Prevalence and Clinical Significance of Gliadin Antibodies in Healthy Children and Adults

Abstract

Coeliac disease (CD) is associated with the presence of gliadin antibodies (GA) (IgG and IgA), often used as a screening test for CD. Using a modified micro-enzyme-linked immunosorbent assay for GA, we studied the prevalence of GA in three healthy groups: children (mean age, 12 years), adult blood donors (mean age, 38 years), and healthy women (mean age, 57 years). We also studied the clinical characteristics of the blood donors. On the basis of findings in 27 untreated CD patients, cut-off levels of IgG and IgA antibody titres were chosen to yield a test with relatively low sensitivity (56%) but high specificity (100%). Analysis of IgM antibodies did not improve the sensitivity. Of the 384 12-year-old children, both IgG and IgA GA positivity was found in 15 (3.91%), a rate significantly greater than that in the blood donors (22 of 1537, 1.43%; p < 0.001) or in the middle-aged women (11 of 944, 1.17%; p < 0.0001). Of the 22 GA-positive healthy blood donors, 13 underwent small-bowel biopsy, but only 1 of the specimens manifested histologic changes compatible with CD. The other 12 had normal specimens, including a normal intraepithelial lymphocyte count. The estimated frequency of CD among the blood donors was thus 1 of 1500, a figure consistent with those previously published. We conclude that GA occur frequently in the Swedish population but that their prevalence decreases with increasing age. As a screening test for CD in healthy individuals, the GA titre is of poor predictive value.

Prevalence of IgA-Antigliadin Antibodies and IgA-Antiendomysium Antibodies Related to Celiac Disease in Children With Down Syndrome

“…The frequency of AGA-positivity (37%) is high, not only compared with the findings in our population-based screening study, 12 but also with those of recent investigations of larger DS series, which yielded prevalences of 10% to 26%. 5,17,18 In one study, 10% (8/78) of the patients were AGA-positive, two of them having CD.…”

“…In children Ͻ5 years of age, the sensitivity was 92% and the specificity 84%, based on findings in 85 patients with CD and 144 patients without CD. The AGA data for the control group sera have been published separately 12 and were obtained with an in-house enzyme-linked immunosorbent assay using the same gliadin type of antigen as for the Pharmacia assay. The cutoff level of the in-house method was set to yield a sensitivity of 56% and a specificity of 100%, ie, values similar to those obtained with the cutoff adopted by us for the Pharmacia assay.…”

Frequent Occurrence of Non-Specific Gliadin Antibodies in Chronic Liver Disease Endomysial but Not Gliadin Antibodies Predict Coeliac Disease in Patients with Chronic Liver Disease

“…Notably, of these five patients, four had cryptogenic liver disease, and the fifth had PBC (8). Of 19 patients with both IgA and IgG GAS in this liver disease series, 5 (26%) had CD, and thus the predictive value of a positive GA test with regard to C D was higher than that found in a control group of healthy blood donors, of whom only 4.5% (1 of 22, 13 biopsied) of those with IgA + IgG GA manifested villous atrophy (9). Sequential testing for GAS and then for endomysial antibodies (EMAs) has been advocated during recent years (10).…”

“…Healthy blood donors, Comparisons were made with a group of 1,537 healthy blood donors (420 women), mean age 38 years (range, 19-70) previously described (9). The blood donor samples were analysed consecutively.…”

“…using a test with a specificity high enough to identify those with CD. If either IgA GA positivity or IgG GA positivity is considered to indicate the presence of CD, the sensitivity of our procedure in patients with gastrointestinal symptoms is 920/, and the specificity 86% (9). The IgA GA test used alone with the same cut-off values would yield a sensitivity of 78% and ii specificity of 92%.…”