OVERVIEW
What is a celiac disease?
It is an autoimmune disorder where body produces inappropriate immune response against gluten i.e. a protein found in wheat, & related dietary proteins in barley and rye. Celiac disease & few other gluten-sensitive diseases can be diagnosed & monitored via antibody tests which look for autoantibodies in the blood. Various antibodies are measured for its amount found in blood that help in differential diagnosis of celiac disease. These antibody tests include tTG IgA, IgA, tTG IgG, & DGP antibodies IgA/IgG.
What is anti-gliadin IgG (anti-DGP) lab test?
This test is used for quantitative determination i.e. measures amount of IgG antibodies released against DGP (deaminated gliadin peptide epitopes) in human blood (plasma or serum). Gliadin is one of the main proteins found in gluten which is deaminated by tTG (tissue transglutaminase) and release DGP fragments. Then against this DGP, antibodies are initiated as an extensive immune response.
Why is anti-gliadin IgG (anti-DGP) lab test done?
The test is done:
• To detect antigliadin antibodies & help in diagnosis and monitoring of gluten-sensitive conditions like celiac disease or dermatitis herpetiformis (chronic intensely itchy blistering skin)
• It helps in detection of gliadin involvement in medical condition
• Used in celiac disease suspected patients, symptomatic patients, atypical symptom patients, & those at increased risk of disease
• When patient suspects celiac disease but is negative for anti-tTG which especially occurs in children younger than 2 years
• Positive anti-DGP test is used to monitor celiac disease
• In patients with IgA deficiency, healthcare professionals order DGP-IgG test
• Used in people with negative test for EMA antibodies (anti-endomysial antibodies)
• IgG antibody is less specific for celiac disease, but it tends to be useful in diagnosing autoimmune conditions in patients who are IgA deficient.