This assay is useful in evaluating patients with Celiac disease including those with compatible symptoms, atypical symptoms and individuals at increased risk such as those positive for HLA DA2/DQ8. Ingestion of Gliadin peptides contained in wheat, rye and barley induce immune mediated inflammation of small intestine in genetically susceptible individuals with Gluten sensitive enteropathy / Celiac disease. This disease is more common in first and second degree relatives of patients with Celiac disease, individuals with Down Syndrome, Turner syndrome, Williams syndrome, Selective IgA deficiency and Autoimmune disorders. Usage of Deamidated molecule increases the specificity and sensitivity of the assay. It is also used as a screeing test for Dermatitis herpetiformis. This assay also monitors adherence to gluten free diet. Test sensitivity increases from 91.5% for tTG IgA antibody alone to 98.5 % when both IgA and IgG antibodies are tested together.