Pathogenic implications of interleukin-8 activity and bacterial phenotype in antral gastritis associated with...

Helicobacter pylori (Hp) infection is characterized by an intense inflammatory infiltrate in the gastric mucosa, which is chemoattracted by different cytokines. Interleukin-8 (IL-8) seems to play an important role in the recruitment of circulating neutrophils, and modulation of IL-8 secretion seems to be a strain marker. This study was designed to examine IL-8 concentrations in the gastric mucosa and their relationship with H. pylori phenotype and histologic findings.

Gastric biopsies were obtained from the antrum and corpus in 106 patients (69 Hp-positive and 37 Hp-negative). IL-8 levels in the gastric mucosa were analyzed by ELISA and Hp phenotype was determined with a western blot test.

75% of H. pylori strains were CagA+ and 54.2% were VacA+. The Houston classification was used for histologic findings. No association between gastric atrophy or intestinal metaplasia and Hp phenotype was found. The highest IL-8 levels were found in CagA+ infected gastric mucosa, but the difference with respect to infection by a VacA+ strain was not statistically significant. IL-8 levels were highest when neutrophils were the predominant cell in the gastric inflammatory infiltrate (p < 0.05). IL-8 levels were higher in patients with atrophic gastritis than in patients with nonatrophic gastritis (p < 0.05).

In patients with H. pylori infection, IL-8 levels are higher than in Hp-negative patients regardless of Hp phenotype. There is an association between IL-8 and a neutrophilic infiltrate. Perpetuation of a chronic infiltrate could lead to more severe lesions such as atrophic gastritis or intestinal metaplasia, as deduced from the IL-8 levels found in these types of lesion.