In January 2025, surgeons performed the fourth transplant of a kidney from what type of genetically modified animal?

In January 2025, a significant medical milestone occurred when surgeons performed the fourth transplant of a kidney from a genetically modified pig into a human recipient. This procedure represents a major advancement in the field of xenotransplantation, which involves transplanting organs or tissues between different species. The use of pigs as organ donors has become a focal point of research due to several compelling reasons, offering a potential solution to the critical shortage of human organs available for transplant.

Pigs are particularly well-suited for xenotransplantation because their organs, including kidneys, are remarkably similar in size and function to those of humans. Beyond anatomical compatibility, pigs also offer practical advantages for medical research and organ production. They have a relatively short gestation period and produce large litters, making it feasible to breed a sufficient supply of donor animals. Furthermore, pigs can be raised in controlled, pathogen-free environments, which significantly reduces the risk of transmitting diseases to human recipients, a concern that has historically complicated attempts with other animal species like non-human primates.

The success of these recent transplants hinges on advanced genetic engineering. Scientists use technologies such as CRISPR-Cas9 to modify pig genes, essentially "humanizing" the organs to prevent immediate rejection by the recipient's immune system. These genetic alterations typically involve removing pig genes that trigger a strong human immune response and adding human genes to improve compatibility and prevent complications like blood clotting. This innovative approach offers hope for a future where a more readily available supply of organs can save countless lives, addressing the severe global organ shortage.