Antibodies against deamidated gliadin peptides in early-stage celiac disease

The widely used serum endomysial (EmA) and transglutaminase 2 (TG2-ab) antibodies predict forthcoming villous damage and celiac disease when the small-bowel mucosa structure is still normal. However, these autoantibodies may remain negative in this early stage of the disease. We hypothesized that the antibodies against deamidated gliadin peptides (DGP-AGA) might appear before the other antibodies and would thus be useful in the diagnosis and follow-up of patients with early-stage celiac disease.

Serum DGP-AGA, TG2-ab, and EmA were measured at baseline and after 1 year on a gluten-free diet in 42 adults proven to have early-stage celiac disease despite normal small-bowel mucosal morphology (Marsh I-II), and in 20 celiac subjects evincing villous atrophy (Marsh III). Thirty-nine subjects with no signs of celiac disease served as nonceliac controls.

Sensitivity to detect early-stage celiac disease was 79% for DGP-AGA, 64% for TG2-ab, and 81% for EmA. Specificities were 95%, 100%, and 100%, respectively. The corresponding efficiencies of the tests were 89% for DGP-AGA, 81% for TG2-ab, and 91% for EmA. All 3 antibodies were significantly decreased on a gluten-free diet.

This study showed that the sensitivity of DGP-AGA was superior to TG2-ab and comparable to EmA in celiac patients having early-stage celiac disease with normal villous morphology. On the basis of these results, DGP-AGA would seem to offer a promising new method for case-finding and follow-up in this entity.