Interpretation
IgA antibodies to TTG are useful in the diagnosis and follow-up of coeliac disease. They are highly disease specific markers for untreated coeliac disease providing patients are on a normal (gluten containing) diet.
Some controversy exists over optimal testing strategy for patients with suspected coeliac disease. Current practice tests IgA anti-TTG as the first line followed by IgA endomysial antibodies if IgA anti-TTG are equivocal or positive.
In adults it is recommend that patients with positive titres be referred for specialist clinical assessment and confirmation by small bowel biopsy before any treatment is undertaken.
Children with positive TTG above 10x upper limit of normal may be eligible for biopsy-free diagnosis of coeliac disease pending further serological testing and Paediatric Gastroenterology confirmation. Small bowel biopsy remains the gold standard for diagnosis of coeliac disease in relevant children with positive TTG below 10x upper limit of normal. Recommend referral to local Paediatrics/Paediatric Gastroenterology service for further assessment.
Patients with IgA deficiency will give negative results, therefore, testing for IgG TTG is useful and will be automatically testing where IgA deficiency is detected.
Anti-TTG may be useful in monitoring dietary compliance.
Test Method
Fluorescence Enzyme Immunoassay (FEIA)
