The aims of this study are 1) to determine the cytokines produced by both Th1 and Th2 subsets in gastric antral biopsy specimens from Taiwanese patients before and after anti H. pylori therapy; 2) to obtain a detailed phenotypic characterization and distribution pattern of mucosal lymphocytes in H. pylori-associated gastritis and to define possible contributing immune mechanisms responsible for the chronicity of the disease and its associated lesions.

Helicobacter pylori, a Gram-negative spiral bacterium, has been first isolated from a patient with chronic active gastritis since 1982. Recent studies strongly suggest that chronic infection with H. pylori is tightly associated with chronic gastritis, peptic ulcer, and gastric carcinoma. However, only a minority of infected people develop signs and symptoms of gastric pathology. Thus, both host and microbial factors may lead to different outcomes of infection. In spite of high prevalence in general population and increasing clinical attention has been paid on this infection, the knowledge of pathogenic mechanism of H. pylori infection is still limited and little is known about the role of host immune response in the pathogenesis of disease.The aims of this study are 1) to determine the cytokines produced by both Th1 and Th2 subsets in gastric antral biopsy specimens from Taiwanese patients before and after anti H. pylori therapy; 2) to obtain a detailed phenotypic characterization and distribution pattern of mucosal lymphocytes in H. pylori-associated gastritis and to define possible contributing immune mechanisms responsible for the chronicity of the disease and its associated lesions.

Inclusion Criteria:

• H. pylori infection

Exclusion Criteria:

• none