Tissue Transglutaminase (tTG) Antibodies IgA & IgG Biomarker Testing
It checks immune antibodies linked to celiac disease and gluten-related intestinal injury, with convenient ordering and clear results through Vitals Vault.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
The Tissue Transglutaminase (tTG) Antibodies IgA & IgG test looks for immune proteins (antibodies) that your body may produce when gluten triggers inflammation in the small intestine. It is one of the most commonly used blood tests to screen for celiac disease.
This test is most useful when you have symptoms that could fit celiac disease, when you have a related autoimmune condition, or when you are trying to understand unexplained nutrient deficiencies. Your result is not a diagnosis by itself, but it can guide what to do next with your clinician.
One important detail: results are easiest to interpret when you are currently eating gluten. If you have already gone gluten-free, the antibodies can fall and the test may look “normal” even if celiac disease is present.
Do I need a Tissue Transglutaminase (tTG) Antibodies IgA & IgG test?
You may want this test if you have ongoing digestive symptoms such as chronic diarrhea, bloating, abdominal pain, or unexplained weight loss. It is also reasonable when symptoms are not strictly digestive, because celiac disease can show up as fatigue, iron-deficiency anemia, low folate or B12, low vitamin D, bone loss, mouth ulcers, headaches, or a persistent itchy rash (dermatitis herpetiformis).
Testing is also commonly considered if you have a higher-risk background, even with mild or no symptoms. That includes a first-degree relative with celiac disease, type 1 diabetes, autoimmune thyroid disease, certain liver conditions, or other autoimmune patterns.
If you are already avoiding gluten, talk with your clinician before testing. Antibody levels often decrease on a gluten-free diet, so you may need a supervised “gluten challenge” for accurate screening.
This test supports clinician-directed care and follow-up planning; it is not meant for self-diagnosis or for deciding on long-term dietary restriction without confirmation.
This is a blood immunoassay performed in a CLIA-certified laboratory; results should be interpreted with your symptoms, diet, and any follow-up testing recommended by your clinician.
Lab testing
Order labs to measure Tissue Transglutaminase (tTG) Antibodies (IgG, IgA)
from $211.44 at Quest Diagnostics
About 1 week
Schedule online — results typically within a week
Clear next steps
Guidance included, with follow-up care available
HSA / FSA
Eligible for pre-tax health spending accounts
Get this test with Vitals Vault
With Vitals Vault, you can order Tissue Transglutaminase (tTG) Antibodies IgA & IgG testing without needing to coordinate a separate lab requisition visit. You complete checkout, visit a local draw site, and then review your results in one place.
If your result is positive, borderline, or confusing because you have already changed your diet, PocketMD can help you understand what the number means and what questions to bring to your clinician. If your result is negative but your symptoms persist, PocketMD can also help you think through common next steps, such as checking total IgA, deamidated gliadin peptide (DGP) antibodies, nutrient status, or other causes of similar symptoms.
Because antibody levels can change over time, especially after starting a gluten-free diet, Vitals Vault also makes it straightforward to recheck the same marker later so you can track trends and response to a plan you and your clinician choose.
- Simple ordering and a clear lab report you can share with your clinician
- PocketMD support for interpreting results and planning follow-up questions
- Easy retesting when you need to confirm changes over time
Key benefits of Tissue Transglutaminase (tTG) Antibodies testing
- Helps screen for celiac disease by detecting antibodies commonly elevated when gluten damages the small intestine.
- Supports earlier investigation of unexplained anemia, fatigue, low vitamin levels, or bone loss that can stem from malabsorption.
- Adds clarity when digestive symptoms persist and you want an objective marker to guide next steps.
- Includes both IgA and IgG antibody classes, which can be helpful when IgA-based testing may miss cases (such as IgA deficiency).
- Can be used to monitor antibody trends after starting a gluten-free diet, alongside symptom and nutrition follow-up.
- Helps you and your clinician decide whether confirmatory testing (such as endoscopy/biopsy) is worth pursuing.
- Pairs well with companion labs (total IgA, DGP, EMA, nutrient panels) to reduce false reassurance or over-interpretation.
What is Tissue Transglutaminase (tTG) Antibodies IgA & IgG?
Tissue transglutaminase (tTG) is an enzyme found in many tissues, including the lining of your small intestine. In celiac disease, gluten exposure can trigger an immune reaction that mistakenly targets tTG. Your immune system may produce antibodies against tTG, most commonly of the IgA type, and sometimes IgG.
The tTG antibody test measures how strongly your blood reacts to tTG. A higher result suggests your immune system has been activated in a way that is consistent with celiac disease, especially when you are eating gluten and when other supporting tests (like total IgA or endomysial antibody) align.
