Tissue Transglutaminase (tTG) IgG

Ordering Recommendation

Recommended single screening test for IgA-deficient individuals with suspected celiac disease. (IgA testing recommended to identify IgA deficiency.)

May aid in monitoring adherence to gluten-free diet in celiac disease confirmed patients.

Mnemonic

Methodology

Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Performed

Mon-Sat

Reported

1-2 Days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation:

Collect:

Serum separator tube (SST).

Specimen Preparation:

Remove serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to a Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature:

Refrigerated

Unacceptable Conditions:

Refrigerated.

Remarks:

Plasma. Hemolyzed or severely lipemic specimens.

Stability:

After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year

Reference Interval

5 U/mL or less

6-9 U/mL

Negative

Weak Positive

10 U/mL or greater

Positive

Interpretive Data

The tTG IgG assay may aid in the diagnosis of gluten-sensitivity enteropathy (i.e., celiac disease, dermatitis herpetiformis) in tTG IgA negative patients with confirmed IgA deficiency. A negative tTG IgG test alone does not rule out gluten-sensitive enteropathy.

Note

Human recombinant tTG antigen is utilized in this assay

CPT Code

86364

Components

Component Chart Name

Tissue Transglutaminase (tTG) Ab, IgA

Component Test Code

0056009

LOINC

56537-4

Aliases

Tissue Transglutaminase
Transglutaminase
tTG
tTG IgG