Genetically modified pigs, at a farm in Virginia, are being bred for their organs.Credit: Andrew Caballero-Reynolds/AFP via Getty
A 53-year-old clinically dead man has become the first person to receive two kidneys and a whole liver from a genetically modified pig. The man’s organ function was sustained for almost five days with consent from his family, and there were no signs that the organs were being rejected in the first 24 hours, according to a study published in Med today1.
Most procedures in which a pig organ is transplanted into a person — known as xenotransplantation — involve only a single organ. A small number of people have received pig organs, including hearts, kidneys, partial livers and lungs, and clinical trials in living people are under way in the United States and China. Until now, only parts of a pig liver have been transplanted into a person, says Xuyong Sun, a clinician scientist who led the latest procedure at the Second Affiliated Hospital of Guangxi Medical University in Nanning, China.
Transplanting pig kidneys and a liver in the same procedure is also unique, says Leonardo Riella, a physician scientist at Massachusetts General Hospital in Boston, who in 2024 led the team that first transplanted a pig kidney into a living person. Transferring multiple organs is more complex than moving one; procedures take longer, increasing the risk of complications, and people who need multiple transplants are often more seriously ill, he adds.
The study shows that multi-organ xenotransplants are possible, says Wayne Hawthorne, a surgeon and transplant researcher at the University of Sydney in Australia.
Multi-organ transplants are already performed with human organs, but there is a shortage of donor organs, which is why research teams are investigating the use of pig kidneys.
Complicated operation
The man who received the pig organs had severe chronic kidney disease and bleeding in his brain before doctors confirmed that his brain had died. His liver was healthy, so it was transplanted into a living person, says Sun.
The man received organs from a pig that had had six edits to its genome. Three human genes were added to reduce the risk of problems with blood clotting, and three pig genes were removed to prevent the organs being rejected.
Within 19 hours of the transplant, the pig liver began secreting bile and showed signs that it was functioning normally, the team reports. The man’s levels of the waste products creatinine and urea — which had been elevated because of his kidney disease — returned to normal after he received the pig kidneys, which suggests they were also functioning.
But 36 hours after the operation, the team noticed early signs that the pig organs were being rejected. For instance, the pig cells in the liver and kidneys were gradually being replaced by human cells, suggesting that the man’s immune system had detected that the organs were foreign. There were also small areas of tissue death and blood clotting in the pig liver.
The authors observed that the transplanted organs had raised levels of a type of immune cell called S100A12+, which is involved in inflammation. They suggest that these cells could be targeted with drugs to reduce the risk of long-term organ rejection.
