Surgeons in China have successfully transplanted a genetically modified pig liver into a living patient for the first time. The 71-year-old patient survived for 171 days after the operation. A few months earlier, surgeons had successfully transplanted a pig liver into a brain-dead patient.
According to CNN, the surgery was performed on a 71-year-old man who suffered from cirrhosis of the liver and a large, inoperable tumor in his liver. Since no suitable human donor could be found, a pig liver transplant was considered the only remaining option to save his life.
The procedure, called an “allograft,” has always been one of the biggest challenges in the field due to the complexities of the liver. For the procedure, surgeons used the liver of a miniature pig that had been modified with 10 genetic edits to reduce the risk of rejection by the human immune system. Instead of completely replacing the patient’s liver, they placed the pig liver as a “helper liver” alongside the remaining part of the patient’s own liver.
Immediately after the transplant, the pig's liver began to function, turning red and producing bile. For 38 days, the animal organ performed the patient's vital liver functions. During this time, there were no signs of acute rejection, and even the patient's remaining liver function improved.
But after about a month, the patient developed a serious complication called xTMA, in which microscopic blood clots damage blood vessels. On day 38, doctors decided to remove the pig's liver, given that the patient's own liver had recovered enough to function normally.
The patient continued to live after the operation, but on day 171, he died of gastrointestinal bleeding (a complication that occurred after the pig's liver was removed).
The most important message of this research is the proof of concept that genetically modified pig livers can work in humans. “This transplant mainly introduces new perspectives and ideas... A pig liver gives us completely new opportunities, and this could be promising for our patients,” Chinese doctors say.
This means that in the future, pig livers could be used to keep patients with acute liver failure alive for weeks or months, either while their own livers recover or until a suitable human donor is found. This could save the thousands of lives that die each year on the transplant waiting list.
Source: Digiato - Azad Kabiri