Permanent changes in intestinal intraepithelial lymphocytes have been observed in coeliac patients. The aim of this investigation was to study small intestinal intraepithelial lymphocytes by using flow cytometry and to evaluate its diagnostic value in coeliac disease. Three-colour flow cytometry analyses were performed on isolated epithelial cells of 117 intestinal biopsies obtained from 113 children (54 coeliac disease, 4 other enteropathies, 18 Helicobacter pylori associated gastritis and 37 normal controls). A multiple logistic regression model was developed to select the best intraepithelial lymphocytes subset predictor of coeliac disease. Coeliac patients had significant higher levels of T cell receptor gammadelta intraepithelial lymphocytes than control patients (p < 0.01), H. pylori patients (p < 0.01) and other enteropathies (p < 0.05). The density of CD3-/CD7+ intraepithelial lymphocytes, a intraepithelial lymphocyte subset poorly characterized by immunohistochemical methods, was significantly lower in coeliac patients than in the control group (p < 0.01). H. pylori group (p < 0.01) and other enteropathies (p < 0.01). Both changes remained altered independent of the coeliac patient's diet. The data were used on a logistic regression analysis in order to calculate sensitivity [94.4%; 95% confidence interval (CI) 83.7-98.6%], specificity (94.9%; 95% CI 84.9-98.7%) and likelihood ratio for a positive test 18.5 (95% CI 6.1-55.8) in the diagnosis of coeliac disease.
Conclusion: Changes in T cell receptor gammadelta and CD3-/CD7+ intraepithelial lymphocytes subsets are permanently observed in paediatric coeliac disease. Their assessment, by three-colour flow cytometry on routine diagnostic biopsies, permits a better characterization of coeliac enteropathy and represents a valuable procedure to identify coeliac patients with different clinical presentations.