Heart transplant

First pig-to-human heart transplant may have failed due to pig virus, report says


A Maryland man who died with no clear cause two months after receiving the first-ever genetically-modified pig heart transplant may have fallen victim to a pig virus linked to transplant failure, the patient’s doctor has found, according to MIT Technology Review.


David Bennett Sr., who had terminal heart disease, received the interspecies transplant on Jan. 7 at the University of Maryland Medical Center in Baltimore, and he initially appeared to respond well before deteriorating from unexpected way and to die on March 8.

Dr. Bartley Griffith, Bennett’s transplant surgeon, told an American Society of Transplantation webinar last month that the heart was infected with porcine cytomegalovirus, which may have caused Bennett’s death, MIT Technology Review reported Wednesday.

The virus, which can cause respiratory symptoms and pregnancy complications in pigs, has been linked to failed pig-to-baboon organ transplants.

The pig was bred by biotech company Revivicor, which modified the pig’s genome to reduce the risk of Bennett’s body rejecting the heart and to prevent excessive tissue growth after the transplant.

If the virus caused Bennett’s death, it represents an obstacle that can likely be overcome in future operations, Griffith reportedly said during the webinar.

Revivicor declined to comment on the virus for MIT Technology Review, and did not immediately respond to a request for comment from Forbes.

Key Context

The possibility that a pig virus could adapt to infect humans following a transplant has worried researchers, who hope that cross-species transplants could eventually help solve a serious shortage of human organ donors. Because of the risk of dangerous disease transmission between species, recipients of animal transplants and their personal contacts – including pets – should be checked at regular intervals, a group of transplant researchers said in a paper by 2013 published by the National Center for Biotechnology Information. However, porcine cytomegalovirus is thought not to be able to infect humans, said Massachusetts General Hospital transplant infection specialist Jay Fishman. MIT Technology Review. Baboons have been used to test pig-to-human transplantation techniques and have shown the danger posed by porcine cytomegalovirus. A 2015 study published by the NCBI found that pig-to-baboon kidney transplants failed nearly four times faster when the virus was present, and a 2020 Nature One study found that pig-to-baboon heart transplants with the virus failed quickly while transplants without the virus could last over six months. The authors of the Nature According to one study, infected hearts had extremely high levels of virus, possibly due to intentional suppression of the baboon’s immune system during transplantation or due to the absence of the pig’s immune system, which could have be better suited to suppress a pig-specific virus. A human who received a heart infected with porcine cytomegalovirus would most likely suffer from the same reduced survival time, the researchers said.

Further reading

“Man Who Received Medicine Pig’s Heart Dies For First Time 2 Months After Transplant” (Forbes)