Tissue Transglutaminase Antibody, IgG
Also known as: TTG G
Use
This test is used to evaluate for suspected celiac disease in individuals who are IgA-deficient. It is recommended to be used alongside Deamidated Gliadin Peptide (DGP) Antibody, IgG for more effective screening in such cases. Although a positive Tissue Transglutaminase (tTG) IgG antibody may indicate celiac disease, a small intestinal biopsy is necessary to confirm the diagnosis, especially given the lower accuracy of these tests in non-IgA deficient patients.
Special Instructions
This test is New York state approved. The tissue transglutaminase IgG test is most effective when other serological tests like tTG IgA are not viable due to IgA deficiency. It should ideally be performed when the patient is on a gluten-containing diet to ensure accurate antibody detection. Ensure serum is removed from cells within 2 hours of collection to avoid contamination.
Limitations
The accuracy of tTG and DGP IgG antibodies is lower compared to tTG IgA in non-IgA deficient individuals. It's crucial that the patient remains on a gluten-containing diet during testing because antibody levels decline with gluten-free diets. Even with negative serology, if clinical suspicion of celiac disease is strong, further investigation with an intestinal biopsy may be necessary.
New York Approved
Methodology
Immunoassay (Multiplex Protein Panel)
Biomarkers
LOINC Codes
- 56537-4
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP standard transport tube
Collection Instructions
Collect in a serum separator tube (SST).
Storage Instructions
Refrigerated.
Causes for Rejection
Contaminated, grossly hemolyzed, grossly icteric, or grossly lipemic
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 1 week |
| Frozen | 30 days |