CHARACTERIZATION OF LYMPHOCYTIC INFILTRATES IN HELICOBACTER-PYLORI-ASSOCIATED GASTRITIS

Background: This study evaluated the specific subset composition of ly mphocytes present in Helicobacter pylori-associated gastritis (HAG), s ince reports so far have led to inconclusive and conflicting results. Methods: Endoscopic biopsy specimens from 56 patients were studied by quantitative immunohistochemistry using monoclonal antibodies against the lymphocyte markers CD3, CD22, CD4, CD8, CD45RO, CD103, TCR alpha/b eta, and TCR gamma/delta. Lamina propria and intraepithelial compartme nts were evaluated separately. Grade, activity, and density of bacteri al colonisation were assessed histologically and with Warthin-Starry s tain. Results: Evaluation showed a significant increase in CD4+, CD45R O+, TCR alpha/beta+ activated lamina propria lymphocytes in HAG which correlated with grade and activity of gastritis and degree of bacteria l colonisation, whereas subsets of intraepithelial lymphocytes did not change significantly. TCR gamma/delta+ T cells were not found to be i ncreased in HAG. Conclusions: Selective expansion of CD4+, CD45RO+ mem ory-type T cells could reflect an antigen-specific and/or chemokine-me diated effect in HAG. Locally produced CC chemokines such as RANTES ha ve been detected in HAG.