Carcinoembryonic antigen in normal and diseased liver tissue

Many reports have demonstrated an elevation of circulating carcinoembryonic antigen (CEA) in the majority of patients with alcoholic liver disease and, less frequently, in patients with nonalcoholic liver disease. Several explanations for this finding have been proposed, eg, increased production or release of CEA by the damaged liver, decreased hepatic metabolism, or diminished excretion of CEA of extrahepatic origin. In an attempt to clarify the mechanism of CEA elevation in liver disease, we have compared the CEA plasma level as measured by radioimmunoassay with CEA demonstrable in liver tissue by the indirect fluorescent antibody technique in 7 patients without significant changes in the liver biopsy specimen, 23 patients with alcoholic liver disease, and 16 patients with miscellaneous liver diseases such as acute or chronic nonalcoholic hepatitis or extrahepatic biliary obstruction. The mean CEA plasma level in patients with alcoholic liver disease was significantly higher than in patients with nonalcoholic liver disease (8.8 +/- 9.5 vs 2.7 +/- 2.5 ng/ml; P less than 0.02). In normal liver tissue, CEA was observed in the apical cytoplasm and along the luminal surface of bile duct epithelial cells, suggesting that under normal conditions CEA accumulates in and is excreted by bile ducts. In patients with alcoholic hepatitis and/or cirrhosis there was marked bile ductular proliferation and prominent cytoplasmic CEA-specific staining and both were associated with elevated CEA plasma levels in more than 80% of cases. In the group of miscellaneous liver diseases, bile ductule counts and CEA-specific staining did not correlate with CEA plasma levels. These observations suggest that proliferating bile ductules contribute to elevated plasma CEA in alcoholic patients.