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A conclusive diagnosis of Coeliac Disease is vital for its management

Tests available for Coeliac Disease


As coeliac disease (CD) is a serious medical condition with lifelong complications, a conclusive diagnosis is vital for its management. There are a number of tests available to diagnose coeliac disease. If you are an adult, you can refer to our adult diagnostic pathway card for more information.

For children, Starship Children’s Health and Coeliac New Zealand have created a unique partnership to offer better community support and care for children with coeliac disease. This has included the development of a new regional clinical pathway, for children who live in the Auckland, Waitemata and Counties Manukau District Health Board regions. Download the Auckland Region Paediatric Clinical Pathway here.

Tests Available for Coeliac Disease

Coeliac serology:
Confirm your patient is consuming a gluten containing diet for accurate results. Request coeliac disease serology specifically: IgA-tTG (tissue transglutaminase), +/- Endomysial antibodies, and +/- Deamidated gliadin peptide antibodies (will depend on local laboratory).
Gene testing:
HLA DQ2/DQ8Gene (HLA) testing is a useful tool in cases when the diagnosis of coeliac disease is not conclusive. In these circumstances the test is only useful if it is negative, in which case coeliac disease can be excluded. At least 95%, and perhaps as many as 99% of people affected by coeliac disease possess either one or both of the specific susceptibility genes HLA DQ2 and/or HLA DQ8. However, between 30% and 50% of the population who will never develop coeliac disease will also be HLA DQ2 or DQ8 positive therefore a positive test cannot be used to confirm the diagnosis of coeliac disease. The gene test does not rely on a person eating gluten so can be used when people have already commenced a gluten free diet and find it very difficult to do a gluten challenge. If the HLA test is negative then there is no need to persist with a gluten challenge as coeliac disease is not the cause of their symptoms. A positive gene test is not a diagnosis of CD. If the gene test is positive for HLA DQ2 or HLA DQ8, then a gluten challenge followed by a small bowel biopsy will be required to diagnose coeliac disease. A biopsy/endoscopy remains the gold standard for diagnosis at this point in time.

Following a Gluten Free Diet Prior to Testing

The 2 Options
There are two options.

Option 1: Recommend a gluten challenge. If gluten has already been removed from the diet, a normal gluten containing diet must be resumed for at least 4-6 weeks prior to serology testing and biopsy (refer to the diagnostic card). During this ‘gluten challenge’, a minimum of four slices of wheat based bread (or equivalent) should be consumed each day for 4 weeks, by adults.

Two slices of wheat based bread each day for children, or gluten in at least two meals/day for 4-6 weeks. It is important the gluten challenge is carried out properly to ensure reliable test results.

Option 2: If your patient is reluctant or unable to complete a gluten challenge, offer HLA-DQ2/ 8 gene testing. If HLA DQ2/ 8 gene testing is negative coeliac disease can be safely excluded. If it is positive, then option 1 is the only diagnostic approach.




"By taking the first step to gain a diagnosis, you can be confident that your symptoms are caused by CD. You can, therefore, receive the necessary support, information, and means to thrive on a gluten free diet."

A gluten free diet is not a negligible nor simple undertaking, as it brings about lifestyle changes and learning new skills such as reading and interpreting food labels. It should only be undertaken after the diagnosis of coeliac disease has been definitively and medically confirmed.



Keep up to date with coeliac disease and the latest research. Become part of Coeliac New Zealand now.



Become a member of CNZ as a health professional and receive updates regarding the latest in coeliac disease and gluten free foods. 



Access the online course for Physicians & Dietitians developed by the Division for Pediatric Gastroenterology & Hepatology, Munich, Germany.




We are always on the look-out for passionate people interested in raising funds and building awareness about coeliac disease


About Coeliac New Zealand


Your partner in
healthy living

Coeliac New Zealand is available throughout your journey. As part of our community, you’ll get support, advice, and assistance. We work with health professionals, manufacturers, and researchers to raise awareness of coeliac disease in NZ.

Together, we can reach a day when every person with coeliac disease gets diagnosed quickly, lives a healthy life, and has the prospect of a cure.


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