Xeno-regenerative medicine: A novel concept for donor kidney fabrication.

Allogeneic kidney transplantation not only dramatically improves the prognosis and quality of life of patients with end-stage renal disease who require dialysis, but also provides significant medical economic benefits. However, due to chronic shortage of donor organs, patients have to continue to undergo dialysis, which can be stressful and expensive. To overcome such circumstances, xenotransplantation and kidney regeneration are being studied as the ultimate treatment options that can be a replacement for allogenic donor organs. A complete organ with vascular pedicles can be xenotransplanted; however, the control of immune response against a xenoantigen is one consideration. Conversely, regenerative medicine may be used to generate a self-organ or at least an allo-organ from iPS cells, but completion of a whole organ is another story. The creation of a hybrid organ that can compensate for the shortcomings of both xenotransplantation and regenerative medicine may be advocated. Here, we propose what we may call "xenogenerative medicine." The present review extracts the current limitations of each strategy, especially in Japan, and discusses how the combination of both the strategies may lead to dramatic progress in the development of a new organ creation method.