The test is a screening tool, not a stand-alone diagnosis. Some people with positive antibodies need confirmatory evaluation, and some people with symptoms may still have celiac disease even if antibodies are not elevated (for example, if they are not eating gluten, if disease is mild/patchy, or if the wrong antibody class is measured).
Why IgA and IgG both matter
Most celiac screening relies on tTG-IgA because it is highly informative in many people. However, if you have selective IgA deficiency (a condition where your body makes very little IgA), an IgA-based test can be falsely negative. Measuring tTG-IgG alongside tTG-IgA can reduce the chance of missing a signal in that situation.
What the test can and cannot tell you
A positive result increases the likelihood of celiac disease, but it does not confirm the diagnosis by itself. It also does not tell you exactly how much intestinal damage is present. A negative result lowers the likelihood, but it does not fully rule out celiac disease if you are gluten-free, if symptoms are strong, or if other risk factors are present.
What do my Tissue Transglutaminase (tTG) Antibodies IgA & IgG results mean?
Low or negative tTG antibody levels
A low (often reported as negative) tTG-IgA and tTG-IgG result usually means there is no strong antibody signal suggesting celiac disease at the time of testing. This is most reassuring if you were eating gluten regularly for several weeks before the blood draw. If you were already gluten-free or mostly gluten-free, antibodies can fall and the test may look negative even when celiac disease is present. If symptoms or risk factors remain, your clinician may add total IgA, DGP antibodies, or consider other evaluations.
In-range tTG antibody levels
Many labs report a reference range with a “negative” or “normal” zone and sometimes an “equivocal/borderline” zone. An in-range result generally aligns with no current measurable autoimmune response to tTG. If you have ongoing symptoms, the next step is often to look for other causes of similar symptoms (such as IBS, lactose intolerance, inflammatory bowel disease, thyroid disease, or chronic infection) while also confirming that the test was done under the right conditions (gluten exposure and appropriate antibody class testing).
High or positive tTG antibody levels
A high (positive) tTG antibody result suggests your immune system is reacting in a pattern commonly seen in celiac disease, especially if you are eating gluten. Higher titers generally increase suspicion, but the exact cutoffs and interpretation depend on the lab method. Your clinician may recommend confirmatory testing, often including endomysial antibody (EMA) and/or an upper endoscopy with small-bowel biopsy, before you commit to a lifelong gluten-free diet. If you have symptoms of malabsorption, follow-up may also include checking iron studies, folate, B12, vitamin D, and bone health.
Factors that influence tTG antibody results
Your gluten intake is one of the biggest drivers of the result; reducing or eliminating gluten can lower antibodies over time. IgA deficiency can make tTG-IgA misleadingly low, which is why total IgA or IgG-based testing can matter. Age, timing, and disease distribution can also affect sensitivity, and early or mild disease may not produce a strong antibody signal. Less commonly, other autoimmune or inflammatory conditions can be associated with false-positive or nonspecific elevations, so confirmation and clinical context are important.
What’s included
- TISSUE TRANSGLUTAMINASE AB, IGA
- Tissue Transglutaminase Ab, Igg
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Frequently Asked Questions
Do I need to be eating gluten before a tTG IgA/IgG test?
Yes, in most cases. If you have been gluten-free or mostly gluten-free, tTG antibodies can drop and the test may be negative even if celiac disease is present. Ask your clinician whether you need a supervised gluten challenge and how long to do it before testing.
What is the difference between tTG IgA and tTG IgG?
They are different antibody classes your immune system can produce against tissue transglutaminase. tTG-IgA is the standard screening test for many people, while tTG-IgG can be helpful when IgA is low (IgA deficiency) or when an IgA-based test may miss a signal.
Can a positive tTG test diagnose celiac disease?
Not by itself. A positive result raises suspicion, but diagnosis typically involves confirmatory evaluation, which may include additional antibody tests (such as EMA or DGP) and often an endoscopy with small-intestine biopsy. Your clinician will also consider your symptoms and diet.
Can I have celiac disease with a negative tTG result?
Yes. False negatives can happen if you are not eating gluten, if you have IgA deficiency and only IgA was measured, or if disease is mild or patchy. If your symptoms or risk factors are strong, your clinician may order total IgA, DGP antibodies, or other testing.
How long does it take for tTG antibodies to go down after going gluten-free?
It varies by person and by starting level, but antibodies often decline over months after strict gluten avoidance. Many clinicians recheck at intervals (for example, 6–12 months) to assess trend alongside symptoms and nutritional recovery.
Should I start a gluten-free diet if my tTG antibodies are high?
Do not make a permanent diet change solely based on one blood test without discussing confirmation with your clinician. Starting gluten-free before confirmatory testing can make diagnosis harder because antibody levels and biopsy findings can normalize over time.