Description
The Tissue Transglutaminase (tTG) IgA and IgG blood tests measure antibodies associated with celiac disease, an autoimmune condition in which gluten triggers an immune response that can damage the lining of the small intestine.
What Does This Test Evaluate?
This testing measures:
- tTG IgA antibodies – generally the preferred initial antibody test for celiac disease
- tTG IgG antibodies – may provide additional information, particularly in individuals with IgA deficiency
Why Consider tTG Testing?
Celiac disease can cause a wide range of gastrointestinal and non-gastrointestinal symptoms, including:
- Abdominal discomfort or bloating
- Chronic diarrhea or constipation
- Unexplained iron-deficiency anemia
- Fatigue
- Unexplained weight loss
- Nutrient deficiencies
- Bone loss
- Certain chronic skin conditions
Some individuals with celiac disease have few or no gastrointestinal symptoms.
For the most accurate antibody testing, individuals should generally be consuming gluten regularly before testing. Starting a gluten-free diet before testing can lower antibody levels and potentially produce a false-negative result.
A Total IgA level is often measured along with tTG IgA to identify IgA deficiency, which can affect interpretation of the tTG IgA result.
Positive antibody testing does not by itself establish a definitive diagnosis of celiac disease. Additional evaluation may be recommended.
Specimen: Blood draw Preparation: No fasting typically required; continued gluten consumption is generally recommended before testing
