ARUP's Laboratory Test Directory

Tissue Transglutaminase Antibody, IgG : 0056009

Mnemonic: TTG G

Ordering Recommendation: Use in IgA-deficient individuals; recommended single screening test for celiac disease. In confirmed disease, this test may be used for monitoring.
Methodology: Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Performed: Sun-Sat
Reported: 1-2 days
Specimen Required: Collect: Serum separator tube.

Specimen Preparation: 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)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Plasma. Hemolyzed or severely lipemic specimens.

Stability (collection to initiation of testing): After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year
Reference Interval:
< 20 EU: None Detected
20-30 EU: Weakly Positive
> 30 EU: 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: Native human tTG antigen is utilized in this assay
CPT Code(s): 83516