Surgeons have transplanted a lung from a genetically modified pig into a brain dead human recipient for the first time, with the organ functioning for nine days, researchers have revealed. The procedure, described in the journal Nature Medicine, marks the latest advance in xenotransplantation, a technique aimed at addressing the global organ shortage crisis. According to the World Health Organization, only up to 10% of the global need for organ transplants is currently being met.
The transplant was performed by a team in China, who used a lung from a Chinese Bama Xiang donor pig with six genetic modifications. The left lung was transplanted into a 39-year-old brain dead male recipient and remained viable and functional over a 216-hour period without triggering hyperacute rejection or signs of infection. However, 24 hours after transplantation, the lung showed signs of fluid accumulation and damage, possibly due to transplant-related inflammation. Despite immunosuppressive medication, the organ was progressively attacked by antibodies, leading to significant damage over time.
Experts have cautioned that there is still a long way to go before pig lungs can be used in living patients. Dr Justin Chan, a lung transplant surgeon at NYU Langone Transplant Institute not involved in the work, described the study as “exciting and promising” but noted it was a “qualified success” based on a single patient. “These lungs are not able to independently sustain a patient,” he said. Andrew Fisher, professor of respiratory transplant medicine at Newcastle University, agreed, stating: “This work is very welcome in furthering our understanding, but it marks an incremental step forward. There is much more work required and we are not on the dawn of an era of lung xenotransplantation using pig lungs.”
Xenotransplantation has become a hot area of research, with pig hearts, kidneys, and livers previously transplanted into humans. However, lungs pose particular challenges due to their constant exposure to the external environment, which requires a highly sensitive immune system. Professor Peter Friend from the University of Oxford noted that brain death itself causes an acute inflammatory state, complicating the results. The researchers said the approach needs refinement, including optimising immunosuppression, genetic modifications, and lung preservation. Other avenues, such as remodelling donor organs with stem cells or growing humanised organs in pigs, are also being explored.
