The presence of anti-endomysial antibodies and the level of anti-tissue transglutaminases can be used to diagnose adult coeliac disease without duodenal biopsy

BackgroundThe new ESPGHAN guidelines for diagnosis of paediatric coeliac disease suggest to avoid biopsy in genetically pre-disposed and symptomatic individuals with positive anti-endomysial antibodies (EMA) and anti-tissue transglutaminases (a-tTG). However, duodenal biopsy remains the gold standard in adult coeliac disease. AimsTo establish the cut-off values of a-tTG, which would: predict the presence of duodenal histology (Marsh 2) diagnostic for coeliac disease; and predict the presence of villous atrophy (Marsh 3) in adults. MethodsWe performed an observational prospective study including all consecutive adult patients with suspected coeliac disease. All subjects were tested for EMA and a-tTG. Coeliac disease diagnosis was made in presence of Marsh 2, a-tTG >7U/mL and positive EMA. A ROC curve was constructed to establish the best specificity cut-off of a-tTG levels, which would predict the presence of Marsh 2 and Marsh 3 at histology. ResultsThe study included 310 patients with positive antibodies. Histology showed Marsh 1 in 8.7%, Marsh 2 in 3.5%, Marsh 3 in 87.7%. The best cut-off value of a-tTG for predicting Marsh 2 was 45U/mL (sensitivity 70%; specificity 100%; PPV 100%; NPV 24.1%); the best cut-off for predicting villous atrophy was 62.4U/mL (sensitivity 69%, specificity 100%; PPV 100%; NPV 31%). ConclusionsThe diagnosis of coeliac disease can be reached without histology in adult patients with positive EMA and a-tTG levels >45U/mL. An a-tTG level >62.4 was diagnostic for villous atrophy. These results could contribute to improving the diagnosis of coeliac disease by allowing for a significant reduction in diagnosis-related costs.