It was the longest time a genetically altered pig organ had ever worked inside a living human being, even if it was a dead one. Scientists learned valuable lessons by testing pig kidneys on the dead. They will share these with the Food and Drug Administration in order to test them in the future. Two months is not a long time to keep a kidney this healthy. That gives you a lot of confidence” for next attempts.
Montgomery, himself a recipient of a heart transplant, sees animal-to-human transplants as crucial to ease the nation’s organ shortage. More than 100,000 people are on the national waiting list, most who need a kidney, and thousands will die waiting.
So-called xenotransplantation attempts have failed for decades — the human immune system immediately destroyed foreign animal tissue. What’s new: Trying pigs genetically modified so their organs are more humanlike.
Surgeons remove a gene-edited transplanted pig kidney from the body of Maurice “Mo” Miller at NYU Langone Health in New York on Sept. 13, 2023.
Some experiments on dead bodies prevented an immediate immune response but did not shed light on the more common type of rejection which can take up to a month. The FDA gave Montgomery’s team a list of questions about how pig organs perform their jobs compared to human ones. And the FDA gave Montgomery’s team a list of questions about how pig organs really perform their jobs compared to human ones.
Montgomery gambled that maintaining Miller’s body on a ventilator for two months to see how the pig kidney worked could answer some of those questions.
“I’m so proud of you,” Miller’s sister, Mary Miller-Duffy, said in a tearful farewell at her brother’s bedside this week.
“This has been quite the journey,” Miller-Duffy said as she and her wife Sue Duffy hugged Montgomery’s team.
On July 14, shortly before his 58th birthday, surgeons replaced Miller’s own kidneys with one pig kidney plus the animal’s thymus, a gland that trains immune cells. The kidney was working well for the first month. The biopsy confirmed that the kidney was showing signs of rejection, allowing doctors to determine if treatment was possible. Sure enough, the kidney’s performance bounced back with a change in standard immune-suppressing medicines that patients use today.
“We are learning that this is actually doable,” said NYU transplant immunologist Massimo Mangiola.
The researchers checked off other FDA questions, including seeing no differences in how the pig kidney reacted to human hormones, excreted antibiotics or experienced medicine-related side effects.
“It looks beautiful, it’s exactly the way normal kidneys look,” Dr. Jeffrey Stern said Wednesday after removing the pig kidney at the 61-day mark for closer examination.
The next steps: Researchers took about 180 different tissue samples — from every major organ, lymph nodes, the digestive tract — to scour for any hints of problems due to the xenotransplant.
Experiments in the deceased cannot predict that the organs will work the same in the living, cautioned Karen Maschke, a research scholar at the Hastings Center who is helping develop ethics and policy recommendations for xenotransplant clinical trials.
But they can provide other valuable information, she said. The researchers can also use the samples to find out if the organs will work the same in the living as they did when the pigs were alive. Karen Maschke, a research scholar at the Hastings Center, who is helping develop ethics and policy recommendations for xenotransplant clinical trials, said that the deceased pigs cannot be used to predict how the organs will function in the living. We need to act.” All content is the sole responsibility of The Associated Press.