Expression of proinflammatory and Th1 but not Th2 cytokines is enhanced in gastric mucosa of Helicobacter pylori infected children.

BACKGROUND: Helicobacter pylori-induced gastric inflammation is thought to be largely regulated by cytokines. PATIENTS AND METHODS: The expression of interferon-gamma, interleukin-12, interleukin-4, interleukin-10, interleukin-8, and interleukin-17 mRNA was examined on gastric mucosal samples from 24 children by semiquantitative reverse transcription polymerase chain reaction and southern blotting. Biopsy-based tests, serology, and urea 13C breath test were used to assess Helicobacter pylori status. Gastric biopsies were also evaluated for bacterial density, chronic inflammation, and acute inflammatory activity. RESULTS: Interferon-gamma, interleukin-12, interleukin-8 and interleukin-17 expression was higher in Helicobacter pylori-infected (n=13) than uninfected (n=11) children. Conversely, interleukin-4 and interleukin-10 expression did not differ between Helicobacter pylori-infected and uninfected children. In Helicobacter pylori-infected children, interferon-gamma, interleukin-12, interleukin-8 and interleukin-17 expression correlated with bacterial density, and Interferon-gamma and interleukin-12 expression with chronic inflammation score. CONCLUSIONS: The findings of this study indicate that, in children, Helicobacter pylori-induced inflammatory response would favour production of proinflammatory cytokines and development of cell-mediated immunity, namely Th1 response.