Duodenal mucosa FOXP3 expression in different etiologies of lymphocytic duodenosis.

Background/aims: In celiac disease there is an increase of lymphocytes expressing FOXP3 in the intestinal mucosa associated with varying degrees of villous atrophy. Our aim was to evaluate FOXP3 expression in duodenal mucosa with lymphocytic enteritis according to aetiology and correlation with lymphocytes T-γδ.

Methods: We compared three adult patient groups suffering lymphocytic enteritis: celiacs following a gluten-free diet (n=12), first-degree relatives of celiac patients with genetic risks (n=14) and patients with functional dyspepsia (n=14), along with a control group not suffering from duodenal enteritis (n=16). The population of duodenal lymphocytes was analysed by immunohistochemistry assays for CD3+ characterisation and FOXP3 expression. Quantification of lymphocytes T-γδ in duodenal mucosa was performed by flow cytometry in fresh tissue samples.

Results: Presence of lymphocytes T-γδ was significantly higher in the group of celiac individuals compared to the group of relatives of these individuals (37.44 vs 5,52: p<0.0001) and the group with functional dyspepsia (37.44 vs 11.76: p=0.008). FOXP3 expression was also significantly higher in the celiac group than in the groups of relatives (18.85 vs 6.31; p=0.001) and functional dyspepsia patients (18.85 vs 7.61; p=0.023). The proportion of lymphocytes T-γδ and FOXP3- expressing lymphocytes was similar in the control group to that in the relatives or functional dyspepsia groups.

Conclusions: Lymphocytic enteritis associated to celiac disease shows an increase of FOXP3 expression and lymphocytes T-γδ that is not detected in other etiologies of enteritis.