Effect of cagE gene on Helicobacter pylori-associated gastritis and levels of interleukin-8

Objective: To investigate the status of cagE gene of Helicobacter pylori(H. pylori) isolated from patients with various gastrointestinal diseases and its relationship with the pathological inflammation grade and levels of IL 8 in the gastric mucosa and IL 8 secretion in gastric epithelial cells stimulated by H. pylori . Methods: cagE was amplified by polymerase chain reaction (PCR) in 145 clinical isolates. The inflammation grade of gastric mucosa was evaluated pathologically. IL 8 levels of gastric mucosa and IL 8 concentration of the supernatant of the cocultured SGC 7 901 cells and H. pylori was assayed by enzyme linked immunosorbent assay (ELISA). Results: cagE was positive in 79.3% of all the H. pylori strains. The mean score of the cagE positive gastritis in the antrum and corpus was (1.865±0.335) and (1.759±0.310). Meanwhile, the cagE negative grade was (1.689±0.294), (1.608±0.284). There was no significant difference ( P >0 05). The mean levels of IL 8 in cagE positive group in antrum and corpus were (390.6±101.4) pg/mg and (368.6±91.2) pg/mg; and cagE negative group were (328.6±102.8) pg/mg and (332.6±96.7) pg/mg. IL 8 in SGC7901 cells induced by cagE positive and negative group averaged (789.5±146.7) pg/ml and (757.6±136.4) pg/ml. There was still no significant difference( P >0.05). Conclusion: Positive rate of cagE is very high in Chinese patients regardless of the clinical outcome. And there was no direct relationship between cagE gene and the inflammation grade and IL 8 levels of H. pylori infected gastric mucosa and IL 8 secretion in gastric epithelial cells stimulated by H. pylori .