Recently a phase I clinical trial has been started in Italy to bridge patients with acute liver failure (ALF) to orthotopic liver transplantation (OLT) by the AMC-bioartificial liver (AMC-BAL). The AMC-BAL is charged with 10 x 10(9) viable primary porcine hepatocytes isolated from a specified pathogen-free (SPF) pig. Here we report a patient with ALF due to acute HBV infection. This patient was treated for 35 h by two AMC-BAL treatments and was bridged to OLT. There was improvement of biochemical and clinical parameters during the treatment. No severe adverse events were observed during treatment and follow-up of 15 months after hospital discharge. Possible porcine endogenous retrovirus (PERV) activity could not be detected in the patient's blood or blood cells up to 12 months after treatment.