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

AIM:To investigate the ABH and Lewis antigen expres-sion in erythrocytes,saliva and gastric epithelium,aswell as the association between H pylori and the pres-ence of gastric epithelial lesions.METHODS:The distribution of ABH and Lewis bloodgroup antigens in erythrocytes,saliva and gastric mu-cosa of H pylori-infected gastric ulcer patients was ana-lyzed.Forty-two patients with gastric ulcer were studied,and fifty healthy individuals were used as control group.The blood group antigens were determined by directhemagglutination,dot-ELISA and immunohistochemi-cal methods in erythrocytes,saliva and gastric mucosaspecimens,respectively.Diagnosis for H pylori infectionwas performed by conventional optical microscopy andELISA.RESULTS:A higher seroprevalence of IgG H pylori spe-cific antibodies was observed in gastric ulcer patients(90%)compared to the control group(60%).We ob-served a significant increase of phenotypes O,A2andLewis b in H pylori-infected patients.The expression ofthese antigens had progressive alterations in areas of ul-cerous lesions and intestinal metaplasia. CONCLUSION:ABH and Lewis blood group antigensare a good indicator for cellular alterations in the gastricepithelium.