Gliadin Antibodies (IgG & IgA) (deamidated) Blood Tests

The Gliadin Antibodies (IgG & IgA) (deamidated) test is a diagnostic tool used primarily to assist in the detection and management of coeliac disease. Gliadin is a component of gluten, found in wheat and other grains. The test specifically looks for antibodies against deamidated gliadin peptides (DGPs), which are modified forms of gliadin that the body may react to more aggressively in people with celiac disease.

Here’s an overview of the role and importance of this test:

1. Detection of Coeliac Disease: Coeliac disease is an autoimmune disorder where ingestion of gluten leads to damage in the small intestine. The immune system of individuals with celiac disease produces antibodies against gliadin, and these antibodies can be detected in the blood. The deamidated forms of gliadin peptides are particularly immunoreactive, making them useful markers for coeliac disease.
2. Enhanced Specificity and Sensitivity: Traditional tests looked for antibodies against native gliadin, but these could sometimes result in false positives, such as in individuals with other conditions like wheat allergy or non-coeliac gluten sensitivity. The deamidated gliadin peptides test is more specific to coeliac disease, reducing the likelihood of false-positive results.
3. Assessment of Both IgG and IgA: Testing for both IgG and IgA antibodies increases the diagnostic accuracy. Some individuals with coeliac disease may have selective IgA deficiency, which could lead to a false negative if only IgA antibodies were measured. Including IgG ensures better coverage and accuracy.
4. Monitoring Dietary Compliance: Once a diagnosis of coeliac disease is confirmed, periodic testing of DGP antibodies can help monitor the patient’s compliance with a gluten-free diet, as the antibody levels should decrease when gluten is eliminated from the diet.
5. Early Diagnosis in At-Risk Populations: This test can be particularly useful for screening individuals who are at risk of coeliac disease but may not yet show symptoms, such as first-degree relatives of people with celiac disease, or those with other autoimmune disorders.

The Gliadin Antibodies (IgG & IgA) (deamidated) test is a critical component of the diagnostic process for coeliac disease and is used by healthcare providers to both diagnose the disease and monitor the effectiveness of treatment through dietary changes.