Gene editing spurs hope for organ transplants from animals
In a striking advance that helps open the door to organ transplants from animals, researchers have created geneedited piglets cleansed of viruses that might cause disease in humans.
The experiments, reported on Thursday in the journal Science, may make it possible one day to transplant livers, hearts and other organs from pigs into humans, a hope that experts had all but given up.
If pig organs were shown to be safe and effective, “they could be a real game changer,” said David Klassen, chief medical officer at the United Network for Organ Sharing, a private, nonprofit organisation that manages the nation’s transplant system. There were 33,600 organ transplants last year, and 116,800 patients on waiting lists, according to Klassen, who was not involved in the new study. “There’s a big gap between organ supply and organ demand,” he said. George Church, a geneticist at Harvard who led the experiments, said the first pig-tohuman transplants could occur within two years. The new research combines two great achievements in recent years — gene editing and cloning — and is unfolding quickly. But the work is novel and its course unpredictable, Klassen noted.
It may be years before enough is known about the safety of pig organ transplants to allow them to be used widely. The idea of using pigs as organ factories has tantalised investigators for decades. Porcine organs can be the right size for human transplantation, and in theory, similar enough to function in patients.
But the prospect also raises thorny questions about animal exploitation and welfare. Already an estimated 100 million pigs are killed in the United States each year for food. Scientists pursuing this goal argue that the few thousand pigs grown for their organs would represent just a small fraction of that total, and that they would be used to save human lives. The animals would be anesthetised and killed humanely.
Major religious groups have already weighed in, generally concluding that pig organs are acceptable for lifesaving transplants, noted Jay Fishman, codirector of the transplant program at Massachusetts General Hospital. Pig heart valves already are routinely transplanted into patients.
(Some leaders in the Jewish and Muslim communities, though, do not endorse pig kidneys for transplant, reasoning that patients with kidney failure can survive with dialysis.)