Genetically edited pig kidney sustains patient for record 271 days, serving as first bridge to human transplant
核心洞察
A 66-year-old man with end-stage kidney disease (搜索) lived dialysis-free for a record 271 days with a genetically edited pig kidney before receiving a human transplant.
The case represents the longest dialysis-free survival following porcine kidney xenotransplantation in a living human and the first transition to human kidney transplantation.
The pig kidney, from a Yucatan miniature pig with 69 genomic edits, functioned immediately and showed no pig pathogen transmission or sensitization against human tissue.
A genetically modified kidney from a pig named Wilma kept a 66-year-old man with kidney failure alive for a record nine months and successfully acted as a "bridge" to a human transplant in a world first. Tim Andrews was seriously ill with end-stage kidney disease (搜索) caused by type 2 diabetes (搜索) and had only a 9% chance of receiving a human kidney within five years, against a more than 40% risk of dying or being removed from the waiting list.
Details of the breakthrough, which offers hope to millions of people whose kidneys have failed, were published in the Lancet medical journal. The team behind the transplant at Mass General Brigham (搜索), a non-profit, integrated academic healthcare system in Massachusetts, said Andrews successfully lived with the genetically edited kidney for 271 days before receiving a human kidney from a donor.
A Record-Breaking Xenotransplant
Transplanting genetically engineered pig organs has long been proposed as a solution to the organ shortage. However, the first pig kidney transplant into a living person, in 2024, ended after 52 days when the patient died from unrelated heart problems, and no previous studies had documented xenograft survival beyond two months, according to the Lancet.
Andrews received the genetically engineered pig kidney under an FDA Expanded Access Investigational New Drug application. He was then monitored for kidney function, rejection, antibody development, and potential pig-to-human infection. The kidney functioned immediately. An early episode of T-cell-mediated rejection resolved with treatment, no pig pathogen transmission was detected, and the patient was able to go without dialysis for 271 days.
His case represents the longest dialysis-free survival following pig kidney xenotransplantation in a living human, and the world's first transition to human kidney transplantation, the team said.
Genetic Engineering and Clinical Course
Before the transplant in January 2025, Wilma the pig had received 69 edits to her genome. Some of these were designed to dodge viruses that might pose a risk to humans, while others made the organ more compatible with humans, reducing the odds of immune rejection.
After roughly six months, immunosuppression was reduced in the setting of infection. The xenotransplant subsequently developed microvascular injury and inflammation that progressed to organ failure, and the kidney was removed nine months after transplantation. After several months back on dialysis, Andrews received a kidney from a dead human donor, which worked well during six months of follow-up, according to the Lancet.
There were no new antibodies against human tissue detected, indicating the pig kidney had not made it harder for the human kidney transplant to work successfully. No pig viruses or other pig pathogens were detected at any point.
Addressing the Organ Shortage
Kidney transplantation provides the best survival and quality of life for patients with end-stage kidney disease (搜索), but global demand for human organs far exceeds supply.
"The organ shortage is the greatest crisis we have right now in transplantation," said Dr Leonardo Riella, of the Center for Transplantation Sciences and the Division of Nephrology at Mass General Brigham (搜索). "We know that the best treatment option for patients with end-stage kidney disease (搜索) who have developed renal failure is transplantation, but we simply don't have enough human organs to transplant in a timely manner."
"Our vision is that xenotransplantation could help address this gap – initially as a bridge to get patients off dialysis while they wait for a human donor kidney, and potentially, as we establish long-term safety and durability, as a destination therapy in its own right."
Implications and Limitations
The findings illustrate both the promise and areas for improvement for xenotransplants as a bridge for patients awaiting human kidneys. Importantly, the microvascular injury to the porcine kidney has implications in the development of immunosuppressive strategies, donor genetic engineering, and monitoring in future clinical transplantation studies.
The team cautioned that this was a single patient with no comparison group, and that the outcome reflected careful patient selection and intensive specialist care that may not be available elsewhere. Further clinical trials such as the one Andrews participated in will be needed, but the success opens the door to pig kidney transplants as a bridge for other people facing long waits for a human kidney.
"Mass General Brigham (搜索) has a strong history of kidney transplantation, beginning with the first-ever live donor kidney transplant in 1954," said senior author Tatsuo Kawai, MD, PhD, director of the Legorreta Center for Clinical Transplantation Tolerance at Mass General Brigham. "Our findings continue that history by both furthering what we know about xenotransplants and generating knowledge that could be applied to other organ transplantation work."
"The patients are the true pioneers here," Riella said. "By stepping forward and being willing to participate in these early stage studies, they are advancing the science. Without their trust and courage, we would not be able to do what we do."