Lack of association between gastric phenotypic expression of blood group antigens with H. Pylori infection and fundic gland polyps

Abstract

Blood group antigen Lewis B as a potential Helicobacterpylori (HP) receptor in the gastric epithelial cells has been questioned. Gastric epithelial cell expression of blood group antigens may differ from the conventional erythrocyte phenotypic expression in the same individual. We reported a striking lack of HP infection in patients with gastric fundic gland polyps (FGP)(Gastroenterology 1997; 112:A88). Now we determined phenotypic expression of blood group antigens, H type 2, Lewis A and Lewis B in epithelial cells of gastric biopsy specimens immun0histochemically using monoclonal antibodies. Twenty three FGP cases with at least one other paired biopsy from non-polypoid gastric mucosa (Group I, all HP negative), 24 HP negative cases (Group 11) and 28 HP positive cases (Group III) were compared. There were no discordant antigenic expressions in all 23 FGP cases between FGP mucosa and non-polypoid mucosa. Unlike red blood cell phenotypes, coexpression of Lewis A and B was most common in the gastric epithelial cells of all groups (over 50%). Regardless of the presence or absence of H antigen expression, both Lewis A and B negative patterns were not observed. There were no statistical differences between the groups and gastric blood group antigen phenotypic expression.