Surgeons have successfully transplanted a genetically engineered pig kidney into a patient who was declared brain dead. The surgery marks the longest time a pig organ has functioned in a human and is a step toward establishing an alternative source of life-saving organs, doctors at NYU Langone Health said. The surgeons used a kidney from pigs engineered to suppress the expression of the protein alpha-gal, which triggers an immediate rejection response by the human immune system. The team also embedded a portion of the pig’s thymus gland, which educates the immune system, underneath the surface of the kidney to prevent an immune system further attack on the graft.
Maurice Miller, 57, from upstate New York, died of a brain tumor and was pronounced brain dead, making him ineligible for routine organ donation. His family opted to donate his body to the study, which had been approved by an ethics committee and was funded by the New York State Department of Health. NYU’s researchers hope the research will help ease a shortage of donor organs, particularly for patients with chronic kidney disease.
The team transplanted the pig kidney into the brain-dead Miller with the help of a liver and lungs donated by another person. After a planned 54-hour monitoring period, the graft remained healthy and produced urine, which indicated it was working well. The pig kidney had not rejected or developed clots as the team expected, though they continued to monitor the patient closely for any signs of complications.
While the transplant is a significant milestone, the experiment remains in its early stages, the NYU researchers said. They are continuing to evaluate whether the pig kidney will be protected from rejection by using drugs that suppress the immune system instead of altering the genes. They also want to learn how the pig kidney performs in a larger animal and whether the changes are permanent.
Other attempts at animal-to-human transplants, known as xenotransplantation, have failed for decades because people’s immune systems quickly reject foreign tissue. But last year, with special permission from regulators, University of Maryland surgeons were able to implant a genetically modified pig heart in a dying man. That person survived for two months, but the heart eventually stopped functioning.
NYU researchers hope the work will lead to more animal-human transplants, but they are cautious. They are starting with kidneys because they are less prone to rejection than other organs, and they are focusing on pig hearts and livers before tackling lungs, which are more susceptible to rejection by the human immune system.
NYU Langone Health has doubled the number of orthopedic specialists in Suffolk County, with 23 providers and four practices. The network is ranked among the top 5 in the country for orthopedics and rehabilitation, according to U.S. News & World Report. The additions include a practice in Stony Brook and locations in Patchogue, Riverhead, and Hauppauge.