The role of Helicobacter pylori infection in the pathogenesis of gastritis.

We conducted a prospective study to evaluate the relationship between H. pylori infection and gastritis in a Japanese population. The study population consisted of 92 patients with endoscopically proven gastritis. Biopsy specimens were taken from the gastric mucosa from the corpus and antrum according to the Sydney system for the new classification of gastritis. H. pylori was histologically found in 84.3% of patients for mononuclear (MN) cell infiltration and in 88.1% of those positive for polymorphonuclear (PMN) cells. H. pylori was not found in any of nine patients without MN cell infiltration (P < 0.001), while 68.8% of patients without PMN cell infiltration were positive for H. pylori (P < 0.03). The frequency of MN cell infiltration in H. pylori-positive patients was significantly higher than that in H. pylori-negative patients (100% vs 65.4%; P < 0.001). The frequency of PMN cell infiltration in H. pylori-positive patients was also significantly higher than that in H. pylori-negative patients (54.5% vs 23.1%; P < 0.01). The incidence of MN cell infiltration in the antrum was significantly higher than that in the gastric corpus in H. pylori-positive gastritis patients (93.2% vs 65.1%; P < 0.001). The incidence of PMN cell infiltration was also higher in the antrum than in the corpus in H. pylori-positive gastritis patients, although the difference was not significant (42.0% vs 31.7%).(ABSTRACT TRUNCATED AT 250 WORDS)