Pig kidney transplanted to brain-dead man lasts more than a month

A pig kidney transplanted to a brain-dead man by surgeons has continued to function normally for more than a month – a critical step towards an operation that the New York team hopes to eventually try on living patients.

The latest experiment, announced on Wednesday by NYU Langone Public Health, finds the longest lifespan of a human pig kidney, albeit deceased, has yet to end, according to The Guardian. Researchers will monitor kidney function for a second month.

“Will this organ really work like a human? So far, everything looks the way it is,” Dr. Robert Montgomery, director of the NYU Langone Transplant Institute, told The Associated Press.

“It looks even better than a human kidney,” Montgomery said on July 14, after replacing the deceased man’s kidneys with a single genetically engineered pig’s kidney — and watching it immediately begin to urinate.

Scientists across the country are eager to learn how to use animal organs to save human lives, and organs donated for research are a wonderful rehearsal. More than 100,000 patients are on the national transplant list, and thousands die waiting each year, the Associated Press notes.

The possibility that pig kidneys could one day help deal with a severe shortage of transplantable organs convinced the family of 57-year-old Maurice “Moe” Miller of upstate New York to donate his body for the experiment.

“I had my doubts about that,” his sister Mary Miller-Duffy told the AP. “But he liked helping others, and I think that’s what my brother would like. So I offered them my brother. He will be written about in medical books and he will live forever.”

Attempts to transplant organs from an animal to a human have failed for decades as people’s immune systems attacked foreign tissue, the Associated Press emphasizes. Researchers are now using genetically modified pigs to make their organs better match human bodies.

Last year, with special regulatory approval, University of Maryland surgeons transplanted a gene-edited pig heart in a last-ditch effort to save a dying man. He lived only two months before the organ failed for reasons that are not fully understood, but which provide lessons for future attempts.

Now the US Food and Drug Administration is considering whether to allow several small but rigorous trials to transplant a pig heart or kidney into volunteer patients.

The NYU experiment is one of a series of developments aimed at accelerating the start of such clinical trials. Also on Wednesday, the University of Alabama at Birmingham (UAB) reported another major success – a pair of pig kidneys functioned normally inside another donor organ for seven days.

The kidneys perform a wide range of functions in the body, in addition to the production of urine, recalls the Associated Press. In the journal Jama Surgery, UAB transplant surgeon Dr. Jaime Locke reported on laboratory tests documenting the work of genetically modified pig organs. She said the week-long experiment demonstrated that they could “provide life-sustaining kidney function.”

These experiments are critical to answering other remaining questions “in a setting where we’re not putting anyone’s life in danger,” said Montgomery, an NYU kidney transplant surgeon who has also had a heart transplant himself — and is keenly aware the need for a new source of organs.

The operation itself is not much different from the thousands he has performed before, “but somewhere deep down you realize the enormity of what you are doing … you realize that this can have a huge impact on the future of transplantation,” Montgomery said.

The operation was carefully planned in time. Early that morning, doctors Adam Griesemer and Jeffrey Stern flew hundreds of miles to a facility where Virginia-based Revivicor Inc keeps genetically engineered pigs and removed kidneys that lack a gene that would cause immediate destruction by the human immune system.

As they raced back to NYU, Montgomery removed both kidneys from the donor body so there was no doubt that the pork version would soon arrive. One pig kidney was transplanted, the other was kept for comparison at the end of the experiment.

“You’re always nervous,” Grisemer said. Seeing it all start so quickly, “I experienced a lot of thrills and a huge sense of relief.”

How long should these experiments last? Locke, of Alabama, said it’s unclear, and ethical questions include how long the family is comfortable and whether it exacerbates their grief. Since it is difficult to keep a brain-dead person on a ventilator, the decision also depends on how stable the donor body is.

In her own experiment, the donor body was fairly stable, and if the study didn’t have to end in a week, “I think we could have lasted a lot longer, which I think is very encouraging,” she said.

Dr. Muhammad Mohiuddin of the University of Maryland warns that it’s unclear how closely a deceased body will mimic a live patient’s response to a pig organ, but this study educates the public about xenotransplantation so “people won’t be shocked” when it comes time to try again in a living patient.