Usefulness of deamidated gliadin peptide antibodies in diagnosing coeliac disease in children younger than 3 years old.

Abstract

The standard serological test to screen for coeliac disease (CD) is tissue transglutaminase (tTG) but some experts recommend including deamidated gliadin peptide (DGP) antibodies for children younger than 3 years old. This study evaluated the utility of DGP-immunoglobulin A (IgA) and DGP-immunoglobulin G (IgG) serologies when screening children younger than 3 years old for CD. A retrospective chart review was conducted including children 3 years old and under, who had DGP and/or tTG serologies along with duodenal biopsies during their initial diagnostic evaluation. Serology results were compared to the gold-standard histopathology by χ2 to determine the significance of including DGP-IgG/IgA serologies when screening for CD in this age group. We identified 478 patients, 52 who were younger than 3 years old, 43 of whom met inclusion criteria. The positive predictive value (PPV) of the DGP-IgA test was 91.7% whereas, DGP-IgG was 77.8%. When DGP serology was examined in conjunction with tTG-IgA, the PPV with DGP-IgA was 90.9% and with DGP-IgG was 87.5%. In isolation, DGP-IgA provides a high PPV and specificity for CD in children younger than 3 years old, whereas DGP-IgG had a much lower PPV in this age group. When used alone or in conjunction with tTG-IgA, the DGP-IgA test results in a high PPV of 91.7 and 90.9%, respectively. Based on our study, we recommend obtaining both the DGP-IgA and the tTG-IgA serology when screening infants and children younger than 3 years old for coeliac disease.