World’s First Pig Kidney Successfully Transplanted Into Human Without Organ Rejection
A pig kidney has been transplanted into a human for the first time without provoking rapid rejection by the recipient's immune system, a potentially significant breakthrough that may ultimately help ease a severe shortage of human organs for transplant.
The procedure was carried out at NYU Langone Health in New York City using a pig whose genes had been modified so that its tissues no longer contained a chemical known to cause almost immediate rejection.
According to Reuters, the receiver was a brain-dead patient with signs of renal dysfunction whose family authorized the experiment before she was scheduled to be taken off life support.
The transplanted kidney was attached to her blood arteries and kept outside her body for three days, allowing researchers access to it.
The transplanted kidney's function tests “looked pretty normal," according to transplant surgeon Dr. Robert Montgomery, who led the study.
According to him, the kidney produced “the amount of urine that you would expect" from a transplanted human kidney, and there was no indication of the aggressive, early rejection encountered when unmodified pig kidneys are transplanted into nonhuman primates.
Montgomery said that the recipient's elevated creatinine level – an indication of impaired kidney function – recovered to normal following the transplant.
According to the United Network for Organ Sharing, over 107,000 individuals in the United States are now waiting for organ transplants, with more than 90,000 awaiting a kidney.
The average wait duration for a kidney transplant is three to five years. Researchers have been working on the prospect of utilising animal organs for transplants for decades, but have been hindered by the question of how to avoid rapid rejection by the human body.
Montgomery's team hypothesised that removing the pig gene for a carbohydrate that causes rejection — a sugar molecule or glycan known as alpha-gal – would address the problems.
GalSafe is a genetically modified pig that was designed by United Therapeutics Corp's Revivicor unit.
The US Food and Drug Administration (FDA) authorised it in December 2020 for use as a food for individuals who are allergic to meat and as a possible source of human therapeutics.
The FDA said that medical products derived from the pigs would still need specific FDA approval before being administered in humans.
Other researchers are debating whether GalSafe pigs can be used to produce anything from heart valves to skin grafts for human patients.
source - healthline
According to Montgomery, a heart transplant recipient, the NYU kidney transplant experiment should pave the way for studies in patients with end-stage renal failure in the next year or two.
The strategy may be tested as a short-term solution for critically ill patients until a human kidney becomes obtainable, or as a permanent transplant in certain situations.
The present trial used a single transplant and the kidney was only kept in place for three days, so any future trials are likely to discover additional obstacles that will need to be addressed, according to Montgomery.
Patients with a low chance of obtaining a human kidney and a poor prognosis on dialysis would most likely be eligible.
“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 added.
Montgomery said that the researchers consulted with medical ethicists, legal professionals, and religious experts to evaluate the idea before asking a family for temporary access to a brain-dead patient.