ISMJ

Background: H. pylori infection is associated with gastritis and marked infiltration of the gastric mucosa by inflammatory cells secreting of several cytokines that contribute to maintain and expand the local inflammation. Different clinical expressions of the infection may reflect different patterns of cytokine expression. Interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-17, IL-23, and IL-18 have been reported to be involved in H. pylori-induced gastric mucosal inflammation, but the details and relation to different patterns of inflammation remain unclear. Materials and Methods: Analysis of IL-18 RNA transcripts was performed by real-time PCR. Total RNA was extracted from gastric biopsies of 56 H. pylori-infected patients, 50 H. pylori-negative patients with gastritis, by biozol reagent according to the manufacturer's instructions. CDNA was synthesized from 1 mg of total RNA using First Strand cDNA Synthesis Kit (fermentas) and 3 μL cDNA was amplified by PCR using the 2x Rotor-Gene Probe PCR Master Mix (QIAGEN) and specific primers for each cytokine and β-actin. Results: IL-18 mRNA expression was significantly increased in biopsies of H. pylori-infected patients compared to H. pylori-uninfected individuals. Conclusion: IL-18 may play an important role in the inflammatory response and promoting gastric Th1 responses to H. pylori colonization, and may ultimately influence the outcome of H. pylori-associated diseases that arise within the context of gastritis.