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Diagnosis Information

Adults

Download our adult diagnostic pathway card for information on diagnosis and the management of coeliac disease (CD).

Adult Coeliac disease diagnosis card Adult Coeliac disease diagnosis card (58 KB)

Children

Starship Children’s Health and Coeliac New Zealand have created a unique partnership to provide 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 Clincal 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
• +/- 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 certain. Over 99% of people affected by coeliac disease possess specific susceptibility genes (HLA DQ2 and/or HLA DQ8). Either one or both of these genes are present in virtually every person with coeliac disease. Various environmental factors are thought to play an important role in then triggering or "unmasking" coeliac disease in infancy, childhood or later in life.

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.

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.


If your patient is following a gluten free diet prior to testing:
 

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 (see 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.  


Point of Care Testing (PoCT)

Coeliac NZ has sought specialist advice on the suitability and reliability of PoCTs now available in NZ pharmacies. Our current stance is that we do not recommend PoCTs are adopted in routine clinical practice until further evidence is produced. For further information go to our PoCT page.