First successful transplant of the heart of a genetically modified pig to a human. This is David Bennett Sr, 57, a Maryland resident. The operation, writes the New York Times, lasted eight hours and was performed in Baltimore. The new organ “creates the beat, creates the pressure, is his heart,” said Dr. Bartley Griffith, director of the medical center’s transplant program, author of the intervention. “It works and looks normal but we don’t know what will happen tomorrow, it has never been done before,” he added.
The man in question had a life-threatening heart disease. The potential breakthrough could someday lead to the provision of animal organs for transplantation into patients. About 41,354 Americans received an organ transplant last year, a kidney for more than half of them, according to the United Network for Organ Sharing, a nonprofit that coordinates national efforts to procure organs. But there is a great shortage, so much so that about a dozen people on the list die every day. Scientists have been working feverishly to develop pigs whose organs are not rejected by the human body, and research has accelerated over the past decade thanks to new gene editing and cloning technologies.
Transplants: from a chimpanzee kidney, 60 years of trying
Xenotransplantation, the transplantation of organs from animals to humans, is a challenge that began almost sixty years ago. In the seventeenth century there were the first attempts to use animal blood for transfusions but only in 1963 the American doctor Keith Reemtsma implanted the kidney of a chimpanzee in a 44-year-old man. However, the operation was not successful and even in the following ones, also made using the liver and heart taken from baboons or chimpanzees, the luckiest patient lived 9 months. In 1984, a group of surgeons from Loma Linda University in California attempted to transplant a baboon heart into a baby girl, remembered as Baby Fae. Stephanie Fae Beauclair, this is her name, was an American girl born with hypoplastic left heart syndrome: the transplant was a success even if she died after three weeks of a rejection crisis and kidney and heart complications.
Last October, surgeons in New York had transplanted the kidney of a genetically engineered pig into a brain dead person. Currently, as demonstrated by the Baltimore heart transplant, it is believed that the pig is the most suitable animal for transplanting organs to humans, as it is better compatible from an anatomical and physiological point of view. Pigs reduce the risk of virus transmission because pigs can be created free of almost all agents potentially dangerous to humans, with the sole exception of porcine retroviruses. Pigs offer the advantage of being easy to rear and the organs, which can be transplanted from the patient’s pluripotent stem cells, reach the size suitable for transplantation into a human body in just six months. Since the transplanted organ is autologous – that is, made up of the patient’s cells – the patient should not take potentially harmful immunosuppressive drugs.