Artificial liver support: future aspects

Liver transplantation and blood purification therapy, including plasmapheresis, hemodiafiltration, and bioartificial liver support, are available to treat patients with severe liver failure. The two mainstream systems developed for bioartificial liver support are extracorporeal whole-liver perfusion (ECLP) and the bioreactor system (BIS). We developed a method of plasma cross-perfusion, in which plasma is exchanged between the blood circuit of the patient and that of a hepatic function unit, that is, whole liver or a bioreactor through which immunologically free whole human blood is perfused. From the aspects of efficacy and safety, the best system of bioartificial liver support for clinical use is considered to be ECLP in cross plasma perfusion. However, a social objection about zoonosis has consistently been raised, with controversy surrounding the use of xenogeneic organs for human treatment, and this might be a final obstacle to the development of system efficacy. The combination therapy of hemodiafiltration with the administration of human serum albumin and anticoagulant factors can minimize the economic and medical resource costs through the development of transgenic livestock that secrete human pharmaceuticals systemically. It is possible that this therapy will become the most practical treatment for patients with severe hepatic failure.