TISSUE TRANSGLUTAMINASE IGA, SERUM

Tissue Transglutaminase IgA (tTG-IgA), Serum

What it is

The Tissue Transglutaminase IgA (tTG-IgA) serum test measures antibodies directed against the enzyme tissue transglutaminase. These antibodies are strongly associated with celiac disease, an autoimmune disorder triggered by gluten ingestion. The tTG-IgA test is considered the most sensitive and specific blood test for detecting celiac disease.

Uses

This test is primarily used to help diagnose celiac disease and to monitor the effectiveness of a gluten-free diet in individuals already diagnosed. It is often ordered alongside total serum IgA to rule out IgA deficiency, which can affect accuracy. In children and adults with suspected gluten sensitivity, this is the first-line serological test.

Symptoms That May Lead to the Test

Doctors may recommend the tTG-IgA test if you experience chronic diarrhea, bloating, abdominal pain, fatigue, anemia, osteoporosis, unexplained weight loss, delayed growth (in children), or a family history of celiac disease. It may also be used in autoimmune patients at higher risk for gluten intolerance.

Abnormal Results

Positive tTG-IgA: Strongly suggests celiac disease, especially when supported by symptoms and confirmed with an intestinal biopsy. Levels usually decrease after following a strict gluten-free diet.

Negative tTG-IgA: Suggests a lower likelihood of celiac disease. However, false negatives may occur in patients with IgA deficiency or those already on a gluten-free diet before testing.

Risks

The test requires a standard blood draw, with minimal risks such as mild pain, bruising, or temporary dizziness. There are no long-term risks associated with the procedure.