GLYCINE CONJUGATION OF PARA-AMINOBENZOIC ACID (PABA) - A QUANTITATIVE TEST OF LIVER-FUNCTION

Objective: To evaluate glycine conjugation of para-aminobenzoic acid (PABA) to the hippurated metabolites, para-aminohippuric acid (PAHA), and para-acetamidohippuric acid (PAAHA) as a quantitative liver function test in patients with liver disease. Design and Methods: Serum concentrations of PABA and metabolites were measured by high pressure liquid chromatography in 24 controls and 50 patients with hepatobiliary disease. Results: Hippurate formation was significantly decreased in all patient groups with chronic liver disease versus controls. The hippurate ratio (% hippurated metabolites formed) correlated with severity of disease, serum albumin, and factor VII concentrations. PAHA concentration was a better prognostic indicator than factor VII concentrations in patients with acute liver disease; concentrations of zero correctly predicted a poor outcome in patients with fulminant liver failure. Conclusions: Glycine conjugation of PABA may be useful as a quantitative liver function test in patients with hepatobiliary disease and as a prognostic index in patients with fulminant liver failure.