First Pig-To-Human Heart Transplant May Have Failed Due To Pig Virus, Report Says

A Maryland man who died of no clear cause two months after receiving the first ever transplant of a genetically modified pig heart may have been the victim of a pig virus, according to MIT Technology Review.

David Bennett Jr., who had end-stage heart disease, received an interspecies transplant at Baltimore's University of Maryland Medical Center on January 7 and seemed to respond well before he died March 8.

According to MIT Technology Review, Bennett's transplant surgeon said at an American Society of Transplantation seminar last month that Bennett's death may have been caused by a heart disease.

The failure of pig-to-baboon organ transplants has been linked to the fact that the virus can cause respiratory symptoms in pigs.

Revivicor altered the pig's genome to reduce the risk of Bennett's body rejecting the heart and to prevent excess tissue growth after the transplant.

If the virus caused Bennett's death, it's an obstacle that can probably be overcome in future operations, according to a report.

Revivicor did not respond to a request for comment from Forbes, but they did not reply to a request for comment from MIT Technology Review.

The possibility that a pig virus could adapt to humans as a result of a transplant has worried researchers, who hope interspecies transplants could eventually help solve a dire shortage of human organ donors. A group of transplant researchers said in a paper published by the National Center for Biotechnology Information that animal transplant recipients and their personal contacts should be checked on at regular intervals because of the risk of dangerous cross-species disease transmission. Jay Fishman, a transplant infection specialist at Massachusetts General Hospital, told the MIT Technology Review that porcine cytomegalovirus is not thought to be able to cause disease in humans. Pig-to-human transplants have been used to test techniques, and have shown the danger posed by porcine cytomegaloviruses. A 2015 study published by the NCBI found pig-to-baboon heart transplants failed four times faster when the virus was present, while a 2020 study found pig-to-baboon heart transplants could last six months. The authors of the Nature study said that the high levels of the virus may have been caused by the intentional inhibition of the baboon's immune system during transplant or the absence of the pig's immune system. The researchers said that a human who received a pig heart would likely have a reduced survival time.

The man who received a pig heart in medical first died two months after the transplant.