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Doctor referral letter

Dear Doctor,

Your patient has completed the Coeliac Australia online self assessment for coeliac disease.

The selected responses indicate an increased risk of coeliac disease.

Based on the information provided, and with reference to the NICE 2015 testing guidelines1 , we would recommend SCREENING FOR COELIAC DISEASE.

How to test for coeliac disease

  1. Confirm a gluten-containing diet is being followed for accurate results.
  2. Request the following blood test:
      • Coeliac serology, specifically:
        • Transglutaminase-IgA (tTG-IgA)
        • Deamidated gliadin peptide-IgG (DGP-IgG)
      • When screening high risk individuals with a positive family history of coeliac disease, consider also requesting HLA-DQ2/8 genotyping.

    Scroll down for results interpretation and what to do if your patient is not consuming gluten regularly.

    Thank you for your care.

Yours sincerely, Dr Jason Tye-Din MBBS, FRACP, PhD
Chair, Medical Advisory Committee of Coeliac Australia

Coeliac disease: recognition, assessment and management , NICE guideline NG20,

How to interpret coeliac serology results

  • If tTG-IgA and/or DGP-IgG is elevated (positive) refer to a gastroenterologist for gastroscopy and small bowel biopsy to confirm the diagnosis. Serology alone is insufficient to diagnose coeliac disease.
  • Approximately half of the general population is HLA-DQ2/8 positive so this test cannot be used to make a diagnosis of coeliac disease. However, if HLA-DQ2/8 gene testing is negative coeliac disease can be confidently excluded (<1% chance).
  • If coeliac serology is negative but the patient is symptomatic and positive for HLA-DQ2 and/or HLA-DQ8 then consider referral to a gastroenterologist for further work-up.
  • A HLA-DQ2 and/or HLA-DQ8 positive relative with normal coeliac serology is at-risk for the future development of coeliac disease and ongoing follow-up is warranted. Repeat screening is recommended if they become symptomatic e.g. gastrointestinal upset, lethargy, anaemia.

If your patient is on a gluten free diet prior to testing

Option 1 – Recommend a gluten challenge: your patient needs to return to a gluten containing diet (at least 3-6g gluten daily, or equivalent of 2-4 slices of wheat-based bread per day (2 for a child), for at least 4 weeks before testing).

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 feasible diagnostic approach.