Up to 10% of people diagnosed with Coeliac Disease also suffer from Thyroid Autoimmune Disease, either Hashimoto’s – underactive or hypothyroid or Graves’ Diseases – overactive or hyperthyroid. The close relationship between Coeliac Disease and Thyroid Autoimmune Disease can be largely explained by sharing of a common genetic predisposition and a familial connection.

It is estimated that 1 in 70 Australians live with Coeliac Disease, yet concerningly approximately 80% of these individuals remain undiagnosed. According to existing research, the common genetic background is the key factor influencing this high incidence of association.

Although Coeliac Disease is often considered a digestive issue, the reality is that, as a ‘clinical chameleon’…it can present with a large variety of different symptoms; some obvious, some more subtle.

The gap in diagnosis, highlights the need for increased awareness and understanding of the wide-ranging symptoms of the disease, extending beyond the conventional gastrointestinal signs and the importance of diagnosis to improve health outcomes.

Please be aware of the connection between Coeliac and Thyroid Autoimmune Diseases. If you have any obvious or underlying symptoms, or are concerned, ask your doctor to order pathology tests to determine or eliminate a diagnosis.

Q. Does a Gluten Free Diet help patients who have Thyroid Autoimmune Disease – reduce inflammation etc.

The answer is no. Elimination diets have recently become extremely popular among people with autoimmune diseases and are widely recommended on social media and by some other health professionals without any good scientific evidence to support these recommendations. While there is no evidence that a gluten free diet will provide any significant, evidence-based, health/medical benefits to people who do not also suffer from gluten intolerance/coeliac disease, many people in our society may feel better while adhering to a gluten free diet, not because of any reduction in inflammation in the body, but because their overall digestion is improved with less production of intestinal gas and less abdominal swelling and less abdominal discomfort. Thus, adoption of a gluten free diet without any evidence for coeliac disease or gluten intolerance is a personal decision and is not based on scientific evidence and does not confirm the person has coeliac disease. However, given the strong familial association of coeliac disease and autoimmune thyroid disease (see below) there will be many people in the community who are suffering from undiagnosed coeliac disease, so if a person thinks he/she will benefit from a gluten free diet then it would be wise to ask their doctor to screen them for coeliac disease before commencing a gluten free diet. Testing for these immunological biomarkers for coeliac disease is called “coeliac serology” and it is imperative that the patient is consuming a diet with gluten in it at the time of testing to avoid “false negative” test results that may occur when the person is adhering to a “gluten-free diet”.

As more than 99% of people who develop coeliac disease have a genetic predisposition to this disorder then if a person tests negative to this genotype, then it is virtually impossible for that person to develop coeliac disease. So, the HLA test can be used to exclude the likelihood of developing coeliac disease, but it cannot be used to confirm a diagnosis. This test is the human leukocyte antigen (HLA) test, and the genotype markers for coeliac disease are HLA-DQ2 and HLA-DQ8.

References:

Lewis D, Hardy J, Newnham ED. Testing for coeliac disease. Aust Prescriber 2017;40:105-8.https://doi.org/10.18773/austprescr.2017.029