A genetically modified kidney from a pig named Wilma has kept a 66-year-old man with kidney failure alive for a record nine months. This procedure successfully acted as a “bridge” to a human transplant, a world first.
Tim Andrews, who had end-stage kidney disease caused by type 2 diabetes, faced a low chance of receiving a human kidney within five years. Surgeons in the US transplanted the kidney from a Yucatan miniature pig, genetically engineered to be compatible with his immune system.
The pig kidney kept Mr Andrews off dialysis for 271 days, the longest period recorded for such a transplant. After the pig kidney began to fail, he received a kidney from a deceased human donor. Details of this breakthrough were published in The Lancet medical journal.
The team behind the transplant at Mass General Brigham noted that Mr Andrews' case represents the longest dialysis-free survival following pig kidney xenotransplantation in a living human. They also stated it was the world’s first transition to human kidney transplantation.
Damage developed in the pig kidney’s blood vessels after approximately six months, leading to organ failure and its removal nine months post-transplantation. After several months back on dialysis, Mr Andrews received a human kidney, which has functioned well during six months of follow-up. No new antibodies against human tissue or pig viruses were detected.
The team cautioned that this was a single patient case without a comparison group, and the outcome reflected careful patient selection and intensive specialist care. Further clinical trials are needed, but the success opens the door for pig kidney transplants to serve as a bridge for others awaiting human organs.