This study was designed to establish whether deamidated gliadin peptide antibodies (DGP-AGA) could improve the serologic workup for celiac disease (CD).
The best serologic approach for CD screening is currently based on the combined detection of tissue transglutaminase (tTGA), endomysial (EmA), and gliadin antibodies (AGA).
One hundred forty-four consecutive patients with gastrointestinal and extraintestinal signs suggestive for CD were investigated using serologic tests, that is, IgG and IgA DGP-AGA, IgA tTGA, IgA EmA, and duodenal biopsy.
Forty-eight out of 144 patients (33%) had CD with different severity of villous atrophy. IgA tTGA showed 93.7% sensitivity compared with 91.6% for IgA EmA, 84.3% for IgA DGP-AGA, and 82.3% for IgG DGP-AGA. Of the 3 cases negative for IgA tTGA, IgA EmA, and IgA DGP-AGA, 2 had total IgA deficiency, although both were positive for IgG DGP-AGA. IgG DGP-AGA showed a very high specificity for CD (98.9%), not only superior to IgA DGP-AGA (79.8%), but also to IgA tTGA (96.6%) and very close to IgA EmA (100%).
Our prospective study shows that the combined search for IgA tTGA and IgG DGP-AGA provides the best diagnostic accuracy for CD, allowing the identification of all CD cases---except one---with a very high specificity. The serologic workup for CD screening could be significantly improved by the routine introduction of IgG DGP-AGA together with IgA tTGA, thus reducing the number of tests and with an obvious advantage in terms of cost-efficacy.
Department of Clinical Medicine, University of Bologna, Bologna, Italy
Grant Support: Italian Ministry of University and Research (COFIN Projects to R.De.G.), and R.F.O. funds from the University of Bologna (to R.De.G.). R.De.G. is a recipient of a grant from the “Fondazione Del Monte di Bologna e Ravenna” and “Fondazione Cassa di Risparmio di Bologna” (Bologna, Italy).
Financial Disclosure: None to disclose.
Reprints: Umberto Volta, MD, Department of Clinical Medicine, Building 11, St. Orsola-Malpighi Hospital, Via Massarenti 9, 40138–Bologna, Italy (e-mail: firstname.lastname@example.org).
Received for publication July 3, 2009
accepted September 24, 2009
Conflicts: No conflict of interest exists.
The Authors wish to thank Mrs Susie Phillips for editing the manuscript.