Screening and Monitoring Coeliac Disease: Multicentre Trial of a New Serum Antibody Test Kit

Abstract

A multicentre trial was conducted to evaluate a new test for anti-gliadin antibodies (AGA) in serum (Coeliac Screening Kit, CSK, Medical Innovations Limited, Artarmon, NSW, Australia). The test showed excellent reproducibility for both anti-gliadin IgA and IgG detection. The average intraassay coefficient of variation (CV) was 3.0% for IgA and 2.4% for IgG (n=6), while the average interassay CV was 6.4% for IgA and 4.3% for IgG (n=3). By defining a positive test as both IgA and IgG elevated, a sensitivity of 93% in untreated coeliacs (n=75) was observed. The corresponding specificities in healthy adults (n=l 30) and healthy children (n=77) were >99% and 100% respectively, while in patients with other gastrointestinal disorders (disease controls) the specificity was 94% (n= 129). The test was also useful in monitoring patients, with anti-gliadin IgA and IgG falling for up to a year after commencing a gluten-free diet (GFD) (12 adults). In some patients however, antibody levels did not reach the normal cutpoint after many months on a GFD, which may reflect the patients’ poor adherence to their gluten free diet. The test was superior to the Pharmacia anti-gliadin ELISA, and should be useful as an aid to the diagnosis of coeliac disease, as well as in the follow-up of treated patients. © 1994, Asfra B.V.