World's longest pig kidney transplant in human fails after 4 months

After 4 months, the world's longest pig kidney transplant has failed. 53 year old Towana Looney received a kidney from a gene-edited pig on 25 November 2024, had it removed after the organ suddenly stopped functioning. The pig organ was removed on April 4.

"The 4 months and 9 days Looney spent with the kidney set a new record for a pig organ in a human, but it is yet another setback for the long-struggling field known as xenotransplantation," Science reported.

“I’m so grateful to have been given the opportunity to be part of this incredible research,” Looney told the media. “Though the outcome is not what anyone wanted, I know a lot was learned from my 130 days with a pig kidney—and that this can help and inspire many others in their journey to overcome kidney disease.”

Looney was one of the two recipients of kidneys from pigs after the only kidney she had failed; she had donated her another kidney to her mother. In late March, her immune system began to reject the organ. "With the help of immunosuppressive drugs, Looney was doing so well with the pig kidney that she returned to her home in Alabama in February. But for reasons that are still being investigated, her immune system began to reject the organ in late March," the report adds.

While the exact cause is not known, her medical team says it might be due to lowering of her immunosuppression regimen to treat an infection unrelated to the pig kidney.

Why is pig’s kidney used for transplantation?

Pigs are often used for xenotransplantation because their organs are similar in size and function to human organs. Xenotransplantation is the process of transplanting organs, tissues, or cells from one species to another—most commonly from animals to humans. It offers a potential solution to the global shortage of human donor organs. Despite its promise, xenotransplantation poses significant challenges, including the risk of organ rejection and the potential transmission of animal viruses. As science progresses, xenotransplantation could become a life-saving alternative for patients waiting for transplants, but ethical and safety concerns remain.

World's first recipient of pig kidney died due to heart attack
Rick Slayman was the first man to receive a kidney transplant from a genetically engineered pig. Rick died in 2024 due to an “unexpected cardiac event.” There was no sign that his body rejected the pig's organ.