A team of US researchers successfully transplanted two genetically engineered pig hearts into recently deceased humans in June and July.
The surgeries, known as xenotransplants, were performed on June 16 and July 6 at NYU Langone's Tisch Hospital. These marked the latest advances toward addressing the organ shortage and developing a clinical protocol that would provide an alternative supply of organs for people with life-threatening heart disease.
The transplant surgeries were performed over several hours and heart function was monitored for three days.
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.
Using a new infectious disease protocol, no presence of porcine cytomegalovirus (pCMV) was detected in either case, the team said.
"Our goal is to integrate the practices used in a typical, everyday heart transplant, only with a non-human organ that will function normally without additional aid from untested devices or medicines," said Nader Moazami, surgical director of heart transplantation at the NYU Langone.
"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 added.
Strict protocols to prevent and monitor potential zoonotic transmission of porcine endogenous retrovirus (PERV) were also carried out.
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 6 human transgenes ("knock-ins") 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 this NYU Langone Health study.
Meanwhile, the US Food and Drug Administration (FDA) is also considering approving human clinical trials for pig-to-human organ transplants.
According to Alex Reyentovich, medical director of heart transplantation at NYU Langone, these latest advances in xenotransplantation move the field closer to realising 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," Reyentovich said.
(With inputs from IANS)
