Point-of-care testing for coeliac disease: primary care diagnostic technology update

Abstract

#### Clinical Question In primary care patients with suspected coeliac disease, what is the accuracy and utility of point-of-care (POC) testing for coeliac disease compared to standard practice? Coeliac disease is a malabsorption syndrome precipitated by gluten ingestion, and characterised by inflammation of the small intestine. Serological tests for IgA anti-tissue transglutaminase antibody (tTGA) and anti-endomysial antibody (EMA) have high sensitivity and specificity for coeliac disease.1,2 In patients with IgA deficiency, the IgG class of the tTGA and EMA tests are recommended. Anti-gliadin antibodies are no longer used for the detection of coeliac disease, except in children younger than 18 months.2 Conventional serological tests are performed in central laboratories, whereas the point-of-care (POC) test can be performed in practice or at home. Both the POC and conventional serological tests require patients to be on a normal gluten-containing diet at the time of testing, since IgA-tTGA titres diminish on a gluten-free diet. Two POC devices available on the market were identified. ### Biocard Coeliac Test Kit (Ani Biotech, Finland; UK Distributor: BHR Pharmaceuticals Ltd) There are two versions of the test, a home test and a professional test; a ‘total IgA measuring system’ is included in the professional kit. The Biocard requires a drop of whole blood (finger-prick) and provides results within 10 minutes. Anti-tTG IgA antibodies bind to antigen in the test strip to form a visible line. A positive test result shows two lines, while only one line appears if the test is negative. If there is no line, IgA deficiency should be suspected. ### Stick CD1 and CD2 (Operon SA, Zaragoza, Spain) Both are one-step tests detecting IgA, IgG, and IgM antibodies against human tTG; and the CD2 test also detects anti-gliadin antibodies. The tests use serum instead of whole blood, which limits …