Proinflammatory Cytokine IL-17 Shows a Significant Association with Helicobacter pylori Infection and Disease Severity

BACKGROUND: The pro- and anti-inflammatory cytokines play an important role in the immune response against H. pylori infection. The proinflammatory cytokines of Th17 cells have been suggested to play a major role in H. pylori infection and resulting gastric inflammation. OBJECTIVE: The objective of this study was to compare the expression of selected inflammatory cytokines (IL-10, IL-17, IL-21, IL-23, and TNF-α) in H. pylori-infected patients and healthy controls and to understand their association with H. pylori infection and disease severity. RESULTS: The expression levels of IL-17 and IL-23 were significantly higher in H. pylori-infected patients. The expression of IL-21 was also higher in H. pylori-positive patients but there was no significant association with infection. IL-17 expression showed a significant increase with the severity of chronic gastritis. CONCLUSION: The proinflammatory cytokine, IL-17, shows a significant association with H. pylori infection and disease severity in a Sri Lankan dyspeptic patient population.