Pig-to-human transplants come step closer with new test

Scientists temporarily attached a pig’s kidney to a human body and watched it begin to work, a small step in the decades-long quest to one day use animal organs for life-saving transplants.

Pigs have been the most recent research focus to address the organ shortage, but among the hurdles: A sugar in pig cells, foreign to the human body, causes immediate organ rejection. The kidney for this experiment came from a gene-edited animal, engineered to eliminate that sugar and avoid an immune system attack.

Surgeons attached the pig kidney to a pair of large blood vessels outside the body of a deceased recipient so they could observe it for two days. The kidney did what it was supposed to do — filter waste and produce urine — and didn’t trigger rejection.

“It had absolutely normal function,” said Dr. Robert Montgomery, who led the surgical team last month at NYU Langone Health. “It didn’t have this immediate rejection that we have worried about.”

This research is “a significant step,” said Dr. Andrew Adams of the University of Minnesota Medical School, who was not part of the work. It will reassure patients, researchers and regulators “that we’re moving in the right direction.”

The dream of animal-to-human transplants — or xenotransplantation — goes back to the 17th century with stumbling attempts to use animal blood for transfusions. By the 20th century, surgeons were attempting transplants of organs from baboons into humans, notably Baby Fae, a dying infant, who lived 21 days with a baboon heart.