Antitransglutaminase enzyme-linked immune-adsorbed assay in coeliac disease diagnosis: evaluation of a diagnostic algorithm.

BACKGROUND: Tissue transglutaminase is the major autoantigen recognized in the sera of coeliac patients. An enzyme-linked immune-adsorbed assay based on tissue transglutaminase was recently used to measure serum tissue transglutaminase immunoglobulins A for coeliac disease diagnosis. OBJECTIVES: To determine the sensitivity, the specificity, the positive and negative predictive values of an immunoenzymatic assay based on guinea pig tissue transglutaminase, to compare antititransglutaminase immunoenzymatic assay to the antiendomysium immunofluorescent assay, and to define a cost-effective sequence to execute serum antibody determination in coeliac patients. METHODS: We assessed for coeliac disease antibodies 91 pediatric patients with symptoms suggestive of coeliac disease, and 23 patients with coeliac disease on a gluten-free diet as controls. RESULTS: Antitransglutaminase immunoglobulins A showed 93.1% sensitivity, 93.6% specificity, 87.1% positive and 96.7% negative predictive values. Antitransglutaminase immunoglobulins A were significantly higher in antiendomysium positive subjects. Correlation between antitransglutaminase immunoglobulins A and antigliadin immunoglobulins A was not significant. DISCUSSION: Our results show that antitransglutaminase immunoenzymatic assay represents a cost-effective strategy for patients' serological evaluation and it could substitute EMA determination, which could be considered a second level evaluation.