Introduction

Coeliac disease (CD) is a chronic autoimmune disorder of the small intestine induced in genetically susceptible individuals by the ingestion of gluten, the major storage protein of wheat, rye and barley.1 It has been estimated that overall prevalence of CD in the general population is as high as 1/160 or 0.62%.2 The current diagnostic algorithm for CD includes initial serological screening test, followed by a confirmatory small intestinal biopsy showing the autoimmune insult typical of CD.3 4 In following such an approach, serological screening is primarily used to identify those individuals in need of a diagnostic endoscopic biopsy.3 5

The most sensitive and specific serological tests for the diagnosis of CD are based on the detection of immunoglobulin A (IgA) antibodies against human tissue transglutaminase (tTGA) enzyme and connective tissue elements covering individual smooth muscle fibres, endomysium antibodies (EMA).1 3 6

Detection of tTGA is currently proposed as the first choice serological test in screening for CD.3 4 This recommendation has been based on high sensitivity (up to 98%) and high specificity (around 96%) reported for the tTGA assay.5 7,–,9 The tTGA test also demonstrates a remarkable negative predictive value approaching 100% and, therefore, represents an excellent tool in excluding CD in both high and low risk groups.8 9 In contrast, positive predictive value of the tTGA test is rather poor with values between 28.6% and 60.2% being reported in several studies.10 Performance of the alternative assay detecting EMA as a screening tool for CD is characterised by extremely high …