Interactions among gastric somatostatin, interleukin-8 and mucosal inflammation in Helicobacter pylori-positive peptic ulcer patients

Background. To investigate whether Helicobacter pylori infection, but not drugs, affects gastric somatostatin, interleukin-8 (IL-8), histological inflammation through eradication therapy, and interactions among these parameters. Methods. Twenty-eight H. pylori-positive patients (21 males; mean age 47.0 years) with either gastric ulcer(GU: n = 11) or duodenal ulcer (n = 17)diagnosed endoscopically were treated with dual therapy. Eradication was defined as negative microbiologic tests and C-13-urea breath test. Levels of antral and gastric juice somatostatin and mucosal IL-8 were measured by radioimmunoassay and enzyme-linked immunosorbent assay, respectively Histology was assessed by the Sydney system. Results. H. pylori was eradicated in 15 patients (10 males, 6 GU) out of 28 (54%). The patients' backgrounds did not affect the eradication of H. pylori. Successes in eradication significantly increased antral and juice somatostatin contents, and dramatically decreased IL-8 levels and histological gastritis. In contrast, persistent H. pylori infection did nor affect somatostatin and histological gastritis. An inverse correlation was present between changes in somatostatin levels and histological activity. No relationship was observed in changed values between antral somatostatin and IL-8. Conclusions. These results indicate that eradication of H. pylori, but not the drugs used, induced an increase in somatostatin levels in the antrum and gastric juice, suggesting a close relationship between N. pylori and gastric somatostatin regulation. A close correlation between an increase in gastric somatostatin levels and the normalization of histological activity was present, suggesting that certain peptide-immune interactions in the gastric mucosa exist in N. pylori infection.