Monoclonal antibody localization of Lewis antigens in fixed tissue

Monoclonal antibodies that bind specifically with Lewisa (Lea) and Lewisb (Leb) antigens were used in an immunoperoxidase assay to characterize Lewis (Le) antigenic profile of a variety of fixed tissues. Representative sections of normal and malignant tissue from the stomach, colon, pancreas, and kidney were examined and compared. Lea antigen was expressed more often in gastric adenocarcinomas (80%) than normal gastric mucosa (40%). In gastric tumors with concomitant expression of Le antigens, larger areas within an individual tumor expressed Lea antigen rather than Leb antigen. Expression of Leb antigen in normal colonic tissue was seen only in the proximal colon and not distal colon; colon carcinomas, on the other hand, expressed Leb antigen (64%) regardless of where the primary arose. Leb antigen was expressed in large pancreatic ducts (three of three) more often than Lea antigen (one of three); exclusive expression of Lea antigen was demonstrated in the proximal convoluted tubules of normal kidney (three of three) and in renal cell carcinomas (six of eight).