Goals: This study was designed to establish whether deamidated gliadin peptide antibodies (DGP-AGA) could improve the serologic workup for celiac disease (CD).
Background: The best serologic approach for CD screening is currently based on the combined detection of tissue transglutaminase (tTGA), endomysial (EmA), and gliadin antibodies (AGA).
Study: 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.
Results: 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%).
Conclusions: 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.