Celiac disease is a chronic immune-mediated small intestine disease that occurs in genetically predisposed individuals in response to gluten ingestion. The disease can present with numerous symptoms (from the digestive system or extraintestinal symptoms), but it can also exist without symptoms. It is effectively treated with a gluten-free diet. Celiac disease is characterized by elevated levels of antibodies in the blood. In diagnostics and screening, antibodies to tissue transglutaminase of the immunoglobulin A class (anti-tTG) are most commonly used. These antibodies are used because of their optimal ratio of specificity, sensitivity, simplicity, and cost. Antibodies to tissue transglutaminase usually normalize within 18-24 months after eliminating gluten from the diet. Despite many tests, it is still not clear at what rate anti-tTG recovers after the introduction of a gluten-free diet, nor all the factors that affect this process. Anti-tTG normalizes more slowly in patients who initially have a high antibody titer (over 10x ULN) compared to those who have a low titer (below 10x ULN). A high level of anti-tTG is associated with a greater number of intestinal symptoms, while it is inversely proportional to the number of extraintestinal symptoms. The presence of other autoimmune diseases, such as type 1 diabetes, can slow recovery. Recovery is also slower in girls and in people who are not of European origin, and in the case of persistently high values, it is primarily necessary to exclude incorrect implementation of a gluten-free diet. Considering the prevalence of celiac disease and the widespread use of the anti-tTG IgA test, it is important to understand its role in diagnostics, as well as in patient monitoring and the characteristics of its dynamics, so as not to miss out on making the correct diagnosis, recognizing treatment irregularities, and detecting complications. In conclusion, anti-tTG represents an effective and appropriate test for the diagnosis and monitoring of celiac disease, but it is necessary to be aware of its scope and limitation.