Elevated serum levels of a biliary glycoprotein (BGP I) in patients with liver or biliary tract disease.

Human hepatic bile contains a glycoprotein (biliary glycoprotein I, BGP I) which cross-reacts with the carcinoembryonic antigen (CEA). A radioimmunoassay for BGP I was developed. The interference of CEA or 'non-specific cross-reacting antigen' (NCA) in the assay was small. The serum levels of BGP I were determined in healthy subjects, in patients with hepato-biliary diseases and in patients with various infectious or inflammatory disorders. Healthy individuals, including pregnant women, had a serum BGP I concentration of about 0.5-1 mg/l. Diseases of the liver or biliary tract (e.g. hepatitis A or B, cytomegalovirus hepatitis, obstructive jaundice or primary biliary cirrhosis) were associated with elevated serum levels of BGP I, as opposed to infectious diseases not affecting the liver mostly showing values within the normal range. Raised levels of serum BGP I activity may reflect biliary obstruction as a result of interference with normal BGP I secretion to the bile.