Helicobacter pylori cag pathogenicity island is associated with enhanced interleukin-8 expression in human gastric mucosa

Dig Liver Dis. Aug-Sep 2000;32(6):458-67. doi: 10.1016/s1590-8658(00)80001-8.


Background: In vitro studies showed that Helicobacter pylori strains carrying the cag pathogenicity island are able to induce epithelial secretion of Interleukin-8.

Aims: To evaluate the assessment of cag pathogenicity island and the expression of Interleukin-8 in the gastric mucosa of Helicobacter pylori-infected patients and correlate these data with the activity of gastritis and Helicobacter pylori density.

Methods: cag status was determined by polymerase chain reaction directly on gastric biopsies from 13 Helicobacter pylori+ patients with non-ulcer dyspepsia and 13 Helicobacter pylori+ with duodenal ulcer. Interleukin-8 gene transcription and protein expression were analysed by in situ hybridization and immunofluorescence, respectively. Gastritis activity and Helicobacter pylori density were also investigated.

Results: cag was present in 20/26 of Helicobacter pylori+ patients: in 7/13 non-ulcer dyspepsia (53.8%] and in 13/13 duodenal ulcer patients (100%), (p<0.05). Interleukin-8 mRNA and protein expression in epithelial and inflammatory cells was higher in cag+ than in cag- patients (p<0.005). Gastritis activity significantly correlated with cag (p<0.05) and Interleukin-8 expression (p<0.005]. Helicobacter pylori density was enhanced in cag+ [p<0.005] and correlated with Interleukin-8 expression (p<0.0051.

Conclusions: The present study demonstrates that in Helicobacter pylori-infected human gastric mucosa, cag+ infection is associated with enhanced Interleukin-8 expression, higher levels of active gastritis and bacterial density, and presence of duodenal ulcer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Bacterial*
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics*
  • Duodenal Ulcer / microbiology*
  • Gastric Mucosa / microbiology
  • Gastritis / microbiology
  • Gene Expression Regulation
  • Helicobacter Infections / microbiology*
  • Helicobacter pylori / genetics*
  • Helicobacter pylori / pathogenicity*
  • Humans
  • In Situ Hybridization
  • Interleukin-8 / biosynthesis*
  • Polymerase Chain Reaction


  • Antigens, Bacterial
  • Bacterial Proteins
  • Interleukin-8
  • cagA protein, Helicobacter pylori