Isolation and immunohistochemical characterization of a pancreatic carcinoma-associated monoclonal antibody.

The aim of this study was to define a cellular antigen associated with human pancreatic ductal carcinoma, and to study its distribution in a large panel of malignant, benign, and normal tissues. For this purpose, monoclonal antibodies were generated against a postmicrosomal fraction of fresh human pancreatic cancer. One such antibody, LD-B1, reacted strongly with 95% of cases of primary and metastatic pancreatic ductal carcinomas. It also immunostained gallbladder carcinomas and cholangiocarcinomas. By contrast, it exhibited focal or weak reactivity to 10% of other types of common malignant tumors. On normal pancreas, staining was observed in ductal and centriacinar cells, but not in acinar or endocrine cells. In chronic pancreatitis, ductal staining intensity increased proportionally with the degree of cellular atypia. The antigen was also detected in gallbladder epithelium, bile ducts, ductal epithelium of sweat glands and salivary glands, and focally in a few other normal nonpancreatic tissues. These results suggest that LD-B1 MoAb can be used in immunohistochemical studies as a marker of pancreatic adenocarcinoma.