World’s first pig-to-human liver transplant keeps patient alive for 171 days

In what researchers are calling a "landmark" in medical science, surgeons implanted a genetically engineered pig liver into a living human patient, marking the first reported case of auxiliary liver xenotransplantation.

As documented in the Journal of Hepatology, the patient survived for 171 days, showing that a pig liver can perform essential functions in a human body - but also highlighting the serious challenges that remain.

According to the World Health Organization, thousands of people die waiting for a liver transplant every year. In China alone, hundreds of thousands suffer from liver failure, yet only about 6,000 receive a transplant.

Scientists hope this practice could eventually help bridge the gap and provide life-saving organs to those in need.

'A pivotal step forward,' though challenges remain

The patient, a 71-year-old man with liver disease caused by hepatitis B and liver cancer, could not undergo conventional surgery or receive a human liver.

Doctors implanted a liver from a specially engineered Diannan miniature pig. The pig’s liver had ten gene changes designed to reduce rejection by the human immune system and make blood clotting safer.

For the first month, the transplant worked remarkably well. The liver produced bile and important blood-clotting proteins with no signs of immediate rejection.

But complications arose on day 38 when the patient developed a serious condition called xenotransplantation-associated thrombotic microangiopathy (xTMA), linked to immune reactions and blood vessel damage.

Treatments helped manage the condition, but the patient later suffered repeated internal bleeding and died on day 171.

“This case proves that a genetically engineered pig liver can function in a human for an extended period,” explained lead investigator Beicheng Sun.

“It is a pivotal step forward, demonstrating both the promise and the remaining hurdles, particularly regarding coagulation dysregulation and immune complications, that must be overcome.”