ABH and Lewis antigen distributions in blood, saliva and gastric mucosa and Hpylori infection in gastric ulcer patients

AIM： TO investigate the ABH and Lewis antigen expression in erythrocytes, saliva and gastric epithelium, as well as the association between H pylori and the presence of gastric epithelial lesions. METHODS： The distribution of ABH and Lewis blood group antigens in erythrocytes, saliva and gastric mucosa of Hpylori-infected gastric ulcer patients was analyzed. Forty-two patients with gastric ulcer were studied, and fifty healthy individuals were used as control group. The blood group antigens were determined by direct hemagglutination, dot-ELISA and immunohistochemi- cal methods in erythrocytes, saliva and gastric mucosa specimens, respectively. Diagnosis for H pylori infection was performed by conventional optical microscopy and ELISA. RESULTS： A higher seroprevalence of IgG H pylori specific antibodies was observed in gastric ulcer patients （90%） compared to the control group （60%）. We observed a significant increase of phenotypes O, A2 and Lewis b in H pylori-infected patients. The expression of these antigens had progressive alterations in areas of ulcerous lesions and intestinal metaplasia. CONCLUSION： ABH and Lewis blood group antigens are a good indicator for cellular alterations in the gastric epithelium.