The patient, who was not eligible for a human liver transplant, lived for nearly half a year after the procedure
The wonders of science never fail. There are breakthroughs constantly emerging emerging from the health and technology fields, and now, another world first has been recorded in the form of an animal to human transplant.
That is because medics have transplanted a pig liver into a human in what has been described as a “landmark” move and “pivotal step forward” that has ushered in a “new era”.
The patient, a 71-year-old man, lived for half a year after the procedure. The man’s own liver had irreversible scarring caused by a hepatitis B infection and liver cancer. He was not eligible for a human liver transplant as a result.
Never before has a liver from a genetically-modified pig been transplanted in a human for “therapeutic purposes”.
Two cases have previously been reported in brain dead patients as part of preparatory work.
Researchers said they have found that genetically modified pig livers “can support key metabolic and synthetic functions in humans,” as per the Journal of Hepatology.
So, how did it all happen? Well, 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 (xTMA).
Treatment resolved the xTMA, but despite this, the patient sadly 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 Dr 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.”
Dr 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, gene-editing technology, plus 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 US.
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 last year aged 62.
