Transplanting a pig’s kidney or heart into a human may seem like science fiction. In “It’s going much better”, on RTL, Dr Jimmy Mohamed, doctor and presenter, nevertheless recalls that xenografts are progressing, without having become standard treatment.
Can a xenograft address the lack of grafts?
A xenograft refers to the transplantation, in humans, of an organ or tissue from another animal species. The idea is coming back into the news because the need for transplants is increasing sharply. In its opinion no. 152, the National Consultative Ethics Committee indicates that those registered on the national waiting list increased from 15,538 on January 1, 2017 to 23,294 on January 1, 2026.
The CCNE therefore opens the way for research on xenografts in France, but in a demanding and complementary framework of human organ donation. It is not a question of replacing human transplants todaynor to make pig organs routinely available for all waiting patients.
In the column, Dr Jimmy Mohamed distinguishes two possible uses. The first is compassionate and experimental, for example in certain patients in therapeutic impasse with terminal heart failure, when a human transplant is not possible. The second mainly concerns the kidney: a xenograft could serve as a temporary bridgewhile waiting for a classic human transplant.
“It’s an open door, but one that we haven’t yet gone through.”
Why pork is studied, but not naturally compatible
The pig is of interest to research teams because some of its organs, notably the kidney, have similarities in size, anatomy and function with those of humans. This is one of the points put forward by Dr Jimmy Mohamed: according to him, the pig kidney is anatomically close to the human kidney.
But this proximity is not enough. The doctor explains that if we simply connected the blood vessels, the human immune system would reject the organ. Work on why pork is favored in xenografts is therefore based on a key step: the organs used come from genetically modified pigs.
These modifications seek in particular to limit immune rejection and certain infectious risks. They do not make the organ “compatible” in the simple sense of the term: they reduce major biological obstacles without removing them. This is why published cases remain followed as highly supervised medical experiments.
Another important nuance: the chronicle evokes hearts, kidneys and a liver. Available data confirm implantations of hearts and kidneys from genetically modified pigs in a few patients living in the United States, in experimental settings. For the liver, the American work concerns in particular an extracorporeal liver support device, and not a pig liver transplant implanted as routine care.
What the first cases show, without proving a general solution
The most telling case cited by Dr. Jimmy Mohamed concerns a 66-year-old American. A publication by Leonardo V. Riella and colleagues in The Lancet describes Tim Andrews, who lived
271 days without dialysis with a genetically modified pig kidneybefore then receiving a human kidney.
This result is spectacular on a patient scale: the pig kidney played a relay role. Dr Jimmy Mohamed also emphasizes that this patient could have avoided dialysis during this period, then benefited from a human transplant after the rejection of the pig kidney. True Medical also detailed how a patient lived 271 days without dialysis thanks to a pig kidney.
But this case alone does not demonstrate the effectiveness or safety of the method for all patients. This is a unique case, without a comparison group. The previous milestone mentioned in the column concerned an American woman who kept a pig kidney for a little over four months, a sign of rapid, but still limited, progress.
The questions to be resolved remain concrete:
- Evaluate the real benefit for very vulnerable patients;
- Guarantee informed consent to an experimental procedure;
- Monitor the risk of transmission or reactivation of animal infectious agents.
Research on a genetically modified pig kidney transplanted into a patient therefore shows a serious avenue, not a miracle solution.
Any transplant relies exclusively on specialized teams and a strict regulatory framework..