Coeliac Disease: Serological tests

From: www.patient.co.uk


NICE Clinical Guidelines (UK)

Serological tests

1.1.12 All tests should be undertaken in laboratories with clinical pathology accreditation (CPA).

1.1.13 Do not use immunoglobulin G (IgG) or immunoglobulin A (IgA) anti-gliadin antibody (AGA) tests in the diagnosis of coeliac disease.

1.1.14 Do not use of self-tests and/or point-of-care tests for coeliac disease as a substitute for laboratory-based testing.

1.1.15 When clinicians request serology, laboratories should:
• use IgA tissue transglutaminase (tTGA) as the first choice test
• use IgA endomysial antibodies (EMA) testing if the result of the tTGA test is equivocal
• check for IgA deficiency if the serology is negative1
• use IgG tTGA and/or IgG EMA serological tests for people with confirmed IgA deficiency
• communicate the results clearly in terms of values, interpretation and recommended action.

1.1.16 Do not use human leukocyte antigen (HLA) DQ2/DQ8 testing in the initial diagnosis of coeliac disease. (However, its high negative
1 Investigation for IgA deficiency should be done if the laboratory detects a low or very low optical density on IgA tTGA test or low background on IgA EMA test.
NICE clinical guideline 86 Coeliac disease 13
predictive value may be of use to gastrointestinal specialists in specific clinical situations.)

After serological testing
1.1.17 Offer referral to a gastrointestinal specialist for intestinal biopsy to confirm or exclude coeliac disease to people with positive serological results from any tTGA or EMA test.
1.1.18 If serology tests are negative but coeliac disease is still clinically suspected, offer referral to a gastrointestinal specialist for further assessment.