Characterization of Lymphocytic Infiltrates in Helicobacter pylori-Associated Gastritis

Abstract

Background: This study evaluated the specific subset composition of lymphocytes present in Helicobacter pylori-associated gastritis (HAG), since 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, TCRα/β, and TCRγ/δ. Lamina propria and intraepithelial compartments were evaluated separately. Grade, activity, and density of bacterial colonisation were assessed histologically and with Warthin-Starry stain. Results: Evaluation showed a significant increase in CD4+, CD45RO+, TCRα/β+ activated lamina propria lymphocytes in HAG which correlated with grade and activity of gastritis and degree of bacterial colonisation, whereas subsets of intraepithelial lymphocytes did not change significantly. TCRγ/δ+ T cells were not found to be increased in HAG. Conclusions: Selective expansion of CD4+, CD45RO+ memory-type T cells could reflect an antigen-specific and/or chemokine-mediated effect in HAG. Locally produced CC chemokines such as RANTES have been detected in HAG.

Key Words:

• Chemokines
• gastritis
• Helicobacter pylori
• intraepithelial
• lamina propria
• lymphocyte subsets