Ordering Recommendation

Acceptable test to evaluate for suspected celiac disease (CD) in IgA-deficient individuals. Use in conjunction with Deamidated Gliadin Peptide (DGP) Antibody, IgG (0051359) is recommended.

The preferred test to screen for CD is Celiac Disease Reflexive Cascade, Serum (3016817).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube (SST).

Specimen Preparation

Remove serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP standard transport tube. (Min: 0.5 mL)

Storage/Transport Temperature


Unacceptable Conditions

Contaminated, grossly hemolyzed, grossly icteric, or grossly lipemic


After separation from cells: Ambient: 48 hours; Refrigerated: 1 week; Frozen: 30 days


Semi-Quantitative Particle-Based Multianalyte Technology (PMAT)




1-2 days

Reference Interval

Test Number
Reference Interval
  Tissue Transglutaminase Antibody,IgG 0.00 - 4.99 FLU

Interpretive Data

In individuals with low or deficient IgA, testing for tissue transglutaminase (tTG) and deamidated gliadin (DGP) antibodies of the IgG isotype is performed. A positive tTG and/or DGP IgG antibody results indicate celiac disease, however, small intestinal biopsy is required to establish a diagnosis due to the lower accuracy of these markers, especially in patients without IgA deficiency.

Compliance Category



In individuals who produce sufficient total IgA, the most sensitive and specific serologic test for celiac disease (CD) diagnosis is tissue transglutaminase (tTG) IgA. In individuals who are IgA deficient, tTG IgG and deamidated gliadin peptide (DGP) IgG antibody testing is recommended.

Reflexive panel testing is preferred to screen for CD.

All serologic tests used to diagnose CD should be performed while the patient is on a gluten-containing diet. Upon initiation of a gluten-free diet, antibody titers decline in treatment-responsive patients, and the time frame to normalize titers varies by case. If serology is negative and suspicion for CD remains strong, intestinal biopsy may still be warranted to establish a diagnosis.

Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
0056009 Tissue Transglutaminase Antibody,IgG 56537-4
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Tissue Transglutaminase
  • Transglutaminase
  • tTG
  • tTG IgG
Tissue Transglutaminase Antibody, IgG