Gliadin Deamidated Antibody IgG

What the laboratory says this test is for

Celiac disease is characterized by the presence of Transglutaminase, Gliadin, and Reticulin Antibodies. Such patients display a hypersensitivity to gluten (wheat) in their diet. The antibody is undetectable when patients with hypersensitivity are placed on gluten-free diets. Antibody IgA is more specific and IgG is more sensitive to Celiac disease.

What the laboratory says this test is for

This panel is used to assist in the diagnosis of celiac disease (CD) in children ≤5 years old. Background: CD is caused by an immune response to gluten in genetically sensitive individuals. Diagnosis begins with serologic testing and is confirmed by biopsy. This panel tests all specimens for tissue transglutaminase (tTG) IgA and gliadin (deamidated) IgA and IgG. Although tTG IgA is generally preferred as a single serological test for CD, it may have reduced sensitivity in young children; including DGP IgA and IgG alongside tTG IgA may increase sensitivity for CD. Specimens positive for tTG IgA are tested for endomysial antibody (IgA), which may increase specificity for CD. This panel also evaluates all specimens for total IgA. A total IgA level below the reference range is suggestive of IgA deficiency and reflexes to tTG IgG, which is generally less sensitive than tTG IgA for CD but is useful in the context of IgA deficiency.

What the laboratory says this test is for

Detection of antibodies to gliadin, one of the major protein components of gluten, is a sensitive assay useful in diagnosing celiac disease. However, gliadin antibodies may be found in individuals without celiac disease; thus gliadin antibody assays are less specific than assays measuring antibodies to endomysium and transglutaminase. Recent work has revealed that gliadin-reactive antibodies from celiac patients bind to a very limited number of specific epitopes on the gliadin molecule. Further, deamidation of gliadin results in enhanced binding of gliadin antibodies. Based on this information, assays using deamidated gliadin peptides bearing the celiac-specific epitopes have much higher diagnostic accuracy for celiac disease when compared to standard gliadin antibody assays.