The heart failure patient who received a transplant from a gene-edited pig became infected with a porcine virus, Technology Review reports. It adds that this finding raises questions over whether the virus contributed to the patient's death, whether the donor pig was thoroughly tested for viruses, and whether the transplant should have occurred.
Surgeons at the University of Maryland performed the transplant earlier this year using a heart from a pig that had undergone gene editing to remove a sugar that causes many animal-to-human organ rejections, among other alterations. The patient, David Bennett, was ineligible to receive a human heart and received the gene-edited pig heart under a compassionate use emergency authorization from the US Food and Drug Administration. The Maryland team said that Bennett at first appeared to be recovering from his surgery before deteriorating and dying about two months after the transplant.
According to Tech Review, the team found that Bennett harbored porcine cytomegalovirus, even though the donor heart was not supposed to have it. In baboons, pig hearts with the virus triggered an inflammatory response leading to swelling, Tech Review notes, adding that experts tell it that that may have also occurred in this case. At the same time, it reports that though the donor pig was tested for porcine cytomegalovirus, one scientist tells it that the snout-based test they relied on may not have gotten a full picture of what was present in other tissues.
Accitionally, New York University bioethicist Arthur Caplan tells it that infection is "a big red flag" regarding the appropriateness of the procedure.
Tech Review adds that the transplant team says the procedure has led to "invaluable insights."