A pig kidney transplanted into a brain-dead man continued to function for two months, marking the longest time a non-human organ has survived in a human.
The procedure, performed on July 14, implanted the kidney in Maurice ‘Mo’ Miller, 58, whose body was donated by his family after he was declared dead by neurological criteria and kept with his heart beating with respiratory support.
The experiment ended Wednesday when doctors removed the genetically modified organ and Miller’s sister said her final goodbyes.
“I’m so proud of you,” Mary Miller-Duffy said as she said a tearful goodbye at her brother’s bedside.
The surgeons at NYU Langone Health, who conducted the experiment, determined no differences in how the pig kidney reacted to human hormones, excreted antibiotics, or experienced drug-related side effects.
It is the latest in a series of developments that are renewing hope for animal-to-human transplants, or xenotransplants, after decades of failure when people’s immune systems attacked foreign tissue.
In a previous attempt, the organ only lasted 72 hours before being rejected.
The experiment was carried out on Maurice ‘Mo’ Miller, 58, whose body was donated by his family after he was declared dead by neurological criteria and kept on a beating heart and on respiratory support.
The pig kidney suffered a modification of a single gene: a sugar molecule on the surface of pig cells that can cause the human immune system to attack the pigs’ organs.
Dr Jeffrey Stern, who was involved in the research, said: “It looks beautiful, it’s exactly what normal kidneys look like.”
The statements were made after the kidney was removed for further examination.
Dr. Robert Montgomery, the transplant surgeon who led the experiment, told The Associated Press: “It’s a combination of excitement and relief.
‘Two months is a long time to have a pig kidney in such good condition. That gives you a lot of confidence for the next attempts.
Montgomery, who also received a heart transplant, sees animal-to-human transplants as crucial to alleviating the country’s organ shortage.
More than 100,000 people are on the national waiting list, most of whom need a kidney, and thousands will die waiting.
Montgomery has performed thousands of transplants, but always on human beings with human organs.
“Somewhere in the back of your mind is the enormity of what you’re doing…recognizing that this could have a huge impact on the future of transplantation,” Montgomery said.
Surgeons removed the pig kidney (pictured) on Wednesday and found it was still in excellent condition.
Next steps: The researchers took around 180 tissue samples (from all major organs, lymph nodes and digestive tract) to look for any signs of problems due to the xenotransplantation.
Experiments on the deceased cannot predict that organs will function the same in the living, cautioned Karen Maschke, a Hastings Center researcher who helps develop ethical and policy recommendations for xenotransplantation clinical trials.
The mission began early on the morning of July 14 when doctors Adam Griesemer and Jeffrey Stern flew hundreds of miles to a facility where Virginia-based Revivicor houses genetically modified pigs to recover kidneys that lack a gene that would trigger destruction. immediate by the human immune system.
The team then raced to New York just as Montgomery was removing Miller’s kidneys.
One of the animal’s organs was used in the experiment and the other was saved for comparison when the research ends next month.
Toby Coates, a professor of medicine at the University of Adelaide who was not involved in the experiment, said: “This case represents one of the first functional kidney transplants from a pig to a human and shows proof of principle that the organs from a genetically modified animal can replace human kidney function for a week without rejection and using conventional kidney transplant drug therapy.
“I’m so proud of you,” said Mary Miller-Duffy (right) as she said a tearful goodbye at her brother’s bedside.
Miller is pictured as a child with his sister Mary.
“The key advance here is the genetic deletion of four porcine genes that have previously been shown to be a barrier to cross-species transplant success, and the insertion of six human genes that prevent clotting and ‘humanize’ the pig kidney so that it can be look more like a human (the 10 genes of the modified donor pig). ‘
In 2022, some 26,000 people received a kidney transplant. Meanwhile, nearly 808,000 people in the United States have end-stage renal disease.
This static likely helped convince Miller’s family to donate his body, as they were initially reluctant.
“I had trouble with it,” his sister, Mary Miller-Duffy, told the AP. But she liked helping others and “I think this is what my brother would want.” So I offered them my brother.’
“It will be in the medical books and will live forever,” he added.