Researchers said medics have successfully transplanted a pig liver into a human in a world first. The patient, a 71-year-old man, lived for almost half a year after the procedure.

The man’s own liver had irreversible scarring caused by a hepatitis B infection and liver cancer. As a result, he was not eligible for a human liver transplant.

This is the first time that a liver from a genetically-modified pig has been transplanted in a human for “therapeutic purposes”.

Two cases have previously been reported in brain-dead patients as part of preparatory work.

Writing in the Journal of Hepatology, researchers reported that genetically modified pig livers can support key metabolic and synthetic functions in humans.

Scientists in China described how they implanted an “auxiliary graft” from a genetically modified Diannan miniature pig; these gene edits were designed to enhance organ compatibility.

For the first month, medics found that the graft functioned effectively.

But on day 38, the graft was removed following complications linked to the transplant, a condition called xenotransplantation-associated thrombotic microangiopathy.

Researchers reported that treatment resolved the xTMA, but in spite of this, the patient died 171 days after the transplant.

“This case proves that a genetically engineered pig liver can function in a human for an extended period,” said lead investigator Beicheng Sun, from the First Affiliated Hospital of Anhui Medical University in China’s Anhui Province. “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.”

In an accompanying editorial, Heiner Wedemeyer, co-editor of the journal, said, “This report is a landmark in hepatology; it shows that a genetically modified porcine liver can engraft and deliver key hepatic functions in a human recipient.

“At the same time, it highlights the biological and ethical challenges that remain before such approaches can be translated into wider clinical use. Xenotransplantation may open completely new paths for patients with acute liver failure, acute-on-chronic liver failure, and hepatocellular carcinoma. A new era of transplant hepatology has started.”

When a human receives an organ, tissue, or cells from an animal, it is known as a xenotransplant.

Pigs are the most promising donor animals due to the availability of pig organs, gene-editing technology, and their size and similarities to human organs. Overcoming the rejection of pig organs by the human immune system has been a complex challenge for more than four decades.

But gene-editing technology and new techniques to suppress the immune system have shown promise in several recent experiments. The first person in the world to have a heart transplant from a genetically modified pig was David Bennett.

The operation took place in 2022, and the 57-year-old died two months after the procedure, which took place at the University of Maryland Medical Centre in the U.S.

The first recipient of a genetically-modified pig kidney transplant died nearly two months after he underwent the procedure. Richard Slayman had the transplant at Massachusetts General Hospital in 2024 at the age of 62.

(dpa/NAN)