Surgeons have, for the first time, transplanted a lung from a genetically modified pig into a brain-dead human and found that the organ functioned for nine days, researchers reported.

The procedure is part of research in the field of xenotransplantation—a technique aimed at addressing the organ shortage crisis. According to the World Health Organization, only about 10% of the global need for such transplants is being met, The Guardian reported.

Experts, however, emphasize that there is still a long way to go before pig lungs can be used in patients. Dr. Justin Chan, a lung transplant surgeon at the NYU Langone Transplant Institute who was not involved in the study, called the work “exciting and promising,” but noted that it concerns only a single patient and the result is a “conditional success.” “These lungs cannot independently sustain a patient,” he added.

Prof. Andrew Fisher from Newcastle University also noted that the study is “a small step forward” and that we are far from the era of xenotransplantation with pig lungs.

In recent years, xenotransplantation has been actively developing, with pig hearts, kidneys, and livers already transplanted into humans. The organs are usually genetically modified by removing certain pig genes and introducing human genes to reduce rejection by the recipient’s body.

Research often begins with brain-dead patients before, in some cases, being applied to living humans. Although the number of living recipients is limited, some have survived with functioning organs for months after the procedure.

However, specialists point out that lung transplants are particularly challenging. “Every breath introduces the external environment into the body,” Fisher explained. “Lungs have to respond to pollution, infections, and other assaults, making them extremely sensitive—a challenge for transplantation.”

In an article in Nature Medicine, Chinese researchers described the transplantation of the left lung from a Bama Xiang donor pig with six genetic modifications into a 39-year-old brain-dead man. The organ remained viable and functional for 216 hours, without triggering a hyperactive rejection response or infections.

Nevertheless, 24 hours after surgery, the lung showed signs of fluid accumulation and damage, likely due to inflammation related to the transplant. Despite strong immunosuppressants, the organ was gradually attacked by antibodies, resulting in significant damage over time.

Prof. Peter Friend from the University of Oxford noted that brain death itself induces an acute inflammatory state, which may affect the observed outcomes.

Researchers call for improvements in immunosuppressive regimens, genetic modifications, lung preservation strategies, and assessment of long-term graft function.

Fisher added that another promising approach is to “rescue” human donor lungs considered unusable for transplantation. “If we achieve this, it could be applied within months and provide significant benefits in the coming years,” he said. | BGNES