A cytomegalovirus would have infected the heart of the donor animal. Techniques used to avoid rejection would have masked this infection.
- A patient had benefited from the transplant of a genetically modified pig’s heart
- The cause of his death two months after the transplant was an infection of the transplanted organ.
It was a hope too quickly showered. The success of the first transplant of a pig’s heart on a human in January 2022 lasted only a few weeks: David Bennet, the patient who had benefited from it, died two months later. The cause of this failure would be, according to MIT Technology magazinecontamination of the transplanted organ by a cytomegalovirus, a virus endogenous to all pigs.
The transplanted heart infected with cytomegalovirus
“We are beginning to understand why he died,” the surgeon who performed the transplant, Bartley Griffith, of the University of Maryland School of Medicine, told the MIT journal. And to put forward the hypothesis of the transplanted porcine organ which would have been infected by a cytomegalovirus, a virus of which no transmission to humans has ever been recorded.
But how could this infection of the organ chosen for transplantation go unnoticed? This is because, in order to avoid the risk of rejection, the immune systems of organ transplant donors are intentionally inhibited so as not to contribute to the activation of the recipient’s body’s defense system. So the markers of a potential infection in the heart of the pig that was used for the transplant were not identifiable.
“A major surgical advance”
But despite the too rapid fatal outcome, this transplant has opened up new avenues. And in particular that which consisted in genetically modifying the donor animal to delete its own genes and integrate human genes, always with the aim of avoiding rejection of the transplanted organ. “It’s a major surgical breakthrough that brings us one step closer to solving the organ shortage.“, underlines Bartley Griffith in the MIT review.
