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cagE is a virulence factor associated with Helicobacter pylori-induced duodenal ulceration in children

A S Day1, N L Jones, J T Lynett

  • 1Division of Gastroenterology and Nutrition, Research Institute, Hospital for Sick Children, University of Toronto, Canada.

The Journal of Infectious Diseases
|April 14, 2000
PubMed

Insights

Helicobacter pylori strains with the cagE gene are linked to duodenal ulcers in children. This infection also increases interleukin-8 levels, potentially impacting disease severity.

Area of Science:

  • Microbiology
  • Pediatric Gastroenterology
  • Molecular Biology

Background:

  • Helicobacter pylori (H. pylori) infection is a common cause of gastrointestinal issues in children.
  • Specific virulence factors of H. pylori, such as cagE, may play a role in disease pathogenesis.
  • The association between cagE-positive H. pylori and duodenal ulceration in pediatric populations requires further investigation.

Purpose of the Study:

  • To investigate the association between Helicobacter pylori strains possessing the cagE gene and the occurrence of duodenal ulceration in children.
  • To explore the role of cagE in H. pylori-induced inflammation by examining interleukin-8 (IL-8) production.

Main Methods:

  • Polymerase chain reaction (PCR) was used to detect flaA, cagA, and cagE genes in H. pylori isolates from 29 children.
  • H. pylori isolates were cultured from children diagnosed with duodenal ulcers or gastritis.
  • Infection of gastric cell lines (AGS and KATO-III) with cagE-positive and cagE-negative H. pylori strains was performed to measure interleukin-8 levels.

Main Results:

  • A significant association was found between cagE-positive H. pylori isolates and duodenal ulceration in children (92% vs. 31%, P<.01).
  • Infection with cagE-positive H. pylori strains led to significantly higher levels of interleukin-8 in both AGS (2.3+/-0.1 vs. 1.3+/-0.2 ng/mL, P<.005) and KATO-III (1.5+/-0.3 vs. 0.5+/-0.2 ng/mL, P<.05) cell lines compared to cagE-negative strains.
  • These findings suggest cagE is a key virulence factor in H. pylori-associated duodenal disease.

Conclusions:

  • The presence of the cagE gene in Helicobacter pylori strains is strongly associated with duodenal ulceration in children.
  • Enhanced chemokine (interleukin-8) production induced by cagE-positive H. pylori may contribute to the development and severity of duodenal disease.
  • Targeting cagE or its downstream inflammatory pathways could be a potential therapeutic strategy for pediatric H. pylori infections.

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