The first person to receive a pig kidney will have survived the transplant for two months. News which is not surprising – the man knew that his chances of survival were slim and the doctors knew he was in unknown territory – but which reminds us that the road is still long and uncertain.
In 2022 and 2023, it was the first two pig heart transplants that attracted attention — and the two people survived 60 and 40 days, respectively.
Doctors have long hoped that animal organ transplantation, or xenotransplantation, will be a lifeline for those desperately waiting for an organ donation. Experiments on primates have been carried out in the last decade, in particular by trying to take advantage of advances in genetic manipulation – the idea being to identify the combination of genes which would avoid rejection by our immune system. The results of these experiments were sometimes encouraging: but the brief survival of the first three patients showed the most enthusiastic that the transition from primate to human was not assured.
And we’ve been talking about it for even longer, if we remember that in December 1994, at the Royal Victoria Hospital in Montreal, doctors temporarily connected a 55-year-old patient to a pig’s liver – just long enough for us to transplant the human liver she was waiting for, a few hours later.
The pig is targeted, among other things, because the size and anatomy of its organs resemble ours.
Doctors specializing in xenotransplantation, interviewed by Nature last week, preferred to see the lessons learned from these three deaths than the length of the road ahead: lessons that range from the number of tests the “donor” organ must undergo to the types of drugs humans must receive to limit the risks of rejection or infections. “I’m encouraged that we’ve come this far,” says surgeon Robert Montgomery of New York University. He is one of the 55 co-authors of a study published on May 17 in Nature Medicine and recounting the two heart transplants.
A fourth xenotransplantation took place on April 12, on a 54-year-old patient, Lisa Pisano, this time a kidney. In an interview with the media on April 24, she said she felt good. The last we heard in mid-May, she was still under observation in hospital.
As uncertain as the results are, these four transplants received authorization from the US agency (the FDA) responsible for approving medical treatments, under what is called “compassionate access” — an authorization to Emergency granted exceptionally when a person’s life is at risk and no other treatment is available. Since 2022, researchers have been calling for the FDA to go further and start real clinical trials.
