A newly published report shows that the lungs of a genetically modified pig were brain-deadly implanted and functioned for nine days.
There has been recent success in transplanting pig kidneys and hearts into humans, and this is considered to be the first attempt to transplant pig lungs into humans. Doctors hope that one day this will become an option for people in need of organs, but experts say it won’t be time soon.
The authors of the first affiliated hospital at Guangzhou Medical University in Ching did not identify patients in the study, but he is said to be a 39-year-old man who was declared brain dead after a cerebral hemorrhage. After obtaining consent from the man’s family, the doctor implanted a pig’s lungs into his body. The findings were published in Nature Medicine on Monday.
With human-to-human or animal-to-human transplants (also known as xenografts), doctors carefully monitor infection and rejection.
Patients were given several medications to reduce the risk of infection and rejection. The lungs themselves were also undergoing six gene editing, and donor pigs were kept in very clean and strictly controlled areas throughout their lifetimes.
In this study, researchers reported that they did not see any immediate signs of rejection after implantation, but found problems one day later.
A blood flow problem caused extensive swelling throughout the man’s body, as a liquid potentially accumulated in his tissues. In addition to helping a person breathe, the lungs play a role in blood circulation.
There were some signs of partial recovery a few days after the transplant, but despite all caution, the doctor saw signs that the man’s body was beginning to reject his organs.
At the request of the man’s family, the doctors completed the experiment.
“This study shows the feasibility of xenografting of the lungs from pigs to humans, but there remain substantial challenges associated with organ rejection and infection,” the researchers write in a new study. They concluded that more research is needed before the treatment can be repeated again in clinical trials.
The world needs donated organs. In the US alone in 2023, all organ transplant wait lists were twice as many times complete.
Last year there was more 48,000 transplants In the US, over 103,000 people were on the waiting list. Approximately 13 According to the Federal Agency for Health Resources and Services, or the HRSA, people in the United States die every day waiting for a transplant.
Pig valves have been implanted in humans for the past 30 years. Although organs are difficult, doctors have seen limited success with genetically modified pig hearts and pig kidneys. They also experimented with genetically modified pig livers, but at least so far less successful.
The most successful so far is Tim Andrews of Massachusetts, who lives with the kidneys of a genetically modified pig that was transplanted at Massachusetts General Hospital in January.
Experts say there are ways to go before pig lung transplants show many success.
“No one will sign up for a nine-day lung transplant,” said Dr. Adam Grisemer, a transplant surgeon who is a senior member of the xenotransplant team at NYU Langone’s Transplant Institute, who was not involved in the new study.
Griesemer said in previous experiments that pig lung transplants into other animals showed similar results.
“I think it’s very important to do these studies because we can’t assume that animal models fully reflect what happens to human recipients,” Griesmer said.
Chinese researchers said some have conducted the study because of the “transformational potential” of xenotransplants.
Dr. Ankit Bharat, director of the Northwest Medical Canned Chest Research Institute, found the study interesting, but added that he believes that pig-to-human lung transplants will not occur anytime soon.
“We will learn something from now on, but we are not entirely sure this opens the door to truly bringing to great challenges.
Lungs are much more complicated to transplant than organs like kidneys, he said.
The lungs play an important role in hemofiltration, temperature regulation, platelet production, pH balance, and immune defense, and have metabolic and endocrine functions. Also, unlike the kidneys and heart, the lungs are exposed to external elements such as viruses and bacteria.
They are so large and covered with proteins that aid in immune defense, it is difficult to avoid the body’s instincts to reject something foreign, even if you have a lung transplant from another person, Bharat said.
“It’s a difficult problem to solve. Even human organs don’t really solve it,” he said. “So we’re just adding another complex layer of pig antigens that could become another problem.”
Researchers behind the new study suggested that the male body showed no signs of immediate rejection of the pig’s lungs, but Bharat is less sure after seeing the shared x-ray and CT images.
“There’s a lot of damage,” Bharat said. “I’m not sure if I’m completely certain there’s no superacute rejection.”
Bharat believes that advances in the use of human stem cells than transplants can be promising, at least when it comes to lung transplantation.
Griesemer said that stem cell therapy can be used to replace human cells with pig cells, as well as stem cell therapy, as well as studies that use pig lungs as scaffolds.
“In a sense, the cells are human, but the structure is from pigs, so it’s not actually a xenograft,” Griesmer said. “It’s another possibility for people who need a lung transplant, how medical technology can solve this problem.”
Recent advances in cloning and gene editing have led a small number of institutions to better understand infection control and to breakthroughs in transplanting other pig organs.
