For the first time, a kidney from a pig has been transplanted into a human without triggering immediate rejection by the patient's immune system.
It's a potentially major medical advance that could eventually help alleviate a dire shortage of human organs for transplant.
The procedure done at NYU Langone Health in New York City involved the use of a pig whose genes had been altered
so that its tissues no longer contained a molecule known to trigger almost immediate rejection.
Researchers told Reuters the recipient was a brain-dead patient with signs of kidney dysfunction.
Her family consented to the experiment before she was due to be taken off of life support.
For three days, the new kidney was attached to her blood vessels and maintained outside her body, giving researchers access to it.
The significance of moving, you know, this into a human, I think, can't be understated.
Surgeon Dr. Robert Montgomery led the study.
All of the laboratory tests and everything that we did all looked pretty normal, you know, in terms of what we would expect when we did it in human transplant.
Montgomery said the patient's abnormal creatinine level -- an indicator of poor kidney function -- returned to normal after the transplant.
In the United States, nearly 107,000 people are presently waiting for organ transplants, including more than 90,000 awaiting a kidney, that's according to the United Network for Organ Sharing.
Wait times for a kidney average three-to-five years.
Montgomery said the NYU kidney transplant experiment should pave the way for trials in patients with end-stage kidney failure, possibly in the next year or two.