Objective: To examine the expression of adhesion molecules on gastric intra-epithelial lymphocytes (IELs) from patients infected with Helicobacter pylori.
Design: The expression of adhesion molecules and T-cell activation markers by gastric IELs from patients with gastritis or duodenal ulceration was examined using two-colour flow cytometry. Ten of the patients were H. pylori positive and eight were H. pylori negative.
Results: Expression of lymphocyte function-associated antigen-1 (LFA-1) on IELs was significantly lower (P < 0.05) in patients with H. pylori infection than in patients negative for H. pylori. There were no significant differences in the expression on IELs of intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), human mucosal lymphocyte (antigen)-1 (HML-1), very late antigen-4 (VLA-4) or CD43 between H. pylori-positive and H. pylori-negative individuals. In addition, the transferrin receptor, a maker associated with proliferation and activation, was found on a small population of IELs from H. pylori-positive individuals.
Conclusion: A reduction in the expression of LFA-1 has previously been reported on activation of IELs. The finding of reduced LFA-1 expression and increased transferrin receptor expression on IELs from H. pylori-positive individuals suggests that activation of these cells is associated with H. pylori infection.