Gliadin Deamidated Antibody IgG (DGP-IgG) Biomarker Testing
It measures IgG antibodies to deamidated gliadin to help assess celiac risk, with convenient ordering and Quest-based lab access via Vitals Vault.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
Gliadin Deamidated Antibody IgG (often reported as DGP-IgG) is a blood test that looks for an immune response to a modified fragment of gluten. It is commonly used as part of celiac disease (celiac sprue) evaluation.
This test can be especially helpful when you have symptoms that could fit celiac disease but your other screening tests are negative or hard to interpret, such as when you have IgA deficiency. Your result is not a diagnosis by itself, but it can clarify whether celiac disease is more or less likely and what follow-up testing makes sense.
Because antibody levels can change with gluten exposure and with treatment (a strict gluten-free diet), timing matters. If you already stopped eating gluten, you may need a plan with your clinician for accurate testing.
Do I need a Gliadin Deamidated Antibody IgG test?
You may want this test if you have ongoing digestive symptoms such as chronic diarrhea, bloating, abdominal pain, nausea, or unexplained weight loss, and you and your clinician are considering celiac disease as a possible cause. It can also be relevant when symptoms are not mainly gastrointestinal, including iron-deficiency anemia, low bone density, fatigue, mouth ulcers, or certain rashes.
DGP-IgG is often considered when total IgA is low (selective IgA deficiency) or when tissue transglutaminase IgA (tTG-IgA) results are negative despite a strong clinical suspicion. In children and in some adults, it can add useful information alongside other celiac serology.
You generally get the most accurate antibody testing when you are eating gluten regularly. If you have been gluten-free for weeks to months, antibodies can fall and your result may look “normal” even if celiac disease is present.
This test is best used to support clinician-directed care and decisions about confirmatory testing (such as endoscopy with small-bowel biopsy), rather than for self-diagnosis.
This is a laboratory-developed immunoassay performed in a CLIA-certified lab; results should be interpreted with your symptoms, diet (gluten exposure), and companion celiac tests rather than used as a standalone diagnosis.
Lab testing
Order Gliadin Deamidated Antibody IgG testing through Vitals Vault.
Schedule online, results typically within about a week
Clear reporting and optional clinician context
HSA/FSA eligible where applicable
Get this test with Vitals Vault
Vitals Vault lets you order Gliadin Deamidated Antibody IgG testing without a referral and complete your blood draw at a participating lab location. Once results are in, you can keep them organized in one place so you can compare trends over time.
If your result is positive or confusing, PocketMD can help you understand what the number typically means, what other labs are commonly paired with it (like tTG-IgA, total IgA, or endomysial antibodies), and what questions to bring to your clinician. That is especially useful when you are deciding whether you need confirmatory testing or whether retesting timing should change based on your gluten intake.
If you are actively changing your diet, Vitals Vault also makes it easier to plan a follow-up test at an appropriate interval so you can see whether antibody levels are moving in the expected direction.
- Order online and test at a nationwide lab network
- PocketMD guidance to interpret results in context
- Easy reordering for follow-up testing and trend tracking
Key benefits of Gliadin Deamidated Antibody IgG testing
- Helps assess whether your immune system is reacting to gluten in a pattern consistent with celiac disease.
- Adds useful information when tTG-IgA is negative but symptoms or risk factors still point toward celiac disease.
- Supports evaluation when total IgA is low, where IgA-based celiac tests can be falsely reassuring.
- Can guide next steps, such as whether confirmatory endoscopy/biopsy should be discussed with your clinician.
- Provides a baseline before dietary changes so you can interpret future tests more accurately.
- Helps monitor antibody trends over time when you and your clinician are tracking response to a gluten-free diet.
- Pairs well with companion serology to reduce missed cases and avoid over-interpreting a single marker.
What is Gliadin Deamidated Antibody IgG?
Gliadin is a component of gluten, a protein found in wheat, barley, and rye. In celiac disease, the immune system reacts abnormally to gluten-related proteins and can damage the lining of the small intestine.
“Deamidated gliadin peptides” (DGP) are gliadin fragments that have been modified (deamidated) by an enzyme called tissue transglutaminase. This modification can make the peptides more likely to trigger an immune response in people with celiac disease. The DGP-IgG test measures IgG-class antibodies your immune system may produce against these deamidated gliadin peptides.
A positive DGP-IgG does not prove celiac disease on its own, because antibody results can be influenced by your diet, other immune conditions, and the specific test method. However, when it is interpreted alongside symptoms and other celiac serology, it can meaningfully change the likelihood that celiac disease is present and help determine what to do next.
