Strategies for liver support: from stem cells to xenotransplantation.

The continuing shortage of donor organs has been a major roadblock in orthotopic liver transplantation (OLT). This has led to the consideration of several potentially viable alternatives, including bioartificial and nonbiological liver assist devices, transplantation of mature hepatocytes or of stem/progenitor cells, and potential of transplanting xenogeneic organs and cells. Numerous investigators throughout the world are engaged in these investigations and the pace of discovery has begun to accelerate in recent years. To obtain an overview of progress in these areas, EASL sponsored a Monothematic Conference, which was held in Venice on 25th-26th September 2003. This conference was characterized by the enthusiastic participation of many leading investigators from various parts of the world. The present paper is a summary of the Monothematic Conference, including the related discussion and highlights some of the controversies in the areas of stem cells and transplantation. Since any such summary obviously cannot do full justice to the presentations and discussions at the conference, we apologize in advance for inadvertent omissions or lack of suitable emphasis on specific points. The conference was divided into several major sessions dealing with the biology of stem cells and nonparenchymal liver cells; basic aspects of hepatocyte transplantation; genetic and other manipulations of cells from the perspective of clinical applications; hepatocyte transplantation in people; and strategies for engineering bioartificial liver and nonbiological liver support devices. Moreover, several investigators presented ongoing research in relevant areas of stem cell biolog