Deamidated Gliadin Peptide (DGP) Antibodies, IgA and IgG

Casandra

Casandra Test Code AR93680Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 0051358CPT Code 86258

Deamidated Gliadin Peptide (DGP) Antibodies, IgA and IgG

Also known as: GLIAD PAN

Clinical Use

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Use

The Deamidated Gliadin Peptide (DGP) Antibodies test measures the presence of IgA and IgG antibodies against deamidated gliadin peptides, which can be indicative of celiac disease. This test is particularly important for evaluating patients who are suspected of having celiac disease but should not be used as an initial screening tool due to its lower specificity compared to other tests like tissue transglutaminase (tTG) IgA. In individuals who are IgA deficient, DGP IgG testing may be recommended alongside tTG IgG. The presence of these antibodies is associated with celiac disease, but a positive result needs to be confirmed with a small intestinal biopsy for an accurate diagnosis.

Special Instructions

The test should be conducted on patients currently consuming a gluten-containing diet, as antibody levels tend to decline with a gluten-free diet. Reflexive panel testing is preferred for initial screening of celiac disease. The test requires separation of serum from cells within two hours of collection, and it is necessary to store the serum under refrigerated conditions during transportation.

Limitations

Deamidated gliadin peptide (DGP) IgA and IgG tests should not be used as initial screening tests due to their lower sensitivity and specificity compared to other serological tests such as tTG IgA. Some patients with positive tTG IgA results may have negative results for DGP IgA and/or endomysial antibody (EMA) IgA, which may indicate early disease or false positivity. Serological testing should be performed while the patient is consuming gluten as elimination of gluten can lead to decreased antibody levels, affecting the accuracy of the test.

Test Details

New York Approved