Detection of an oncofetal antigen (DU‐PAN‐2) in sera of patients with non‐malignant hepatobiliary diseases and hepatomas

DU‐PAN‐2 is a high‐molecular‐weight glycoprotein defined by a murine monoclonal antibody (MAb) elicited against a human pancreatic adenocarcinoma cell line. This MAb recogonizes an oncofetal antigen present on the surface of normal pancreatic and bile‐duct epithelium, normal bronchus epithelium, and some adenocarcinomas. Elevated levels of the antigen (> 400 U/ml) have been detected in the serum of 79% of patients with adenocarcinoma of the pancreas and in a small percentage of patients with other adenocarcinomas, by means of a competition radioimmunoassay. Here, we have studied DU‐PAN‐2 antigen levels in sera of patients with a spectrum of hepatobiliary diseases and controls. Serum DU‐PAN‐2 antigen was elevated in 59% of 112 patients with non‐malignant hepatobiliary diseases and in 50% of hepatoma patients. None of 50 healthy controls had elevated serum DU‐PAN‐2 levels. Patients in every category of hepatobiliary disease studied had elevated median serum DU‐PAN‐2 levels; the highest median levels were seen in patients with primary biliary cirrhosis (1,296 U/ml) and the lowest in stable cirrhosis (300 U/ml). Elevated serum DU‐PAN‐2 levels in one patient with primary biliary cirrhosis and in one patient with hepatoma returned to normal following liver transplantation. Serum DU‐PAN‐2 levels did not correlate well with alkaline phosphatase, 5′‐nucleotidase, bilirubin, or α‐fetoprotein. Using an immunoperoxidase technique on formalin‐fixed, deparaffinized liver sections, we showed that DU‐PAN‐2 MAb reacted heterogeneously with bile‐duct epithelium but never stained hepatocytes or hepatoma cells. While serum DU‐PAN‐2 levels may be useful in detecting and monitoring pancreatic adenocarcinoma, they are not specific for this disease.