Clinical features and molecular mechanisms of acute liver failure

Both acute and chronic hepatic failure present diseases associated with high mortality. Acute liver failure (ALF) is a dramatic clinical syndrome in which a previously normal liver fails within days or weeks, resulting in haemorrhage, electrolyte and metabolic disturbance, cardiovascular instability, renal failure, cerebral oedema and encephalopathy. Worldwide the most frequent cause of acute liver failure is viral hepatitis. Advances in intensive care monitoring and the establishment of liver transplantation programmes have made a significant impact on survival of patients with ALF in the last 30 years. Depending on the time course three subgroups of ALF have been proposed: hyperacute, acute and subacute liver failure (O'Grady et al., 1993). Patients with hyperacute disease have the most favorable prognosis, while survival of patients with acute and subacute liver failure is still less than 15% (Plevris et al., 1998). Currently for the majority of the patients with acute and subacute liver failure orthotopic liver transplantation is the only curative therapy with long-term survival rates of approximately 90%. Organ availability, however, remains the most important limiting factor for liver transplantation. Although some patients may recover without liver transplantation, most of the patients die while waiting for a donor liver. Attempts have been made to remove toxins and to provide important liver products by the use of bioartificial supports systems. The objectives of these bioarteficial support system is to bridge patients to transplantation or recovery.