Cytokine gene expression in the gastric mucosa: its role in chronic gastritis.

There have been few studies of cytokine expression in the gastric mucosa of patients with chronic gastritis. In the present study, to elucidate the expression of cytokines in the gastric mucosa and the immunopathological roles played by these cytokines in chronic gastritis, we investigated cytokine gene expression, by reverse transcription polymerase chain reaction, in gastric biopsy specimens obtained from 29 endoscopically normal patients with chronic gastritis. The cytokines examined and the mRNA positivity were: interleukin (IL)-1 beta (21%), IL-2 (0%), IL-3 (7%), IL-4 (41%), IL-5 (17%), IL-6 (53%), IL-8 (98%), interferon gamma (IFN-gamma) (69%), and tumor necrosis factor alpha (TNF-alpha) (24%). Although the histological severity of the gastritis was closely associated with Helicobacter pylori infection, the positivities of these cytokine mRNAs did not show a relationship with either H. pylori infection or with histological inflammation. Our findings suggest that the gastric mucosa responds to all exogenous antigens, including H. pylori, in the same fashion immunologically, and that these cytokines do not contribute to the induction of inflammation associated with H. pylori infection.