Deamidated Gliadin Peptide (DGP) IgG & IgA Test
A Deamidated Gliadin Peptide (DGP) IgG & IgA test measures the IgG and IgA immune responses to a gluten-related peptide together. Clinicians use these markers to help evaluate celiac disease as part of a larger, clinician-guided picture.
About this test
Gliadin is one of the proteins found in gluten, which is present in wheat, barley, and rye. In some people, the immune system reacts to a modified, or deamidated, form of this peptide by producing antibodies.
One important point sets antibody testing for celiac disease apart: it is generally done while a person is still eating gluten regularly. If gluten has already been removed from the diet, the immune markers can settle down and the picture becomes harder to interpret.
Who might consider this test?
- Look into DGP IgG and IgA when they or their clinician are exploring symptoms that can be associated with celiac disease
- Such as digestive discomfort
- When celiac disease runs in the family
Test details
| Quest code | 8889 |
|---|---|
| Methodology | Immunoassay |
| Sample type | 1 mL serum |
| Collection | Quest patient service center |
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Additional details
What this test looks at
The test measures IgG- and IgA-class antibodies directed at the deamidated gliadin peptide. Their presence reflects a particular kind of immune response related to gluten; it does not, by itself, establish a diagnosis. A clinician uses the pair as inputs, frequently alongside other antibody markers and, where appropriate, additional steps such as referral for further evaluation.
It helps to remember what antibody markers can and cannot do. They describe immune signals, not the full story of what is happening in the gut. That is exactly why celiac evaluation is guided by a clinician who can weigh several markers, symptoms, and history together rather than reading any one result in isolation.
Why measure both IgG and IgA
The two antibody classes can carry different information, and a person may show a response in one but not the other. Looking at both together gives a clinician a wider view and helps account for situations where one class is less informative — for example, when someone has an IgA shortage that can affect IgA-based markers. The combined result still needs a clinician's interpretation, but the broader view is part of why the pair is often ordered together.
Why gluten intake matters before testing
Celiac antibody markers generally reflect an ongoing immune response to gluten. When gluten is being eaten regularly, that response is more likely to be visible; when it has been removed, the markers can quiet down and the result becomes harder to interpret. For this reason people do not start a gluten-free diet on their own ahead of testing. Instead, they discuss timing with their clinician so the evaluation is planned and the results are meaningful. The sample is collected with a quick blood draw at a Quest patient service center.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does the DGP IgG & IgA test measure?
It measures IgG- and IgA-class antibodies to the deamidated gliadin peptide, two gluten-related immune markers. Clinicians use them together as inputs when evaluating celiac disease, alongside the wider clinical picture.
Why measure both IgG and IgA together?
The two antibody classes can carry different information, and looking at both gives a clinician a broader view. The IgG class is also useful when someone has a shortage of IgA that can affect IgA-based markers.
Do I need to be eating gluten before this test?
Celiac antibody markers generally reflect an ongoing response to gluten, so testing is usually done while a person is still eating gluten. People should talk with their clinician before changing their diet, so the timing is planned.
Does this test diagnose celiac disease?
No single antibody result establishes a diagnosis on its own. These markers are one part of a clinician-guided evaluation that may include other markers and further steps interpreted together.
How is the sample collected?
Through a routine blood draw at a Quest patient service center. A phlebotomist takes a small sample from a vein in the arm and sends it to the laboratory.
How much does the Gliadin Antibody test cost?
The cash price at Celio Health is $175. That covers the physician's order and sample collection at a Quest patient service center — no insurance is needed and there's no separate doctor's visit to pay for.