Pig hearts could soon be tested in humans after scientists passed an important milestone by transplanting the organs into primates.
In 2000, the International Society for Heart and Lung Transplantation (ISHLT) suggested human trials would be considered once 60pc of primates could live for three months, with at least some indication that longer survival was possible.
Previous studies have only achieved up to 57 days survival, so the new research is the first to meet the criteria set out by the ISHLT, and represents a major step in the clinical use of pig hearts in humans.
Now surgeons in Germany, using pig hearts from animals that had been genetically modified to remove threatening viruses and prevent the body rejecting the foreign organ, have grafted pig hearts into five baboons and kept four of the animals alive for at least 90 days, with one still in good health for more than six months.
Writing in the journal ‘Nature’, cardiac surgeon Bruno Reichart, of Ludwig Maximilian University of Munich, said they had proved transplanting hearts worked in one of human’s closest relatives, and that 195-day survival was a ‘milestone’ in using the procedure in the clinic.
Professor Barry Fuller of University College London welcomed the development and said: “This is an impressive study on transplantation of organs between species.
“The possibility to use animal organs for transplantation to overcome organ shortages has been discussed for decades, but has never become a reality because the human body aggressively rejects animal organ transplants because of multiple and strong immune reactions.
“Scientists have developed genetically modified pigs which could in theory reduce this strong immune response, but even then, significant problems have remained.
“This new research can thus help both to bring organ xenotransplantation a step closer to human application.”
Although several medical procedures already use sterilised pig tissues, such as heart valves in cardiac surgery and corneal transplants, doctors believe the use of full organs could end a donor shortage.