Surgeons in China have successfully transplanted a genetically modified pig lung into a brain-dead human recipient, where it functioned for nine days. The study, published in Nature Medicine, represents a milestone in xenotransplantation—a field aiming to address the global shortage of donor organs. According to the World Health Organization, only about 10% of the demand for organ transplants is currently met.
The lung, from a Chinese Bama Xiang pig with six genetic modifications, was implanted into a 39-year-old brain-dead male. Researchers reported that the organ remained functional for 216 hours, avoided hyperacute rejection, and showed no signs of infection. However, fluid accumulation and antibody-mediated damage gradually impaired the lung, despite immunosuppressive therapy. Experts note that the recipient’s remaining natural lung may have masked the full extent of the damage.
Challenges of Lung Xenotransplantation
Lungs are particularly difficult for xenotransplantation because every breath exposes them to pollutants, pathogens, and environmental stress. “The immune system in the lung is very sensitive and very active, which poses extra challenges for transplantation,” said Andrew Fisher, professor of respiratory transplant medicine at Newcastle University. Brain death itself also triggers inflammation, complicating results, according to Oxford’s Peter Friend.
While xenotransplants of hearts, kidneys, and livers have progressed in recent years, lung transplantation remains especially complex. Only a few living patients have received pig organs, and survival beyond weeks or months has been limited.
Next Steps and Alternatives
The researchers emphasized the need to refine immunosuppressive regimens, improve genetic modifications, and develop better lung preservation strategies to extend graft function. Other promising avenues include reconditioning human donor lungs previously deemed unsuitable, growing humanized organs in pigs or sheep, and using stem cells to remodel donor organs.
Experts agree that while lung xenotransplantation holds promise, practical use in patients is still years away. If alternative strategies like reconditioning human lungs succeed, they could provide a faster solution to the organ shortage crisis.
