Relationship between Helicobacter pylori infection and gastric metaplasia in the duodenal bulb in the pathogenesis of duodenal ulcer

Background: The aim of this study was to determine whether the amount of He licobacter pylori and the extent of gastric metaplasia in the duodenal muco sa Flay critical roles in the pathogenesis of duodenal ulcer. Methods: Duodenal and gastric biopsy specimens were obtained from H. pylori -positive patients with duodenal ulcer, gastric ulcer or chronic gastritis. The extent of gastric metaplasia was evaluated histologically and endoscop ically using the methylene blue test. In this study, we performed competiti ve polymerase chain reaction? a highly sensitive and quantitative method fo r determining the amount of H. pylori gastric and duodenal mucosa. The prev alence and extent of gastric metaplasia and the amount of H, pylori in the duodenal bulb in the three patient groups were compared. The correlation be tween the amount of H. pylori in the duodenum and gastric antrum and extent of gastric metaplasia were also determined. Results: The prevalence and extent of gastric metaplasia and the amount of H. pylori in the duodenal bulb in patients with duodenal ulcer were much hi gher than in patients with gastric ulcer or chronic, gastritis. a positive correlation was found between the amount of H. pylori in the duodenum and t he extent of gastric bulb and that in the antrum. Conclusions: The findings of this study indicate that H. pylori colonizatio n in the: duodenal bulb may play a critically important rule in the pathoge nesis of duodenal ulcer and that the amount of H. pylori in the duodenal bu lb may be related to the amount of H. pylori in the gastric antrum and the extent of gastric metaplasia in the duodenal bulb.