Ordering Recommendation

Acceptable initial test to evaluate for suspected celiac disease (CD) in IgA-competent individuals. May aid in monitoring therapeutic response to a gluten-free diet in individuals with confirmed CD.

The preferred test to screen for CD or dermatitis herpetiformis (DH) 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.

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer 1.0 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 (tTG) Ab, IgA 0.00 - 4.99 FLU

Interpretive Data

Presence of the tissue transglutaminase (tTG) IgA antibody is associated with gluten-sensitive enteropathies such as celiac disease and dermatitis herpetiformis. Individuals with positive results should be confirmed with small intestinal biopsy to establish celiac disease diagnosis. tTG IgA antibody concentrations greater than 50 FLU exhibits higher correlation with results of duodenal biopsies consistent with celiac disease. For antibody concentrations greater than or equal to 5 FLU but less than 10 FLU, additional testing for endomysial (EMA) IgA concentrations may improve the positive predictive value for disease. A decrease in tTG IgA antibody concentration after initiation of a gluten-free diet may indicate a response to therapy.

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.

In patients with dermatitis herpetiformis (DH), uneven antibody patterns are possible. Concurrent CD reflexive panel testing and immunobullous disease panel testing are preferred to assess for DH.

Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
0097709 Tissue Transglutaminase (tTG) Ab, IgA 46128-5
* 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.


  • Human RBC tTG
  • Native tTG
  • TG2 IgA
  • Tissue Transglutaminase
  • Tissue Transglutaminase Ab IgA
  • tTG IgA
  • tTG, IGA
Tissue Transglutaminase Antibody, IgA