LACK OF CORRELATION BETWEEN LEWIS ANTIGEN EXPRESSION BY HELICOBACTER-PYLORI AND GASTRIC EPITHELIAL-CELLS IN INFECTED PATIENTS

Background & Aims: Lewis antigens are expressed by both human gastric epithelial tissue and Helicobacter pylori. We examined Lewis antigens expressed by gastric epithelium and by H. pylori isolated from the cor responding biopsy tissue. Methods: H. pylori Lewis expression was dete rmined by enzyme immunoassays, and immunoelectron microscopy was used to confirm the Lewis antigens on some H. pylori cells and in some biop sy specimens. Histopathology using identical monoclonal antibodies spe cific for Lewis A, B, X, and Y antigens was used to detect these antig ens in 24 gastric biopsy specimens. Results: We identified Lewis Y in 100%, Lewis X and Lewis B in 95.8%, and Lewis A in 87.5% of biopsy spe cimens. In H. pylori, 87.5% expressed Lewis Y, 79.2% Lewis X, and 4.2% tone strain) Lewis B. No Lewis A was detected. Antibody specific for Lewis X labeled the bacteria and associated adhesion pedestal. The cag A gene was present in 92% of strains. Conclusions: There was no direct relationship between Lewis antigen expression by H. pylori and gastri c epithelial cells in infected patients. Expression of Lewis X and Lew is Y by H. pylori suggests the possibility of their requirement for es tablishment and/or maintenance of infection. An immunoelectron microgr aph of H. pylori interaction with the gastric epithelial adhesion pede stal suggests a tentative role for Lewis X in the adhesion process.