Deamidated Gliadin Peptide (DGP) IgG Antibody Test
A Deamidated Gliadin Peptide (DGP) IgG antibody test measures an IgG-class immune response to a gluten-related peptide. Clinicians use it as one marker to help evaluate celiac disease, and it is interpreted 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. This test looks specifically at the IgG class of that response. Antibody markers like this one are part of how clinicians approach celiac disease, an immune condition in which eating gluten leads to a reaction affecting the small intestine. The DGP IgG marker is one tool among several, and it is always read alongside other findings rather than on its own.
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. Because of this, people talk with their clinician before making any dietary changes, so the timing of the test is planned rather than accidental. The sample itself is collected with a simple blood draw at a Quest patient service center.
Who commonly orders it
People often look into DGP IgG when they or their clinician are exploring symptoms that can be associated with celiac disease, such as digestive discomfort, fatigue, or other concerns, or when celiac disease runs in the family. The IgG version can be particularly relevant for people who have a shortage of the IgA antibody class, because some other celiac markers rely on IgA and may be less informative in that situation. Because celiac evaluation is nuanced, this marker is chosen and interpreted with a clinician rather than used as a standalone answer.
What this test looks at
The test measures IgG-class antibodies directed at the deamidated gliadin peptide. Its presence reflects a particular kind of immune response related to gluten; it does not, by itself, establish a diagnosis. A clinician uses it as one input, frequently alongside other antibody markers and, where appropriate, additional steps such as referral for further evaluation.
It helps to remember what an antibody marker can and cannot do. It describes an immune signal, 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.
Why gluten intake matters before testing
Celiac antibody markers, including DGP IgG, 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.
What to expect at your visit
No appointment is needed for the draw itself. People can walk into a Quest patient service center during open hours, and a phlebotomist collects a small sample from a vein in the arm, with most visits wrapping up in a few minutes. Once the laboratory completes its analysis, the result is posted to the account, where it can be reviewed and shared with a clinician who can place it within the broader celiac evaluation.
Your results
Results will be emailed securely to you as a PDF.
One-time price · physician order included · no insurance needed
Prefer a fuller panel?
A curated bundle groups this test with the markers clinicians most often review alongside it — often better value than single tests.
Frequently asked questions
What does the DGP IgG antibody test measure?+–
It measures IgG-class antibodies to the deamidated gliadin peptide, a gluten-related immune marker. Clinicians use it as one input when evaluating celiac disease, alongside other markers and the clinical picture.
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.
Why choose the IgG version?+–
The IgG class can be especially useful for people who have a shortage of IgA, since some other celiac markers rely on IgA and may be less informative in that situation. A clinician helps decide which markers fit.
Does this test diagnose celiac disease?+–
No single antibody marker establishes a diagnosis on its own. DGP IgG is 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 is a Gliadin Antibody test?+–
$175, paid once at checkout. The price includes the physician's order this test requires and sample collection at any of 2,300+ Quest patient service centers nationwide.