Characterization of Lymphocytic Subsets and Cytokine Production in Gastric Biopsy Samples from Helicobacter pylori Patients

Background: This study characterized the phenotypic subsets of isolated gastric lymphocytes and the cellular immune response in cultured gastric biopsy specimens. Methods: Endoscopy specimens from 40 Helicobacter pylori-positive and 40 H. pylori-negative patients were studied. a) Isolated gastric lymphocytes were analysed for CD4+, CD8+ T-lymphocyte subsets, activated T cells, and natural killer cells on a fluorescence-activated cell sorter, using monoclonal antibodies. b) The supernatant of cultured gastric biopsy specimens were assayed for interleukin (IL)-2, IL-4, and IL-6 levels. Results: In H. pylori-positive patients there was (a) a decrease in CD4+/CD8+ T cells, no change in activated T cells, and an increase in natural killer cells, and (b) no change in IL-2 levels and a significant increase in IL-4 and IL-6 levels. Conclusions: There is an increase in CD8+ lymphocytes and natural killer cells, and the observed increase in IL-4 and IL-6 might be important in H. pylori-associated gastritis.