ABSTRACT
Objective to study the characteristic typing of Helicobacter pylor(Hp)phenotypes and their sub-phenotypes in the patients with duodenal bulb ulcers(DU),and its clinical significance. Methods One hundred thirty-five cases with DU and 140 casses with chronic superficial gastritis were enrolled in this study. Determinations of serum cytotoxin-associated gene protein A (CagA),vacuolating cyto-toxin A(VacA),urease (Ure)A,UreB antibodies and their sub-phenotypes by immunoblotting were carried ou. Results Positive rate of middle-phenotypes of Hp infection in DU was significantly lower than that in chronic superficial gastritis (21.5%vs 27.9%,P<0.05).VacA and CagA antibodies might express alone. There had no significant difference among the expression rate of phenotype CagA, VacA antibodies and their sub-phenotype. But expression rate of Ure antibodies in Du was higher than that in chronic superficial gasstritis (P<0.05).In infection of Hp type I, the expression rate of sub-phenotypes 30ku UreA in DU was hronic superficial gastritis (P<0.05). Conclusions The VacA is not for expressing higher than that inpression of Hp exists many sub-phenotypes ( 128 ku CagA 116 ku CagA, 95 ku VacA, 91 ku CagA 0 ku UreA),and it probably causes formation of DU by comprehensive effect. Hp type I with sub phenotype expressing 30 ku Urea may be more pathogenic in DU formation.