Gastric metaplasia in the duodenal bulb shows increased mucosal interleukin-8 activity in Helicobacter pylori-positive duodenal ulcer patients

Background: Although increased levels of interleukin (IL)-8 are known to be associated with infiltration of neutrophils in the gastric mucosa with Hel icobacter pylori infection, no study has investigated the relationship betw een local IL-8 levels and neutrophil infiltration in the duodenal mucosa of patients with duodenal ulcer (DU). Methods: Duodenal mucosal biopsy specim ens with and without gastric metaplasia (GM) were obtained from patients wi th DU and controls with an endoscopic methylene blue (MB) staining method. Levels of IL-8 secreted in the organ cultures of biopsy specimens were meas ured with an enzyme-linked immunosorbent assay. The number of myeloperoxido se-positive neutrophils infiltrating the lamina propria was determined in i mmunohistochemically stained tissue sections. Results: Histologic assessmen t showed that there was a strong correlation between the absence of endosco pic MB staining and the extent of GM. The levels of IL-8 in both duodenal a nd antral mucosal tissues were significantly higher in patients with H. pyl ori infection than in those without infection. In patients with DU the duod enal mucosal tissues with GM (MB-unstained mucosa) showed significantly hig her levels of IL-8 than those without GM (MB-stained mucosa) or the antral mucosa. The number of neutrophils showed similar variations among DU and co ntrol patients with a positive correlation with IL-S activity. The levels o f IL-I and the number of neutrophils decreased after H. pylori eradication in both duodenal and antral mucosal tissues, and these changes were more re markable in the duodenal mucosal tissues with GM. Conclusions: Increased IL -8 activity in the duodenal mucosa with GM may be important for ulcerogenes is in H. pylori-positive DU patients.