Doctor tells of virus in pig heart of transplant patient who died 2 months later
The death of a man, who received a pig heart in place of his own, may have been hastened by another thing he got from the pig: a common virus.
In David Bennett Snr’s weakened state, the virus called pig cytomegalovirus might have been one of several factors that contributed to his eventual demise, according to Dr Muhammad Mohiuddin, who co-led the University of Maryland Medicine team that performed the January 7 transplant.
Bennett died two months after receiving the pig heart, which itself was a last-ditch effort to save his life.
An autopsy after Bennett’s death suggested that while the pig heart had been pumping well, scar tissue was building up in the organ, thickening it and preventing it from fully relaxing after pushing through the blood.
Examination also revealed the presence of pig cytomegalovirus, the porcine version of a very common human virus usually kept in check by the immune system.
A polymerase chain reaction analysis of tissue from Bennett’s heart showed some viral DNA, though researchers found no clear signs of infection.
The pig cytomegalovirus clearly came from the transplant and was not something Bennett caught earlier, Mohiuddin said, although the pig had been checked for the virus using all available testing methods.
No scientific evidence suggested a pig cytomegalovirus infection could cause the thickening seen in Bennett’s heart, the doctor said, but it could not entirely be ruled out either. Information about the presence of pig cytomegalovirus was first reported by Technology Review, based on a presentation a colleague of Mohiuddin gave at a scientific conference.
It was one of three or four factors that could have contributed to Bennett’s death, Mohiuddin said, pointing particularly to the Bennett’s weakened state before, during and after the transplant surgery.
“All these things were going on and all contributed to his up and down condition,” said Mohiuddin, whose team plans to publish its findings in a scientific journal. “Whether all of them contributed a little bit [to his death] or one contributed more than another, that’s the difficult part.”
Before Bennett’s experience, it was not clear whether the human body would immediately reject a pig heart, even one from a pig that had been gene-edited to reduce rejection risks.
Understanding precisely what led to Bennett’s death would help the field avoid similar situations in future, he said.