IgG, IgA and IgE gliadin antibody determinations as screening test for untreated coeliac disease in children, a multicentre study.

The diagnostic value of gliadin IgG, IgA and IgE antibody (AB) determinations using the fluorescent immunosorbent test was examined in 586 children with malabsorptive disorders and/or failure to thrive. All patients underwent jejunal biopsy and were on a gluten-containing diet. IgG AB were found in all patients (331/331) with untreated coeliac disease (CD) in our study, but IgA AB in only 295/331 (89%). Therefore a screening test based only on IgA AB determinations is not recommended. By contrast, 203 (80%) of 255 children with other malabsorptive disorders had no gliadin AB, 43 (16.5%) had only IgG AB and only 9 (3.5%) had IgG and IgA AB. IgE AB proved to be of no additional value as a diagnostic tool because they were found in a quarter of the children without CD. Statistical evaluation of combined IgG and IgA AB determination showed at least 96% sensitivity and a specificity of 97%. The subjective ("Bayesian") probability that an actual patient with a given AB test result has CD, is considered: a patient very probably has CD in the case of positive IgG and IgA AB, and no CD in the case of a negative AB result. In the case of negative IgA AB but positive IgG AB the physician's judgement ("prior probability") influences the ("posterior") probability of CD for an actual patient. In contrast to IgG AB, IgA AB decline rapidly after the introduction of a gluten-free diet and may be used for diet control after diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)