David Bennett Sr – the world’s first recipient of genetically modified pig heart – may have died of ‘a porcine virus’ present in the pig’s heart, Massachusetts Institute of Technology has said in its latest report quoting transplant specialists.
The American was nearing death in January. In a last-ditch effort to save his life, Bennett received a genetically edited pig heart in a landmark xenotransplantation operation. However, the 57-year-old died 40 days after the surgery, raising doubts about the experiment.
In a statement released in March, those involved in the procedure said there was “no obvious cause identified at the time of his death” and that a full report was pending. “Following surgery, the transplanted heart performed very well for several weeks without any signs of rejection. His condition began deteriorating several days after the operation,” The University of Maryland Medical Centre (where the operation was carried out) reportedly stated.
Virus present in pig’s heart believed to be cause of death
In its latest report on the matter, the MIT highlighted that the heart received by Bennett was affected by porcine cytomegalovirus, a preventable infection that is linked to devastating effects on transplants. “We are beginning to learn why he passed on,” transplant surgeon Bartley Griffith said. “Maybe, the virus was the actor, or could be the actor, that set this whole thing off, ” he was quoted as saying.
Would Bennett have lived if the virus was not present in the pig’s heart?
Experts are of the view that if a pig virus played a role in Bennett’s death, it could mean a virus-free heart could last much longer. Some surgeons think that with the latest gene-modification technology and rigorous procedures, they should be able to screen out the virus. “If this was an infection, we can likely prevent it in the future,” surgeon Griffith said.
What does ‘genetically modified’ heart mean?
The human immunity system works in such a way that it ferociously attacks foreign cells in a process called rejection. In xenotransplantation – cross species organ transplants – the body is bound to attack the animal organ since it treats it as a foreign substance. To avoid rejection, companies have been engineering pigs by removing some genes and adding others to give their tissue a stealth profile that hides from immune attack.
Another pandemic from pig virus?
Some experts fear that transferring pig viruses to humans could set off another pandemic if a virus were to adapt inside a patient’s body and then spread to doctors and nurses. “The concern could be serious enough to require lifelong monitoring for patients,” experts told MIT.
However, the specific type of virus found in Bennett’s donor heart “is not believed capable of infecting human cells,” Jay Fishman, a specialist in transplant infections at Massachusetts General Hospital was quoted as saying. Fishman thinks there is “no real risk to humans” of its spreading further.