Current status and future perspectives of xenotransplantation and stem cell research in transplantation field

The severe shortage of human organ donors is one of the biggest problems with organ transplantation. The solution for this problem would be development of artificial organs or mechanical devices, stem cell derived organs, and xenogeneic organs. Artificial organs may provide a short term life or functional support, but they cannot be considered as a life -long curative therapeutic modality in the near future. Although considerable efforts have been invested in the production of lab-grown organs using stem cells, clinical application of these organs will demand many years of research and investment. Currently. stem cells are clinically applied in cell replacement therapy. Therefore, xenotransplantation would be the most imminent solution for the organ shortage. Recent advances in our understanding of the mechanisms of xenograft rejection, zoonotic infections including PERV (porcine endogenous retrovirus). and production of alpha-1.3-galactosyltransferase deficient pigs, put xenotransplantation closer to the clinical reality. At this stage, pancreatic islet xenotransplantation would be the first target for clinical application, the efficacy of which has been proven in non human primate study and is waiting for the development of relatively non-toxic or clinically applicable immunosuppressive or tolerance- inducing regimens.