Bioartificial liver support anno 2001

Despite maximal intensive care, mortality of acute fulminant hepatic failure is high: 60%-75% in several studies. In addition patients with chronic liver insufficiency suffer from a bad quality of life: all patients suffer from fatigue; symptoms of hepatic encephalopathy, jaundice, and itching are often present. Analogous to artificial kidney treatment in patients with renal failure, an artificial liver assist device is needed not only to bridge patients with fulminant hepatic failure to liver transplantation or own liver regeneration, but also to improve the quality of life of patients with chronic liver insufficiency. Several modalities of artificial liver support are under investigation, like plasma exchange, haemodialysis, haemadsorption, albumin dialysis, liver cell transplantation, and the bioartificial liver. Artificial livers based on only supportive detoxification function do not show significant improvement of survival in controlled studies. Bioartificial liver support systems have also the potential to support hepatic synthetic functions. Bioreactors can be charged with freshly isolated or cryopreserved porcine hepatocytes, but also by human hepatoma cell lines. Several uncontrolled studies in humans show safety of such a treatment, even by using porcine cells. Transmission of porcine endogenous retrovirus to recipients has not been found. Furthermore, beneficial effects have been reported on symptoms of hepatic encephalopathy, on the height of intracranial pressure and on hemodynamic parameters. By using porcine cells immunological problems (e.g., serum sickness) can be expected during treatments longer than one week. However, "proof of the pudding" in the sense of improvement of survival is not yet available. The creation of a "liver dialysis unit" in the near future depends mainly on the development of well-differentiated immortalized human hepatocytes. Some progress in this field has already been obtained.