Local cellular immune response in Helicobacter pylori associated type B gastritis--selective increase of CD4+ but not gamma delta T-cells in the immune response to H. pylori antigens.

During recent years the infectious etiology of the majority of cases of chronic active type B gastritis and peptic ulcers has become increasingly evident. The chronicity of clinical symptoms and histopathological features such as numerous mucosal lymphocytic aggregates have implied a role of the specific cellular immune system. Whereas in Type A chronic active gastritis a pathogenetic role of lymphocytes and their target structures have been amply documented, in chronic active type B gastritis particularly that associated with Helicobacter pylori infection the nature of a specific immune response and its role in the pathogenesis of the epithelial and mucosal lesion has remained obscure. Here we report that CD4+ mucosal lymphocytes appear to selectively accumulate in Helicobacter pylori associated chronically active antral gastritis. Moreover, lamina propria gamma delta T lymphocytes were found to be more frequent in chronic active type B gastritis irrespective of the presence of absence of Helicobacter pylori.