Surgeons at a New York City hospital have successfully attached a pig’s kidney to a person, whose immune system didn’t immediately reject the organ — a ground-breaking procedure that may one day lead to the use of animals in life-saving transplants.
The recipient at NYU Langone Health was a brain-dead woman who received the kidney of a pig whose genes had been altered so its tissues no longer harbored a molecule known to trigger almost immediate rejection, according to Reuters.
The family of the patient — who showed signs of kidney dysfunction — consented to the experiment before she was due to be removed from life support, scientists told the outlet.
Researchers had access to the kidney for three days as the organ was maintained outside her body while attached to her blood vessels, according to the news outlet.
Dr. Robert Montgomery, who led the study, said test results from the kidney’s function “looked pretty normal,” adding that the organ produced “the amount of urine that you would expect” from a transplanted human kidney.
The patient’s abnormal creatinine level — which indicates poor kidney function — returned to normal after the transplant, he said, and there was no sign of the strong, quick rejection seen when unmodified pig kidneys are transplanted into non-human primates.
In the US, almost 107,000 people are waiting for organ transplants, including more than 90,000 for kidneys, whose wait times average three to five years, according to the United Network for Organ Sharing.
For decades, researchers have been working on using animal organs for human transplants while preventing immediate rejection.
The genetically altered pigs — dubbed GalSafe — were developed by United Therapeutics’ Revivicor subsidiary. The animals lack a gene that produces alpha-gal, the sugar that provokes an immediate attack from the human immune system.
In December, the US Food and Drug Administration approved the gene alteration in the pigs as safe for human food consumption and medicine.
The FDA said medical products developed from the GalSafe pigs would still require specific approval from the agency before being used in humans.
“This is an important step forward in realizing the promise of xenotransplantation, which will save thousands of lives each year in the not-too-distant future,” United Therapeutics CEO Martine Rothblatt said in a statement.
The experiment at NYU should lead the way for trials in patients with end-stage kidney disease, possibly in the next year or two, said Montgomery, himself a heart transplant recipient.
Participants would probably be people with low odds of receiving a human kidney and a poor prognosis on dialysis.
“For a lot of those people, the mortality rate is as high as it is for some cancers, and we don’t think twice about using new drugs and doing new trials (in cancer patients) when it might give them a couple of months more of life,” Montgomery told Reuters.
Dr. Andrew Adams of the University of Minnesota Medical School, who was not part of the study, said the research is “a significant step” that will reassure patients, researchers and regulators “that we’re moving in the right direction.”
The dream of animal-to-human transplants dates back to the 17th century, when animal blood was used for transfusions.
By the 20th century, researchers were attempting transplants of organs from baboons into humans — notably Baby Fae, a dying infant who lived 21 days with a baboon heart.
Scientists then turned from primates to pigs, tinkering with their genes to bridge the species gap. The animals have advantages over primates because they are used for food, so tapping them for organs raises fewer ethical concerns.
Pigs also have large litters, short gestation periods and organs comparable to humans’.
In the NYU case, researchers kept the woman’s body going on a ventilator after her family agreed to the experiment. She had wished to donate her organs, but they weren’t suitable for traditional donation.
The family felt “there was a possibility that some good could come from this gift,” Montgomery said.
“I was one of those people lying in an ICU waiting and not knowing whether an organ was going to come in time,” said the doctor, who three years ago received a human heart from a donor with hepatitis C because he was willing to take any organ.
With Post wires