Tissue Transglutaminase Antibody, IgG
Ordering Recommendation
New York DOH Approval Status
Specimen Required
Serum separator tube (SST).
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)
Refrigerated.
Contaminated, grossly hemolyzed, grossly icteric, or grossly lipemic
After separation from cells: Ambient: 48 hours; Refrigerated: 1 week; Frozen: 30 days
Methodology
Semi-Quantitative Particle-Based Multianalyte Technology (PMAT)
Performed
Sun-Sat
Reported
1-2 days
Reference Interval
Test Number |
Components |
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.
FDA
Note
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
Hotline History
CPT Codes
86364
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0056009 | Tissue Transglutaminase Antibody,IgG | 56537-4 |
Aliases
- Tissue Transglutaminase
- Transglutaminase
- tTG
- tTG IgG