An update on hepatic stem cells: bench to bedside.

Liver failure results in impairment of many functions and dependent organs such as brain and kidneys begin to fail, reducing the chance of recovery even further. Orthotopic liver transplantation (OLTx) is the only treatment that improves the survival rate in patients with liver failure. Liver Transplantation (LT), including orthologous liver transplantation (OLT), cadaveric LT, split LT, living donor LT (LDLT) brings hopes to patients with these diseases. Globally, 1.4 million deaths occur annually as a result of chronic liver diseases. The reasons for this high death toll include unavailability of healthy liver donor and highly expensive liver transplantation treatment. Furthermore, some other factors such as operative risks and post-transplant rejection are major limitation of OLT. Isolated hepatocyte transplantation is emerging as alternative bridge support till the healthy donor is arranged. Mature hepatocytes have several drawbacks such as low proliferation both in vitro and in vivo, low viability after cryopreservation, and requirement of large number of cells for infusion. The studies on isolation of hepatic progenitors have shown promising results to overcome these limitations. These cells possess higher proliferative capacity, are less immunogenic and more resistant to cryopreservation, and ischemic injury; properties that could enhance their engraftment within the recipient liver. The hepatic progenitors have been isolated from the intra-hepatic sources and extra-hepatic sources. Fetal cells are one of the ideal sources of hepatic stem/progenitor cells. Autologous bone marrow stem cell transplantation in patients with cirrhosis has shown promising result.