Lymphocytic gastritis in pediatric celiac disease -- immunohistochemical study of the intraepithelial lymphocytic component.

BACKGROUND

Lymphocytic gastritis (LG) is defined by the recognition of >25 intraepithelial lymphocytes (IEL) per 100 surface epithelial cells. Approximately 50% of children with celiac disease (CD) present LG, which mainly involves the gastric antrum and disappears after a gluten-free diet. This intraepithelial population of lymphocytes has not been immunophenotypically characterized for this age group.

MATERIAL/METHODS: We immunohistochemically analyzed 5 formalin-fixed, paraffin embedded biopsies of LG in children with untreated celiac disease using a panel of antibodies. All patients were diagnosed on the bases of clinical, laboratory and histopathological data.

RESULTS

All showed similar results. IEL proved to be CD45RO, CD3, CD7, CD8, and Tia-1 positive, while CD4, CD20, CD79a, CD56, CD57, granzyme B, perforin, TCR gamma-delta, TCR beta (V-19), CD95 (FAS), CD95-L (FAS-L) and HLA II were negative. Many IEL were in apoptosis. CD45RO, CD3 and CD7 presented as membranous staining, while Tia-1 resulted in intracytoplasmic granular brown dots. In 3 cases there were rare lymphocytes with granzyme B-positive granules localized to the lamina propria. None presented Helicobacter pylori -like organisms at the luminal surface.

CONCLUSIONS

LG associated with CD in children contains a peculiar CD8+ intraepithelial T-lymphocyte population which immunohistochemically lacks perforin and granzyme B, undergoes apoptosis, and is not associated with substantial damage to the epithelial cells. Our results fit with those reported in adults except for the negative results for granzyme B. The findings appear disparate from the ones described in the duodeno-jejunal mucosa in untreated celiac disease.