Surgeons in Recent York removed a pig kidney less than two months after it was transplanted into Lisa Pisano, a 54-year-old woman with kidney failure who also needed a mechanical heart pump. The team behind the transplant says there were problems with the heart pump, not the pig kidney, and the patient is in stable condition.
Pisano struggled with heart and kidney failure and required routine dialysis. She was not a candidate for a classic heart and kidney transplant from a human donor due to several chronic medical conditions that made the likelihood of a good outcome less likely.
Pisano first received a heart pump at NYU Langone Health on April 4, followed by a pig kidney transplant on April 12. The heart pump, a device called a left ventricular assist device, or LVAD, is used in patients who are waiting for a heart transplant or are otherwise not candidates for a heart transplant.
In a statement provided to WIRED, Pisano’s medical team explained that they electively removed the pig’s kidney on May 29 – 47 days after the transplant – after several episodes in which the heart pump was unable to move enough blood through the transplanted kidney. Constant blood flow is essential for the kidneys to produce urine and filter waste. Without it, Pisano’s kidney function began to deteriorate.
“Overall, the kidney was no longer contributing sufficiently to justify continuing immunosuppressive therapy,” Robert Montgomery, director of the Langone Transplant Institute at Recent York University, said in a statement. Like classic transplant patients, Pisano had to take immunosuppressive drugs to prevent her immune system from rejecting the organ.
The kidney came from a pig whose genetics had been modified by Virginia-based biotechnology company Revivicor to lack a gene responsible for producing a sugar called alpha-gal. In previous research at Recent York University Langone, researchers found that removing this sugar prevented immediate organ rejection in brain-dead patients. During Pisano’s surgery, a donor’s thymus gland, which is responsible for “educating” the immune system to reduce the likelihood of rejection, was also transplanted.
A recent biopsy showed no signs of rejection, but Pisano’s statement said the kidney was damaged due to lack of blood flow. The team plans to study the explanted pig kidney to learn more.
Pisano is now back on dialysis, a treatment for patients with kidney failure, and her heart pump is still functioning. She wouldn’t be a candidate for a heart pump if she hadn’t received a pig kidney.
“We hope that Lisa will return home to her family soon,” Montgomery said, calling Pisano “a pioneer and hero of the effort to create a sustainable option for people waiting for an organ transplant.”
Pisano was the second living person to receive a kidney from a genetically modified pig. The first, Richard Slayman of Massachusetts, died in May, just two months after the historic transplant. The surgery was performed on March 16 at Massachusetts General Hospital. In a statement released May 11, the hospital said there was “no indication” that Slayman’s death was the result of the pig kidney transplant. The donor pig used in the Slayman procedure had a total of 69 different genetic changes.
The global shortage of donor organs has prompted researchers, including teams from Recent York University and Massachusetts University, to look into using pigs as an alternative source. However, the body immediately recognizes pig tissue as foreign, so scientists employ gene editing to make the pig’s immune system look more like human organs. How much gene change will be needed to make pig organs work in humans is a topic of much debate.
The University of Maryland also performed pig heart transplants in two people – one in 2022 and the other in 2023. In both cases, the patients were not eligible for human treatment. These donor pigs had 10 genetic changes and were also bred by Revivcor. Both recipients died approximately two months after transplantation.