: Tissue Transglutaminase IgA Antibody, Immunoassay (Serum)
: This test measures IgA-class antibodies against tissue transglutaminase, an enzyme involved in the immune response associated with celiac disease. It is commonly used as a blood screening test to help detect celiac disease.
[": A positive tTG-IgA result suggests an immune reaction to gluten and is typically followed by confirmatory testing."]
Key facts at a glance
- LOINC
- 17745-1
- Short code
- TMA IgM Qn
- Synonyms
- TMA IgM Qn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
: What This Test Measures
: The test detects immunoglobulin A (IgA) antibodies that target tissue transglutaminase, a protein found in various tissues. Elevated levels of these antibodies can indicate an autoimmune response to gluten, the protein found in wheat, barley, and rye.
: Why It Is Ordered
: Healthcare providers often order this test when a person has symptoms suggesting celiac disease, such as digestive problems, unexplained weight loss, fatigue, or anemia. It may also be used to screen people at higher risk, such as those with a family history of celiac disease or related autoimmune conditions.
: How the Sample Is Collected
: A small blood sample is drawn from a vein, usually in the arm. No special preparation is typically required, though you should follow any instructions from your provider.
: Understanding the Results
: Results are usually reported as a numeric value with a reference range specific to the laboratory that performed the test. Whether a result is considered positive depends on that lab's cutoff. A positive or elevated result does not by itself confirm celiac disease and is generally interpreted alongside symptoms and other tests ordered by your provider.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
: tTG-IgA is a key serologic marker for celiac disease. Because IgA deficiency can cause false-negative results, providers often order a total IgA level at the same time. A positive result usually leads to referral for further evaluation, which may include additional antibody tests and, in many cases, a small bowel biopsy to confirm the diagnosis. Results should always be interpreted by a qualified healthcare professional in the context of the full clinical picture.
Short name
: tTG-IgA
Frequently asked questions
: Do I need to fast before this test?
: Can this test tell me if I have celiac disease on its own?
: Should I stop eating gluten before testing?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy