Allogeneic liver transplantation remains the only effective treatment available to patients with liver failure. Because of a serious shortage of liver donors, however, an alternative therapeutic approach is urgently needed. Transplantation of hepatocytes derived from adult or fetal livers is not a candidate for the alternative treatment because the source of such stem cells is limited to human liver at present. Recently, extrahepatic sources of hepatocyte lineage cells have been explored for use in cell therapy. Embryonic stem cells and Bone Marrow stem cells have been reported to have the potential to differentiate into multilineage cells, including hepatocytes, in in vitro and in vivo models. However, the clinical application of embryonic stem cells obtained from human fertilized eggs harbors serious problems in many countries. Also, the utilisation of human Bone Marrow cells as the graft source is restricted by a shortage of healthy donors. Our investigation demonstrates that Umbilical Cord Blood is a potentially suitable source of cell transplantation for liver injury. Umbilical Cord Blood will have relevance to the clinical application of cell transplantation as a novel therapeutic option for liver failure, as well as embryonic stem cells and adult-Bone Marrow-derived cells. Those Human umbilical cord blood cells have many advantages as grafts for cell transplantation because of the immaturity of newborn cells compared with adult cells. When we can successfully cryopre serve freshly isolated Umbilical Cord Blood cells, produce Umbilical Cord Blood -derived hepatic stem cells or hepatocytes on a large scale, and utilise them as a source of cell transplantation for decompensated liver diseases, we should be able to overcome the problems of ethics and short supply in allogeneic liver transplantation.



It was recently reported that Umbilical Cord Blood -derived stem cells had Bone Marrow -repopulating capacity. It is unclear whether Umbilical Cord Blood -derived cells function as mature hepatocytes for the support of liver injury though.