Patients with severe liver disease could one day be kept alive with livers transplanted from pigs, scientists say. A team in China successfully transplanted the liver from a miniature pig that had been genetically modified to prevent rejection into a brain-dead human.
Observing the organ’s function for 10 days, they found that the liver was able to produce bile and albumin. The pig liver was connected alongside the patient’s own liver with no signs of their immune system attacking it. The experiment was terminated after 10 days at the request of the patient’s family.
Researchers at another Chinese hospital last year reported that they had transplanted a pig liver into a living patient with liver cancer.
However, this team is thought to be the first in the world to publish their peer-reviewed results in a scientific journal, Nature.
Professor Lin Wang, a doctor at Xijing Hospital of the Fourth Military Medical University in north-west China, said the result was a “great achievement” and could pave the way for pig livers to be used to treat patients with advanced liver disease.
This could involve connecting a pig liver to support the patient’s own partially functioning organ.
Prof Wang said: “It is our dream to make this achievement but currently we could not see whether the pig liver could support a patient with severe liver failure.
“We do not know the exact time a pig liver could support the human body because our current investigation was for 10 days.”
The amount of bile and albumin produced by the transplanted pig liver was less than would be expected for a human bod.
Pig organs are being studied as a possible solution to lengthy transplant waiting lists dye to their compatible physiological functions and size. Porcine hearts and kidneys have previously been transplanted into humans.
Prof Wang explained that the liver has proved “a huge obstacle…because the function of the liver is so complicated”.
He added: “The heart is just a pump to pump blood around the whole human body and the major function of the kidney is to produce urine.
“The liver has so many functions, to make cytokines, produce albumin and to modulate the immune system. This is the first time we have tried to unravel whether the pig liver could function well in a human body.”
The transplant follows more than 10 years of research into this process on animals. The Xijing team also carried out the first pig-to-monkey liver transplant in 2013.
Rafael Matesanz, founder of the National Transplant Organisation in Spain, said: “This is the world’s first case of a transplant of a genetically modified pig liver into a brain-dead human.
“The ultimate goal of the experiment was not to achieve a standard liver transplant, but to serve as a ‘bridge organ’ in cases of acute liver failure, while awaiting a human organ for a definitive transplant.”
Mr Matesanz said the procedure was “successful for its intended purpose” and that similar transplants could be carried in living organisms “in the near future”.