Researchers detailed keeping lungs viable for 24 hours in a paper published in Science Advances, “Immune characterization of a xenogeneic human lung cross-circulation support system.“
Connection Between Living Pig and Donor Lungs
The researchers connected the circulatory system of a living pig and the donor’s lungs through a cross-circulation technique. The procedure is similar to some open-heart procedures in which the circulatory systems of the patient and the blood donor are linked to exchange oxygenated blood in a real-time transfusion.
Moreover, they demonstrated that their approach enhances the viability and functional recovery of human donor lungs. It may otherwise be rejected for transplantation in addition to working to extend the viability window.
Although the lungs were in good enough condition for a transplant, another issue cropped up. The pig-blood-preserved lungs were high in cellular infiltrates and deposits, and transplant recipients already exhibited a robust donor rejection response.
Neutralization of Pig Blood Immunoglobin
Researchers used cobra venom factor to neutralise the immunoglobulin that pig blood had accumulated in the lungs. Based on earlier studies, this cobra venom component protein has been shown to be a considerably more stable analogue of a protein present in the human immune system. Therefore, the cobra venom factor is perfect for this purpose because, unlike the human equivalent (complement C3), it remains stable for several hours. The presence of pig antibodies in donor tissue is still undesirable.
Donor lungs maintained the preservation of the overall architecture after 24 hours of xenogeneic cross-circulation. In addition, displayed improvements in the appearance and recruitment of consolidated segments. Furthermore, contrary to previous transplant preservation strategies, the lungs’ overall viability for transplant actually increased over time.
On the basis of this outstanding proof of concept, future research will seek to enhance it. Genetically immunodeficient pigs could be created to serve as transplant chaperones. It will prevent the antibody incursion problem is one potential direction the authors are interested in.
