The News
Scientists have successfully transplanted a genetically engineered pig liver into a human for the first time
Chinese researchers inserted the liver, which was taken from a pig that had been genetically edited to remove proteins that can cause organ rejection, into the body of a clinically dead patient whose brain had stopped functioning. After 96 hours the patient showed no sign of organ rejection, and the transplanted liver’s blood and bile flow were both working appropriately, the researchers said.
The transplant was the “first of its kind in the world”, China’s Air Force Medical University said in a post on the social media platform WeChat.
Researchers in the United States have previously carried out xenogenic transplants — where an organ from one species is transferred to another — of gene-edited pig kidneys and hearts into clinically dead human patients.
SIGNALS
Xenotransplantation could help address the global organ shortage
Each year in China alone more than 500,000 people face liver failure, which can only be treated with a transplant. With a global shortage of viable livers for patients, scientists hope xenotransplantation can help fill the gap, with the South China Morning Post calling the Chinese transplant a “breakthrough that could help alleviate organ shortages.”
In the U.S., an estimated 17 people die every day while waiting for an organ transplant. “That someone has to die for someone to live is a broken paradigm,” a New York University doctor who has been researching xenotransplantation told CNN. “I think animals are the answer.”
Animal rights activists say xenotransplantation is unethical
Animal rights activists argue that harvesting organs from animals to transfer to people is morally wrong and could unintentionally transfer animal-borne diseases to humans. “Using pigs as a source of spare parts is dangerous to the human patients, deadly for the animals and may bring about the next pandemic,” Kathy Guillermo, senior vice president at People for the Ethical Treatment of Animals, told The New York Times. “Researchers need to focus on cleaning up the organ donation system and leave the animals alone.”
A 2020 study from the National Library of Medicine outlined these concerns and more, including the conditions animals raised for xenotransplantation would have to live in and questions about how to distribute the organs fairly once they’re harvested.
Animal liver transplants could offer a temporary detox or buy time
Despite recent progress, scientists have cautioned that liver transplants might only be a “short-term fix for people with liver failure,” according to the scientific journal Nature. While heart and kidney transplants could offer longer-term solutions, livers are difficult to transplant for extended periods. “Unlike the heart, which essentially functions as a pump, the liver performs many complex tasks” that are hard to replicate, including waste disposal and producing a wide range of proteins, the journal stated.
In trials on animals, SCMP reported, those that receive xenogenic liver transplants survive for a shorter time than those that receive hearts and kidneys. The Chinese researchers said that currently, xenogenic liver transplants are a good temporary alternative while patients wait for a human organ. And as the human liver is able to regenerate, a pig liver transplant could also provide a temporary detox after damage caused by alcohol or drug consumption, Nature reported.