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HelpTest Code TSTGP Tissue Transglutaminase Antibodies, IgA and IgG Profile, Serum
Reporting Name
Tissue Transglutaminase Ab, IgA/IgGUseful For
Evaluating patients suspected of having celiac disease, including patients with compatible clinical symptoms, patients with atypical symptoms, and individuals at increased risk (family history, previous diagnosis with associated disease, positivity for HLA DQ2 and/or DQ8)
Screening for dermatitis herpetiformis, in conjunction with endomysial antibody test
Monitoring response to gluten-free diet in patients with dermatitis herpetiformis and celiac disease
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| TTGA | Tissue Transglutaminase Ab, IgA, S | Yes | Yes |
| TTGG | Tissue Transglutaminase Ab, IgG, S | Yes | Yes |
Testing Algorithm
The following algorithms are available:
-Celiac Disease Comprehensive Cascade Test Algorithm
-Celiac Disease Diagnostic Testing Algorithm
-Celiac Disease Gluten-Free Cascade Test Algorithm
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumOrdering Guidance
Cascade testing is recommended for celiac disease. Cascade testing ensures that testing proceeds in an algorithmic fashion. The following cascades are available; select the appropriate one for your specific patient situation.
-CDCOM / Celiac Disease Comprehensive Cascade, Serum and Whole Blood: complete testing including HLA DQ
-CDSP / Celiac Disease Serology Cascade, Serum: complete serology testing excluding HLA DQ
-CDGF / Celiac Disease Gluten-Free Cascade, Serum and Whole Blood: for patients already adhering to a gluten-free diet
To order individual tests, see Celiac Disease Diagnostic Testing Algorithm
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 21 days | |
| Frozen | 21 days |
Special Instructions
Reference Values
tTG ANTIBODY, IgA
<4.0 U/mL (negative)
4.0-10.0 U/mL (weak positive)
>10.0 U/mL (positive)
Reference values apply to all ages.
tTG ANTIBODY, IgG
<6.0 U/mL (negative)
6.0-9.0 U/mL (weak positive)
>9.0 U/mL (positive)
Reference values apply to all ages.
Day(s) Performed
Monday through Saturday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86364 x 2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TSTGP | Tissue Transglutaminase Ab, IgA/IgG | 35681-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| TTGA | Tissue Transglutaminase Ab, IgA, S | 46128-5 |
| TTGG | Tissue Transglutaminase Ab, IgG, S | 56537-4 |
Interpretation
Positive results for tissue transglutaminase (tTG) IgA or IgG antibodies are consistent with a diagnosis for celiac disease and possibly for dermatitis herpetiformis. For individuals with moderately to strongly positive results, a diagnosis of celiac disease is possible and a small intestinal biopsy should be considered to confirm the diagnosis.
Negative results for tTg IgA and IgG antibodies indicate a decreased likelihood of celiac disease.
A decrease in the concentration of tTG IgA or IgG may begin after initiation of a gluten-free diet and could indicate a response to therapy.
Clinical Reference
1. Rubin JE, Crowe SE: Celiac disease. Ann Int Med. 2020;172:ITC1-ITC16
2. Lebwohl B, Rubio-Tapia A: Epidemiology, presentation, and diagnosis of celiac disease. Gastroenterol. 2021;160:63-75
3. Rubio-Tapia A, Hill ID, Kelly, CP, et al: American College Gastroenterology clinical guidelines: Diagnosis and management of celiac disease. Am J Gastroenterol. 2013;108:656-676
4. Penny HA, Raju SA, Sanders DS: Progress in the serology-based diagnosis and management of adult celiac disease. Exp Rev Gastroenterol Heptatol. 2020;14:147-154
Report Available
Same day/1 to 4 daysMethod Name
Enzyme-Linked Immunosorbent Assay (ELISA)
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.