COX-2 expression in the H. pylori infected gastric mucosal epithelia and its significance

Objective To study COX-2 expression in H. pylori infected gastric mucosal epithelia and its significance in the carcinogenesis of the stomach. Methods Rapid urease test and histological examination with basic magnenta staining were used to assess the status of H.pylori infection in the stomach. COX-2 was detected immunohistochemically. Results COX-2 immunostaining was positive in 1 out of 12 cases with H. pylori-negative gastric mucosa and also in 1 out of 10 cases with H. pylori-positive gastric mucosa without macroscopic alterations, while COX-2 expression was found to be positive in 5 out of 9 cases with H. pylori related superficial gastritis with mucosal erosions. COX-2 expression was detected in 5 out of 10 cases with H. pylori-positive mild atrophic gastritis, 8 out of 10 cases with H. pylori-positive moderate-severe atrophic gastritis and intestinal metaplasia, and 6 out of 8 cases with H. pylori-positive moderate-severe dysplasia. COX-2 expression was positive in 22 out of 32 cases of gastric cancer. Conclusion H. pylori may induce COX-2 expression of gastric mucosal epithelia in chronic superficial gastritis, which is related to the development of mucosal injury. According to gastric mucosal carcinogenesis pattern up-regulaton of COX-2 expression is associated with gastric mucosal carcinogenesis, and involved in the early development of premalignant lesions.