Cytokine gene expression in Helicobacter pylori associated antral gastritis.

Infection of the gastric antrum by Helicobacter pylori is characterised by a cellular inflammatory infiltrate. Whether cytokines are involved in the pathogenesis of this gastritis has been investigated by studying the effect of eradicating H pylori on the expression of genes encoding the cytokines interleukin 8 (IL-8) and tumour necrosis factor alpha (TNF-alpha) in the antral mucosa. Gastric antral biopsy specimens were taken from nine patients with duodenal ulcers and cytokine transcripts were identified and quantified by northern blotting. After H pylori had been eradicated the chronic inflammatory infiltrate decreased in all the patients and the polymorphonuclear infiltrate virtually disappeared. Expression of genes also decreased. After eradication, the median TNF-alpha mRNA/rRNA fell to 48% (p = 0.02) and the median IL-8 mRNA/rRNA fell to 5% (p = 0.004) of initial values. These results support the role of increased synthesis of these cytokines in the pathogenesis of the gastritis.