Genetically modified pig kidney still functioning 32 days after transplant into brain dead man

Surgery marks major milestone in field of xenotransplantation

A genetically modified pig kidney is still functioning inside the body of a brain dead man more than a month after it was surgically transplanted, surgeons at New York University Langone Health announced on Wednesday.

The surgery marks a major milestone in the field of xenotransplantation, the practice of using non-human cells or organs to treat medical conditions.

“There are simply not enough organs available for everyone who needs one,” Dr Robert Montgomery, director of the NYU Langone Transplant Institute, said in a news release.

Doctors implant a pig kidney into the body of Maurice Miller in July 2023 (NYU Langone Health)

He performed the July surgery, the fifth such undertaken at NYU.

“Too many people are dying because of the lack of available organs, and I strongly believe xenotransplantation is a viable way to change that,” he added.

The pig kidney was genetically modified to remove a protein that the human immune system rejects, and was implanted into the body of 57-year-old Maurice “Mo” Miller, who died of an undiagnosed brain tumor prior to the experiment.

The NYU team also inserted a pig’s thymus gland, which helps train the immune system, to further aid the procedure.

The foreign kidney continues to carry out normal functions like filtering toxins and concentrating urine.

Miller’s family volunteered his body for the experiment at his wishes.

“I struggled with it,” his sister, Mary Miller-Duffy, told the Associated Press, but said her brother liked helping others.

Maurice “Mo” Miller (Miller Family / NYU Langone Health)

“I think this is what my brother would want. So I offered my brother to them.”

“He’s going to be in the medical books, and he will live on forever,” she added.

The news of the New York pig kidney transplant came the same day that University of Alabama researchers announced they had succesfully transplanted a pig kidney with 10 genetic alterations that continued to function normally for a week, before the experiment was concluded at the wishes of the patient’s family.

“This is the first time in history that anyone has been able to show a genetically modified pig kidney is able to maintain life-sustaining kidney function,” said Jayme E Locke, lead author of the research, told The Washington Post.

At a given time, more than 100,000 people in the US are waiting for an organ transplant, the vast majority of them seeking a kidney, according to federal data.

Many die or become too sick to receive a transplant before they are eligible.

Surgeons have previously transplanted a pig heart into a living man, David Bennett, who died after two months.

The FDA is considering whether to allow studies of pig heart and kidney transplants in volunteer patients.