Flow-cytometric detection of lactase expression in normal and coeliac intestinal epithelium.

OBJECTIVE

Enterocyte lactase expression is a useful marker of gluten toxicity. In this study, the technique of flow cytometry was evaluated to quantify lactase expression in coeliac disease (CD).

METHODS

Duodenal enterocyte suspensions were obtained from 23 patients with CD, four patients with dermatitis herpetiformis (DH), and 33 control subjects. The percentage of enterocytes that reacted with anti-lactase monoclonal antibody was determined by flow cytometry. In some subjects, organ culture of duodenal biopsies in the presence of various stimuli (including gluten fractions) was performed before enterocyte analysis.

RESULTS

This study demonstrated that lactase expression can be readily investigated semi-quantitatively using flow cytometry. Moreover, the level of expression correlated with the extent of mucosal damage in gluten-sensitive individuals. However, in organ culture experiments, lactase expression did not change in the presence of gluten or after marked T-cell activation for 48 h.

CONCLUSIONS

Measurement of enterocyte lactase expression by flow cytometry is a useful adjunctive test in the diagnosis and monitoring of gluten-sensitive enteropathy. However, lactase expression is not a suitable marker of gluten-induced toxicity in organ culture.