Helicobacter pylori cagA gene and expression of cytokine messenger RNA in gastric mucosa

Gastroenterology. 1996 Jun;110(6):1744-52. doi: 10.1053/gast.1996.v110.pm8964399.


Background & aims: Helicobacter pylori strains possessing the cagA gene are thought to be associated with gastroduodenal diseases. Furthermore, some cytokines are considered to play a role in gastric mucosal inflammation. The aim of this study was to investigate the relationship between cagA gene and cytokine messenger RNA (mRNA) expression in gastric mucosa.

Methods: In 160 patients, the cagA gene was detected using polymerase chain reaction, and interleukin (IL) 1 beta, IL-6, IL-7, IL-8, IL-10, and tumor necrosis factor (TNF) alpha mRNA were detected using reverse-transcription polymerase chain reaction.

Results: Specimens infected with cagA gene-positive strains (cagA-positive specimens) had significantly more severe infiltration of polymorphonuclear leukocytes and mononuclear cells than those infected with cagA gene-negative strains (cagA-negative specimens). Levels of expression of IL-6, IL-7, IL-8, IL-10, and TNF-alpha mRNA were significantly higher in H. pylori-positive than H. pylori-negative patients. Furthermore, the level of IL-8 mRNA expression was significantly higher in cagA-positive than cagA-negative specimens.

Conclusions: cagA-positive strains induce the expression of IL-8 mRNA, suggesting that IL-8 may play important roles in the pathogenesis of gastroduodenal diseases associated with H. pylori infection.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Base Sequence
  • Cytokines / genetics*
  • Female
  • Gastric Mucosa / metabolism*
  • Gastric Mucosa / pathology
  • Gastric Mucosa / physiopathology*
  • Gastroscopy
  • Genes*
  • Helicobacter Infections / drug therapy
  • Helicobacter Infections / metabolism
  • Helicobacter Infections / pathology
  • Helicobacter pylori / genetics*
  • Humans
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Oligonucleotide Probes / genetics
  • Polymerase Chain Reaction
  • RNA, Messenger / metabolism*
  • Transcription, Genetic


  • Cytokines
  • Oligonucleotide Probes
  • RNA, Messenger