited from receiving a left ventricular assist device (LVAD), a heart pump that can take over some of the organ’s functioning. These devices are either used to keep people stable while they wait for a heart transplant or as a long-term treatment for people not eligible for one. But her pre-existing kidney disease would typically rule out this option. And without a heart pump, she likely had only days to weeks more to live. The NYU doctors decided to ask Pisano if she would be willing to receive both the pump and a new pig kidney, which she quickly agreed to.
The first-of-its-kind procedure was performed by two separate surgical teams at NYU, over the course of nine days in early April. The heart pump was implanted first on April 4, followed by the kidney transplant on April 12. And though Pisano has experienced some complications and is still being monitored at the hospital, she appears to be recovering well so far.
“It is incredible to consider the scientific achievements that have led to our ability to save Lisa’s life, and what we are endeavoring to do as a society for everyone in need of a life-saving organ,” said lead transplant surgeon Robert Montgomery, director of the NYU Langone Transplant Institute, in a statement.
Though this is the second pig kidney transplant in as many months and fourth pig organ transplant overall, there are some important differences between them. Aside from the added complexity of implanting a heart pump, the NYU team opted to use a pig with only a single gene edit (the removal of alpha gal), while the Mass General team used a pig that had more than 60 genetic changes. The NYU team believes that this one edit will be enough to make pigs compatible with humans, in combination with existing immunosuppressant therapy. They also transplanted over the pig’s thymus, an organ that helps train immune cells. Emerging research has suggested such dual transplants can lessen the risk of rejection and improve compatibility between a donor organ and its new host.
Even if things continue to go smoothly, Pisano still has a long recovery and an uncertain future ahead of her. And it will ultimately require successful clinical trials for this technology to become available to the public at large. But NYU researchers and others are already working with the Food and Drug Administration to move ahead with these trials. For her part, Pisano is hopeful about the potential of this treatment for herself and others in her situation. “All I want is the opportunity to have a better life,” Pisano said in a statement.