How DGP-IgG fits into celiac testing
Many clinicians start with tTG-IgA plus a total IgA level, because tTG-IgA is a strong screening test when IgA is normal. DGP-IgG is commonly used as an additional tool when IgA is low, when results are discordant, or when clinical suspicion remains high despite negative initial screening.
Why gluten exposure matters
Antibodies are a response to exposure. If you have already removed gluten from your diet, DGP-IgG can decrease over time, which may lead to a normal result even if celiac disease is the underlying issue. If you are considering testing, talk with your clinician before changing your diet, or ask about a supervised “gluten challenge” if you are already gluten-free.
What do my Gliadin Deamidated Antibody IgG results mean?
Low (negative) Gliadin Deamidated Antibody IgG
A low or negative result usually means your immune system is not showing an IgG antibody response to deamidated gliadin at the time of testing. This lowers the likelihood of celiac disease, especially if you were eating gluten regularly and other celiac tests are also negative. However, it does not fully rule out celiac disease in every situation, such as early disease, limited gluten exposure, or testing after you started a gluten-free diet. If symptoms persist, your clinician may still consider additional testing or repeat testing under the right dietary conditions.
In-range (within the lab’s reference interval)
Most labs report DGP-IgG as negative, borderline/equivocal, or positive rather than “optimal,” but an in-range result is generally treated as negative. When your result is in range and you are eating gluten, it is reassuring, particularly when paired with a normal tTG-IgA and normal total IgA. If your result is borderline, your clinician may repeat the test, add companion markers, or focus on whether you had enough gluten exposure for the result to be meaningful.
High (positive) Gliadin Deamidated Antibody IgG
A high or positive result means your immune system is producing IgG antibodies to deamidated gliadin peptides. This can increase suspicion for celiac disease, especially if you have compatible symptoms, a family history, or other positive celiac markers. The usual next step is to interpret it alongside tTG-IgA (and total IgA) and discuss whether confirmatory testing, such as endoscopy with biopsy, is appropriate. Do not start or stop gluten solely based on this single result without a plan, because diet changes can make confirmation harder.
Factors that influence DGP-IgG
Your current gluten intake is one of the biggest drivers of the result; reduced or absent gluten can lower antibodies over time. IgA deficiency can make IgA-based tests less reliable, which is one reason DGP-IgG is sometimes ordered. Age, immune system conditions, and differences between lab methods can also affect results, especially near the cutoff. Finally, antibody tests are not perfect, so discordant patterns (one positive, others negative) should be worked through with symptoms, risk factors, and sometimes confirmatory procedures.
What’s included
- Gliadin (Deamidated) Ab (Igg)
Frequently Asked Questions
Is DGP-IgG the same as a gluten intolerance test?
Not exactly. DGP-IgG is used to assess immune reactivity patterns that can be consistent with celiac disease, which is an autoimmune condition. Non-celiac gluten sensitivity does not have a single validated blood test, and symptoms can overlap with other conditions.
Do I need to be eating gluten before a Gliadin Deamidated Antibody IgG test?
Usually, yes. Antibody tests are most informative when you are eating gluten regularly, because antibodies can fall on a gluten-free diet. If you have already stopped gluten, talk with your clinician about whether and how long a gluten challenge is appropriate before testing.
What other tests are commonly ordered with DGP-IgG for celiac disease?
Common companion tests include tissue transglutaminase IgA (tTG-IgA) and a total IgA level to check for IgA deficiency. Some clinicians also use endomysial antibody IgA (EMA-IgA) or DGP-IgA depending on age, symptoms, and prior results. Definitive diagnosis may require endoscopy with small-intestine biopsy in many cases.
Can DGP-IgG be positive if I do not have celiac disease?
Yes. No antibody test is perfect, and false positives can occur, especially when the result is only mildly elevated or when the pre-test likelihood of celiac disease is low. That is why clinicians interpret DGP-IgG alongside symptoms, other serology, and sometimes confirmatory testing.
If my DGP-IgG is negative, can I rule out celiac disease?
A negative result lowers the likelihood, particularly if you were eating gluten and other celiac tests are negative. However, celiac disease can still be present in some situations, such as limited gluten exposure, early disease, or testing after starting a gluten-free diet. Persistent symptoms or strong risk factors may warrant additional evaluation.
How long does it take for DGP-IgG to go down after going gluten-free?
Antibody levels often decline over months, but the timeline varies by person and by how strict and consistent the gluten-free diet is. Some people see meaningful drops within 3–6 months, while others take longer. Your clinician may use repeat testing plus symptom response and nutrition status to assess progress.
Do I need to fast for a DGP-IgG blood test?
Fasting is not typically required for antibody testing like DGP-IgG. If your blood draw includes other tests (such as lipids or glucose), fasting instructions may apply to the overall order, so follow the directions provided for your panel.