What does the Tissue Transglutaminase IgA Antibody test measure?

Why is Tissue Transglutaminase IgA Antibody measured?

tTG-IgA is the single most sensitive and specific serological marker for coeliac disease, recommended as the first-line test in both symptomatic and at-risk populations. Sensitivity exceeds 90 per cent in patients with villous atrophy, though it may be lower in mild enteropathy. A positive result in the appropriate clinical or genetic context prompts referral for small bowel biopsy, the diagnostic gold standard, while a negative result in an IgA-sufficient individual makes active coeliac disease unlikely.

Reference ranges

Standard reference

<4 U/mL negative; 4–10 U/mL equivocal; >10 U/mL positive (laboratory-specific thresholds apply).

Functional medicine optimal

Undetectable (<4 U/mL) in the absence of coeliac disease and adherence to a normal gluten-containing diet; equivocal results warrant repeat testing or consideration of biopsy.

Units

U/mL

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.