Coeliac Disease : Serological tests

Serological testing methods for celiac disease play a crucial role in the initial screening and diagnosis of this autoimmune condition. These tests look for specific antibodies in the blood that are typically present when an individual reacts to gluten, a protein found in wheat, barley, and rye. The presence of these antibodies suggests an immune response triggered by gluten ingestion, characteristic of celiac disease.

The first step in serological testing usually involves measuring antibodies such as Immunoglobulin A (IgA) tissue transglutaminase (tTGA), which has high sensitivity and specificity for celiac disease. Because some individuals may have an IgA deficiency, which could skew the results of IgA-based tests, total IgA levels are also checked to ensure accurate interpretation of the tTGA test.

For cases where the tTGA test is inconclusive or when an IgA deficiency is present, second-line tests such as IgG deamidated gliadin peptide (DGP), IgG tTGA, and IgA endomysial antibody (EMA) tests are used. These tests provide alternative pathways for diagnosis, ensuring that celiac disease can be identified even in patients with complicating factors that might otherwise mask the condition.

It's important for patients undergoing serological testing for celiac disease to continue consuming gluten up to the test date....