Aim: Until now IgA-EmA and IgA-AGA antibodies have been considered to be specific and sensitive markers of celiac disease. Anew antibody, the tissue transglutaminase (IgA-tTG), antibody has recently been identified, which is believed to be if not a better marker then a more practical one in screening for celiac disease, especially in large populations. To evaluate the usefulness of the IgA-tTG antibody in the diagnosis and screening of celiac disease and to determine the relationship between this antibody and other better known and over-used antibodies, antigliadin (IgA-AGA) and antiendomysial (IgA-EmA).
Patients and methods: The study was performed in 115 children divided into three groups: 31 patients diagnosed with the celiac disease, according to the ESPGAN criteria; 21 patients with celiac disease following a gluten free diet, and 63 considered as control group. Two enzyme linked immunoabsorbent assays (ELISA) were used to detect AGA and tTG antibodies, respectively. EmA antibodies were determined by using an indirect immunofluorescence technique with commercial sections of distal monkey oesophagus as antigen.
Results: In the 115 patients taken as a whole, the tTG antibody showed 91% agreement with the EmA antibody and 85% agreement with the AGA antibody. In the celiac group, agreement was 84% and 61% respectively. Sensitivity of the tTG antibody was 83% compared with 94% for EmA and 74% for AGA. Specificity was similar in all three tests.
Conclusions: The ELISA test for tTG correlates well with the traditional AGA and EmA tests and could be used as a new test for celiac disease. The procedure is simple and shows high specificity and sensitivity compared with classical EmA and AGA tests and does not involve subjective scoring. It is cheap and very well suited for large scale screening for celiac disease.