Anti tissue transglutaminase IgA analysis (Anti Tissue Transglutaminase IgA, Serum) is a laboratory test used to diagnose celiac disease, a condition that affects the digestive system as a result of an immune reaction to gluten. The test measures the level of antibodies in the blood, helping to determine whether there is an abnormal reaction to gluten. This analysis is considered an important tool for diagnosing food sensitivities and guiding appropriate treatment.