Association between virulence factors of helicobacter pylori and gastric mucosal interleukin-18 mRNA expression in dyspeptic patients

Background: Helicobacter pylori (Hp) infection is associated with gastritis and marked infiltration of the gastric mucosa by several cytokines secreting inflammatory cells that contribute to sustain and expand the local inflammation. Different clinical expressions of the infection may reflect distinctive patterns of cytokine expression. IL-1 beta, TNF-alpha, IL-17 and IL-23 have been reported to be involved in Hp-induced gastric mucosal inflammation, but the details and association to different patterns of inflammation and virulence factors remain unclear. Methods: Total RNA was extracted from gastric biopsies of 51 Hp-infected patients and 44 Hp-negative patients. Mucosal IL-18 mRNA expression in gastric biopsies was determined by Real-Time PCR. Presence of virulence factors was evaluated using PCR. Results: IL-18 mRNA expression was significantly increased in biopsies of Hp-infected patients compared to Hp-uninfected individuals. There was no association between virulence factors and IL-18 mRNA expression. Also severity of mononuclear infiltration was significantly higher in gastritis patients with vacA (m1)-positive compare patients with vacA (m2)-positive. Conclusions: IL-18 may play an important role in the inflammatory response and promote the chronic and persistent inflammatory changes in the stomach. This may ultimately influence the outcome of Hp-associated diseases that arise within the context of gastritis. (C) 2013 Elsevier Ltd. All rights reserved.