A genetically engineered pig heart which was transplanted into a baboon has survived more than a year without being rejected, leading scientists to hope that animal parts could one day provide a limitless sources of organs.
The hearts of genetically modified pigs could be transplanted into humans to solve the shortage of organ donors, scientists believe.
Researchers successfully grafted a pig heart into a baboon more than a year ago and it is still functioning, they report today.
Until now, organs transplanted into primates have only lasted for a maximum of six months before being rejected.
But scientists have tweaked the DNA of pigs so that their hearts are more compatible with primates and humans.
Through genetic changes, the scientists have added several human genes to the pig genome as well as removing genes which trigger a dangerous immune response in humans.
Grafts from these genetically engineered pigs are less likely to be seen as foreign, thus reducing the immune reaction against them.
“If successful, this method could change the current transplant paradigm, eliminating the shortage of donor organs including hearts, livers, kidneys, intestine, as well as insulin producing cells for treatment of diabetes.”
At present people needing a heart transplant must wait until a suitable donor heart becomes available. Last year 145 operations were carried out at seven hospitals in Britain.
However, only eight out of 10 people in the UK receive the transplant they needed because of a lack of suitable donors. Many adults and children are forced to wait more than a year for a new heart.
Those on waiting lists have to use an artificial heart but these are not perfect and have issues with power supplies, infection, and both clotting and haemolysis, the break down of red blood cells.
Transplantation using an animal organ, or xenotransplantation, has been proposed as an option to save human lives, but the challenge has been to stop hosts rejecting donor hearts.
The experiments involved using these genetically engineered pig hearts, transplanted in the abdomen of baboons alongside their actual hearts.
The next step is to use hearts from the same pigs to test their ability to provide full life support by replacing the original baboon heart.