A reliable screening procedure for coeliac disease in clinical practice

Background: The main autoantigen recognized by the sera of patients with coeliac disease (CD) is tissue transglutaminase (tTG). A human-recombinant form of tTG was used to develop an ELISA to measure anti-tTG serum antibodies for the diagnosis of CD. Preliminary retrospective reports suggest that the human tTG-based ELISA could identify coeliac patients missed by the IgA-anti-endomysium antibody test (AEA). Whether the human recombinant tTG ELISA is sufficiently accurate to become the main diagnostic CD tool in everyday clinical practice is unknown. The objective was to determine, in a prospective study, the sensitivity and specificity of an ELISA test based on the use of human tTG compared with AEA, to analyse the discordant cases for HLA DQ2-8 and for clinical and intestinal biopsy characteristics. Methods: 1106 patients referred to a gastrointestinal outpatient clinic for symptoms attributable to CD, 52 first-degree relatives of CD patients and 200 healthy controls were tested for both anti-human tTG and AEA antibodies. Results: Out of 1158 subjects, 146 were tested positive for anti-tTG antibodies and 140 were biopsy-proven coeliacs. The AEA test identified 126/1158 coeliacs who also tested positive for anti-tTG antibodies. The 14 patients missed by the AEA test carried the typical HLA-DQ for CD; they had normal levels of total serum IgA and had milder pathology than those with both anti-tTG and AEA positivity (P < 0001). Conclusions: These results prove that human tTG-based ELISA is an excellent diagnostic tool for CD, for mass screening by both the specialist and the general clinic.