Relationship between Helicobacter pyloriinfection and gastric metaplasia in the mucosa of duodenal bulb

Objective To investigate the relationship between Helicobacter pylori(H. pylori)infection and gastric metaplasia in the duodenal bulb and to pursue whether they play critical roles in pathogenesis of duodenitis and ulcer.Methods Eighty-two archive paraffin blocks of duodenal biopsy were obtained. All sections were stained with H-E, AB/PAS and Giemsa stains for histology, gastric metaplasia and H. pyloriassessment. There were 10 patients with normal duodenum, 47 with duodenitis and 25 with ulcer confirmed by endoscopy. Results There was a discrepancy in diagosis of the normal duodenal bulb mucosa between endoscopy and histopathology. Mild to moderate infiltration of inflammatory cell without gastric metaplasia were detected in 60% of cases with the normal duodenal bulb mucosa judged by endoscopy. Gastric metaplasia in duodenal bulb was the major phenomena in the patients with duodenitis and ulcer (37/82, 45%). H. pyloriinfection in the duodenal bulb always appeared in areas of gastric metaplasia. H. pyloriwas identified in 28 out of 37 (76%) cases in the gastric metaplasia mucosa. The prevalence of gastric metaplasia in the duodenal bulb between the patients with ulcer (72%) and duodenitis (40%) was significantly different (P=0.0078). The frequency of H. pyloricolonization was higher in the patients with duodenal ulcer (89%) than the patients with duodenitis (63%), but did not reach statistical significance(P=0.062). H. pyloriinfection was also higher in the ulcer patients with active, healed or scar stage, being 9/10, 5/6 and 2/2, respectively. Conclusions There is a difference in the frequency of H. pyloricolonization in the gastric metaplasia mucosa in the patients with ulcer and duodenitis, which suggests that infection with H. pylorimay play an important role in ulcer recurrence.