Blood group-related antigen expression in normal and metaplastic human upper gastrointestinal mucosa

Lewis antigen expression in upper gastrointestinal epithelium was studied using four monoclonal antibodies to determine the relationship between aberrant differentiation and antigen expression. Specific patterns of type 1 and type 2 Lewis blood group antigen expression were found in the surface and glands of the esophagus, gastric fundus, and duodenum. In biopsy specimens of Barrett's esophagus, gastric fundic-type columnar metaplasia expressed Lewis antigens indistinguishable from those in the normal stomach. In Barrett's junctional and specialized columnar metaplasia, Lewis a antigen was aberrantly expressed on the surface in secretors and in the glands independent of secretor state. Lewis x reactivity was markedly diminished in the glands of Barrett's junctional and specialized columnar epithelium irrespective of secretor state. There was no significant aberrancy observed in the expression of Lewis b and y antigens. The observed aberrant expression of Lewis antigens may be caused by an altered differentiation program in Barrett's metaplastic epithelium and may define a role for these glycoconjugates in the process of metaplasia and carcinogenesis in Barrett's epithelium.