For the first time, surgeons have successfully transplanted a genetically modified pig lung into a brain-dead human recipient, where it remained functional for nine days. The study, reported in Nature Medicine, represents a significant step in xenotransplantation—a technique aimed at addressing the global organ shortage, which currently meets only about 10% of demand, according to the World Health Organization.
Procedure and Findings
The transplant involved the left lung from a Chinese Bama Xiang pig with six genetic modifications, implanted into a 39-year-old brain-dead male. Researchers found the lung remained viable and functional over 216 hours, avoided hyperacute rejection, and showed no infection. However, fluid accumulation and antibody-mediated damage developed despite immunosuppressive treatment. Experts note that the patient’s remaining natural lung likely masked the full extent of the porcine lung’s deterioration.
Challenges of Lung Xenotransplantation
Lung transplantation from pigs is particularly complex. As Andrew Fisher from Newcastle University explained, lungs are constantly exposed to external pollutants and pathogens, making their immune system highly sensitive. This sensitivity increases the risk of organ rejection and complicates the development of viable xenotransplants. Peter Friend of Oxford University added that brain death itself induces an inflammatory state, further affecting outcomes.
Future Directions
The researchers emphasized that continued work is needed to optimize immunosuppressive regimens, refine genetic modifications, improve lung preservation, and assess long-term function. Xenotransplantation of other organs, such as kidneys, hearts, and livers, has already progressed, but lungs remain more challenging.
Alternative strategies are also under investigation, including:
- Remodeling human donor lungs previously deemed unsuitable
- Growing humanized organs in pigs or sheep
- Using stem cells to enhance donor organs
Experts believe that improving and repurposing human donor lungs could provide faster, practical solutions to the organ shortage, while xenotransplantation continues to advance as a promising but longer-term option.
