TTG IgA test is done to detect the Transglutaminase IgA antibodies in the blood. It is done on the patient who is suffering from the clinical symptoms of celiac disease. If you are someone with the compatible clinical symptoms, patients with atypical symptoms, and individuals at increased risk (family history, previous diagnosis with the associated disorder, positivity for HLA DQ2 and/or DQ8), then this test is for you.