A pig’s kidney transplanted by surgeons into a brain-dead man has continued to function normally for more than a month, a crucial step toward a procedure the New York team hopes to eventually perform on living patients.
The most recent experiment, which New York University Langone Health announced on Wednesday, represents the longest period of time a pig kidney has operated on a human, albeit a deceased one, and it is not yet complete. The kidney’s performance will be monitored for a second month.
“It looks even better than a human kidney,” Montgomery said on 14 July as he replaced a deceased man’s own kidneys with a single kidney from a genetically modified pig – and watched it immediately start producing urine.
Scientists across the country are in a race to learn how to use animal organs to save human lives, and bodies donated for research provide an exceptional opportunity for practice. More than 100,000 patients are on the transplant list in the United States, and thousands die each year while waiting.
The possibility that pig kidneys could one day help alleviate a severe shortage of transplantable organs convinced the family of 57-year-old upstate New York resident Maurice “Mo” Miller to donate his body for the experiment.
For decades, attempts to perform animal-to-human transplants have failed because the human immune system attacks foreign tissue. Now, scientists are utilizing genetically modified pigs whose organs more closely resemble human organs.
Balancing Possibilities and Realities: Ethical and Practical Aspects of Prolonged Testing
The NYU experiment is one of a series of initiatives designed to expedite the initiation of such clinical trials. Also on Wednesday, the University of Alabama at Birmingham (UAB) announced another significant achievement: two pig kidneys functioned normally for seven days inside another donor body.
Aside from producing urine, the kidneys perform a variety of other functions in the body. Dr. Jayme Locke of the University of Alabama at Birmingham reported lab tests on the performance of the gene-modified pig organs in the journal Jama Surgery.
She said the weeklong experiment demonstrated they could “provide life-sustaining kidney function.”
Montgomery was removing both kidneys from the donated body as they raced back to NYU, so there would be no doubt if the soon-to-arrive pig version was working. One pig kidney was transplanted, while the other was saved for comparison after the experiment was completed.
How long should these tests last? According to Alabama’s Locke, that is not clear, and among the ethical concerns are how long a family can be comfortable and whether it adds to their grief.
The donor body’s stability is another factor in the decision because maintaining a brain-dead person on a ventilator is challenging.
In her own experiment, the donated body was stable enough that if the study wasn’t required to end after a week, “I think we could have gone much longer, which I think offers great hope,” she said.
Dr. Muhammad Mohiuddin of the University of Maryland cautions that it is unclear how closely a deceased body will mimic a live patient’s reactions to a pig organ but that this research educates the public about xenotransplantation so that “people will not be shocked” when the time comes to try again in the living.
Source: The Guardian