Comparison of a tissue transglutaminase ELISA with the endomysium antibodytest in the diagnosis of gluten-sensitive enteropathy

Background: Tissue transglutaminase (tTG) has recently been found to be the major if not the only autoantigen of gluten-sensitive enteropathy (GSE). Objectives: To further determine the significance of this finding for diagn ostic (screening) and follow-up purposes, we performed tTG-based ELISAs, an d compared the results to the endomysium antibody test (EMA). Patients: We examined 120 serum samples from patients with celiac disease ( CD) including 72 on a gluten-free diet (GFD) and eleven on a gluten challen ge, 47 with dermatitis herpetiformis (DH) including 16 on a GFD and one on a gluten challenge, 96 with non-CD gastrointestinal diseases, and 117 with others; i.e. 380 serum samples altogether. Follow-up sera from 13 patients were included. Methods: Results of an ELISA with guinea pig liver tTG were compared with t he EMA test using mon key esophagus. Inhibition of endomysial staining was performed with sera positive on the EMA test but negative with the guinea p ig tTG ELISA. Results: The specificity and sensitivity of the tTG ELISA are high (98.6% a nd 92.5%). The serum IgA antibody titers against tTG decrease after introdu ction of a GFD. In one case, endomysial staining could not be inhibited. Conclusions: Our results show that the guinea pig tTG ELISA is suitable for use as a simple diagnostic, screening and follow-up method for GSE. Furthe r studies are necessary to identify possible additional minor antigens in G SE.