Problems and challenges of genetically modified pig to non-human primate kidney xenotransplantation

Xenotransplantation is one of the potential approaches to mitigate the shortage of donor kidneys. With the progress of gene modification techniques and the development of immunosuppressant, significant progress has been made in the preclinical research of genetically modified pig to non-human primate (NHP) xenotransplantation. The longest survival time of recipients exceeds 500 d. However, the number of recipients surviving for over 1 year is extremely low, and most recipients die within postoperative 1-2 months. Therefore, several problems remain to be clarified and resolved. In this article, rejection, refractory coagulation dysfunction, persistent inflammation, the selection of immunosuppressant, the selection of clinical recipients and the risk of cross-infection in genetically modified pig to NHP xenotransplantation were reviewed, and current problems and potential solutions of genetically modified pig to NHP xenotransplantation were summarized, aiming to provide reference for promoting xenotransplantation in clinical settings.