Serum bile acids in patients with acute liver failure supported with a bioartificial liver

BACKGROUND: Serum bile acids are increased in liver failure, but the composition of the bile acid pool in this condition has not been studied in detail. This information is of interest because of dihydroxy bile acid toxicity. METHODS: We measured serum bile acids by gas chromatography-mass spectrometry in 13 patients with fulminant liver failure and five patients with acute-on-chronic liver failure. Furthermore, serum bile acids were analysed in the same patients after 6 h of treatment with a bioartificial liver, consisting of a hollow-fibre cartridge with microcarrier-attached porcine hepatocytes and a charcoal column. RESULTS: Pre-bioartificial liver serum bile acids demonstrated a high dihydroxy/trihydroxy ratio and were higher in patients with acute-on-chronic liver failure than in those with fulminant liver failure (452.8 +/- 98.6 vs. 182.1 +/- 39.7 micro mol/L; P < 0.05). Bioartificial liver treatment decreased significantly serum bile acids in patients with fulminant liver failure (-38.8%) and acute-on-chronic liver failure (-35.8%), with a decreased dihydroxy/trihydroxy ratio. In vitro, porcine hepatocytes in the bioreactor cleared most conjugated bile acid species from pooled patient plasma. CONCLUSIONS: Acute liver failure is associated with very high serum levels of toxic bile acids that could contribute to the pathogenesis of the syndrome. Bioartificial liver treatment reduces both serum bile acid concentrations and the hydrophobicity of the bile acid pool.