Pig Kidney Transplant Marks Record 271 Days

A kidney transplanted from a pig has functioned within a patient for 271 days, setting a new record and offering considerable hope. This xenotransplant, performed at Mass General Brigham hospital, served as a crucial bridge for Tim Andrews until a donor organ became available. The procedure underscores the potential of using organs from other species to address the severe shortage of human transplants.

In the United States, approximately 100,000 individuals are on the kidney transplant waiting list, with only 25,000 transplants occurring annually. Andrews, facing a seven-year wait for a human kidney and experiencing the challenges of dialysis, viewed the pig transplant as a vital "light at the end of the tunnel."

Pigs are extensively researched for xenotransplantation due to their organ size compatibility. However, extensive genetic modifications to their organs are essential to prevent immediate immune rejection by the human body. These modifications aim to "humanize" the pig organs, reducing immune system attacks and preventing viral transmission.

Andrews, aged 66, received the transplant on January 25, 2025. The pig kidney initially performed well, but after approximately six months, its blood vessels began to show damage, leading to inflammation and eventual failure. While immune rejection was managed through medication adjustments, the precise reason for the later failure remains unclear. The case, published in The Lancet, illustrates both the promise and the challenges that remain in clinical kidney xenotransplantation.