The first transplant patient with a genetically modified pig heart died
The man had terminal heart disease and was not deemed suitable for a conventional heart transplant. Although the surgery had a positive outcome and no signs of rejection, Bennett's condition began to deteriorate rapidly after two months, even if the hospital did not report a specific cause of death. Despite this, the patient's choice to undergo the operation and his convalescence, albeit relatively short, have offered new knowledge for the future benefit of people in need of an organ transplant, whose demand is constantly higher than the supply.
For the first time a genetically modified pig heart was transplanted into a human being The patient, who had no other possibility of treatment, survived the xenotransplantation and for the moment there is no rejection. This success could be the first step on the road to mitigating the problem of organ shortage Read the article The first genetically modified xenograft David Bennett, 57 years old and with terminal heart disease, arrived for the first time in the Baltimore university facility in October 2021, where he was bedridden and subjected to extracorporeal circulation to stay alive. Due to his extremely complex clinical conditions, neither the hospital where he was admitted nor other health facilities considered him suitable for a conventional heart transplant.
So on December 31, 2021 the Food and Drug Administration (Fda), the US regulatory agency, granted the compassionate use emergency authorization for a xenograft surgery, that is, a transplant of an organ resulting from an animal, in this case a pig heart, genetically modified in order to minimize the dangerous mechanisms of rejection (which represent the main cause of failure of interventions of this type). It was the first time that a similar transplant had been experimented (here we talked about the first genetically modified pig kidney xenograft, performed on a person kept alive artificially).
Studies on xenografts In reality the Xenografts have been studied for a long time, as they would significantly expand the number of organs available to people in need of an organ transplant, which are constantly increasing. Yet they involve numerous risks linked above all to the immune response of the recipient, which manifests itself with the phenomena of rejection. Thanks to the advances made by science in the biotechnological field, in recent years research on xenotransplants is experiencing renewed interest, since, thanks to the genetic modifications performed on animals, it would be possible to minimize the immune response of the recipient and the phenomena of rejection, increasing the life expectancy of transplant patients.
The pig heart chosen for Bennett's surgery was produced by the US regenerative medicine company Revivicor, which used pigs with ten different genetic modifications. In particular, three genes responsible for rejection mediated by human antibodies against porcine tissues had been eliminated, a gene to prevent the overgrowth of the tissue of the new transplanted heart and six human genes capable of making the new organ "accept" by of the recipient's immune system.
The last hope For Bennett, therefore, xenograft represented the last hope for survival. Before agreeing to receive the transplant, the man was fully aware of the risks of the procedure, the first ever of its kind, with unknown risks and benefits. “Either die or have this transplant. I know it's a leap of faith, but it's my only choice, "said Bennett the day before the surgery, which ultimately proved to be a success.
After the operation, in fact, the transplanted heart had functioned very well for several weeks without any signs of rejection, representing the first experimental evidence that a genetically modified animal heart can function like a human heart, without immediate rejection by the organism that received it.
As the hospital reports, in the weeks following the surgery Bennett was able to spend time with his family and start physiotherapy to get back on his feet. Then, however, his conditions worsened until he precipitated two months after the transplant. Bartley P. Griffith, the physician who performed the operation, says in a press release that all of the hospital's medical staff are "devastated" by the loss of Bennett, who "has become famous among millions around the world for his courage and his firm will to live ". Despite this epilogue, Bennett's choice to undergo the experimental operation not only allowed him to live a few more months, but also to offer hope for the future to people in need of an organ transplant.
"We have gained invaluable insights, learning that genetically modified pig heart can function well within the human body while the immune system is adequately suppressed - said Muhammad M. Mohiuddin, scientific director of the xenotransplantation program Baltimore Hospital - We remain optimistic and plan to continue our work in future clinical trials. "
Griffith went on to add: "As with any first transplant surgery in the world, this has led to valuable information that will hopefully inform transplant surgeons to improve outcomes and potentially provide life-saving benefits to future patients." . The same hopes are shared by Bennett's family. David Bennett, Jr., son of the patient, said: “We hope this story can be the beginning and not the end, that what has been learned from the surgery will benefit future patients and hopefully a day to end the organ shortage, which costs so many lives every year ".
