For the first time in medical history, a patient who had received a genetically modified pig kidney transplant has successfully received a human organ transplant. Sixty-six-year-old Tim Andrews lived for 271 days without dialysis before receiving a human kidney. A study published in The Lancet confirms that xenotransplantation (the transplantation of an animal organ into a human) could provide patients with an effective alternative to dialysis.
One of the most pressing challenges in transplantation today is the shortage of donor organs. According to Leonardo Riella, Medical Director at Massachusetts General Hospital, transplantation is the best option for patients with end-stage organ failure, but the number of available donors is limited. “Xenotransplantation could help fill this gap — initially as a bridge while patients wait for a human organ, and eventually as an independent, definitive therapy,” Riella explains.
The first transplant of a genetically modified pig kidney into a human was performed in 2024, but that patient survived for only 52 days. Until now, no study had demonstrated that an animal organ could function for more than two months and keep a patient alive until a human donor organ became available. The newly modified organs were developed jointly by biotechnology company eGenesis and scientists at Harvard Medical School.
Tim Andrews’ body successfully accepted the pig kidney, and the organ began functioning. At an early stage, doctors detected a rejection response, which they quickly controlled with medication. About six months after the transplant, the patient developed an infection, prompting doctors to reduce his immunosuppressive therapy. This ultimately led to microvascular injury, inflammation, and loss of function in the xenograft.
After the pig kidney stopped functioning, the patient received a human kidney transplant. No signs of sensitization or rejection were observed following the transplant. According to the researchers, the case demonstrates the enormous potential of xenotransplantation. Studying the inflammatory processes that developed in the animal organ could also help specialists improve future clinical trials.
