Surgeons in China have successfully transplanted a genetically modified pig lung into a brain-dead human recipient, with the organ functioning for nine days. The procedure, published in Nature Medicine, represents a significant advance in xenotransplantation, a field aimed at addressing the global organ shortage. According to the World Health Organization, only about 10% of worldwide transplant demand is currently met.
The lung came from a Chinese Bama Xiang pig with six genetic modifications designed to reduce rejection by the human immune system. The recipient, a 39-year-old male, retained his own remaining lung, which helped compensate for any damage to the transplanted organ. Researchers reported that the lung avoided hyperacute rejection and infection during the 216-hour period, though fluid accumulation and antibody-mediated damage occurred despite strong immunosuppressive therapy.
Challenges of Lung Xenotransplantation
Experts stress that while promising, the experiment is a cautious step forward. Lungs are particularly difficult to transplant because they constantly interact with the environment, exposing them to pathogens, pollution, and other stressors. “The immune system in the lung is very sensitive and very active,” said Andrew Fisher, professor of respiratory transplant medicine at Newcastle University, emphasizing that more work is needed before pig lungs can be used in living patients.
Brain death itself also complicates outcomes, noted Prof. Peter Friend of Oxford University, as it triggers an acute inflammatory state that can affect transplanted organs.
Future Directions
Researchers highlight the need to refine genetic modifications, improve immunosuppressive regimens, and enhance lung preservation strategies to achieve long-term function. Other approaches to increasing organ availability are also being explored, including remodeling donor lungs using stem cells and growing humanized organs inside pigs or sheep.
Fisher noted that improving the usability of human donor lungs deemed unsuitable for transplantation could provide a faster, more immediate solution to the organ shortage. While lung xenotransplantation holds potential, experts agree that its widespread clinical application remains a goal for the future rather than an imminent reality.
