HIGH PROPORTION OF GRANZYME B-POSITIVE (ACTIVATED) INTRAEPITHELIAL AND LAMINA PROPRIA LYMPHOCYTES IN LYMPHOCYTIC GASTRITIS

Intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LpL s) have not been well studied in gastric mucosa, particularly in lymph ocytic gastritis. Therefore, they were immunohistologically characteri zed with antibodies recognizing CD3, CD8, CD57, T cell-restricted intr acellular antigen (TIA-1), and granzyme B (GrB). The TIA-1 labels cyto toxic granules of resting and activated T-cells, whereas GrB decorates activated cytotoxic T cells. Thirty patients with celiac disease, inc luding 20 taking gluten and 10 on a gluten-free diet, 15 patients with nonceliac disease-associated lymphocytic gastritis, and 20 controls w ere studied. Stained cells were counted and results were given as IELs /100 epithelial cells or percentage of lamina propria cells. Sixty per cent to 90% of CD3(+) IELs and up to 12% of lamina propria cells conta ined TIA-l-positive cytotoxic granules. The number of GrB(+) IELs and LpLs was increased in Helicobacter pylori-positive controls (p < 0.03 vs. H pylori-negative controls) and celiac disease patients taking glu ten (p < 0.05 vs. controls). The highest number of GrB(+) IELs and LpL s was found in nonceliac disease-associated lymphocytic gastritis (p < 0.009 vs. controls, p < 0.05 vs. celiac disease). This study shows th at a high proportion of gastric IELs and LpLs is potentially cytotoxic in nature. Through stimuli not yet identified, a proportion of them b ecomes activated after H pylori infestation and in lymphocytic gastrit is.