WASHINGTON, July 13: Surgeons in the US have successfully transplanted genetically-engineered pig hearts into recently deceased humans, an advance towards a long-term goal of performing such surgeries regularly in living patients, researchers said.
The surgeries, known as xenotransplants, were performed on June 16 and July 6, at New York University (NYU) Langone’s Tisch Hospital.
Nader Moazami, surgical director of heart transplantation at the NYU Langone Transplant Institute, led the investigational procedures using hearts procured from a facility hundreds of miles away and transplanted into recently deceased donors maintained on ventilator support.
The transplant surgeries were performed over several hours and heart function was monitored for three days. The first heart xenotransplant concluded on June 19, 2022, and the second on July 9, 2022.
No signs of early rejection were observed in either organ and the hearts functioned normally with standard post-transplant medications and without additional mechanical support, the researchers said.
No presence of porcine cytomegalovirus (pCMV) was detected in either case. The operating room used for the study has been taken offline to be used only for future xenotransplantation research, they said.
The hearts were procured from pigs that had 10 genetic modifications, including 4 porcine gene “knockouts” to prevent rejection and abnormal organ growth as well as six human transgenes to promote expression of proteins that regulate important biologic pathways that can be disrupted by incompatibilities between pigs and humans.
No other investigational devices or medications were used in the study. The procurement, transport, transplant surgery, and immunosuppression were aligned with current clinical standards used in heart transplantation.
“Our goal is to integrate the practices used in a typical, everyday heart transplant, only with a nonhuman organ that will function normally without additional aid from untested devices or medicines,” Moazami said in statement.
“We seek to confirm that clinical trials can move ahead using this new supply of organs with the tried-and-true transplant practices we have perfected at the NYU Langone Transplant Institute,” Moazami said.
Alex Reyentovich, director of the NYU Langone Advanced Heart Failure program, said these latest advances in xenotransplantation move the field closer to realizing a new supply of organs for those facing life-threatening disease.
“These are the first steps in developing a deep understanding of the mechanical, molecular, and immunologic aspects of xenoheart transplantation and the feasibility of utilising standard clinical practice and tools to do so,” said Reyentovich.
Robert Montgomery, a professor at NYU Grossman School of Medicine, said xenotransplant studies with recently deceased donors are critical to gathering the additional human data needed to advance a field that for decades until last year had been tested only using nonhuman primates.
“The paradigm of whole-body donation — when organ donation is not a viable option — is critical to this work moving forward. We are so grateful to the families who volunteer to participate in this research, which will lead to saving untold thousands of more lives,” Montgomery said.
Montgomery, who led groundbreaking xenotransplant surgeries using single-gene knockout pig kidneys in September and November last year, said one of the critical elements of success to advancing this field is enhanced porcine virus monitoring, which was incorporated in these latest procedures.
“Other studies have shown that pCMV may be a factor in the success of xenotransplanted organs,” he said.
“More sensitive screening methods have been introduced to detect low-level traces of pCMV in the donor pigs. We have included that additional screening in this heart transplant protocol to give the organ the best chance at long-term survival,” Montgomary added. (PTI)
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