Ep 101 – Coeliac disease

Coeliac disease (CD) is a chronic autoimmune disorder that primarily affects the small intestine and is triggered by the consumption of gluten, a protein found in wheat, barley, rye and sometimes oats. When individuals with CD ingest gluten, their immune system responds by damaging the lining of the small intestine. This damage impairs the absorption of nutrients from food, leading to various symptoms and potentially serious complications. In this episode, Dr Roger Henderson looks at the diagnosis, testing and management of CD, along with the importance of longer-term follow-up in people with it.

Key references

1. NICE. Guideline. Coeliac disease: recognition, assessment and management (NG20). 2 September 2015.
2. Al-Toma A, et al. United European Gastroenterol J. 2019;7(5):583-613. doi: 10.1177/2050640619844125.
3. Gray AM and Papanicolas IN. BMC Health Serv Res. 2010;10:105. doi: 10.1186/1472-6963-10-105.
4. Lewis NR and Scott BB. Aliment Pharmacol Ther. 2006;24(1):47-54. doi: 10.1111/j.1365-2036.2006.02967.x.
5. NICE. Treatment summaries. Coeliac disease. (Accessed 17 April 2024).
6. Kreutz JM, et al. Nutrients. 2020;12(2):500. doi: 10.3390/nu12020500.

Key take-home points

• 1% of the UK population has CD, but up to 80% of these are undiagnosed.
• In the last 50 years, the prevalence of CD has increased.
• Gluten ingestion may be associated with a range of clinical disorders, known collectively as “gluten-related disorders”.
• Up to 30% of adults with CD will continue to have persistent symptoms, signs or laboratory abnormalities of the condition despite a gluten free diet for at least 6-12 months.
• Dermatitis herpetiformis is a skin manifestation of CD and may not always clear once gluten is withdrawn from the diet.
• Anyone with signs or symptoms suggesting malabsorption should be serologically tested for CD, as well as anyone with type 1 diabetes or autoimmune thyroid disease.
• The test of choice in CD is serological testing, specifically the IgA transglutaminase 2 (TG2) antibody test. IgA endomysial antibody (EMA) testing should be carried out if this is weakly positive.
• A positive serological test is defined as an unambiguously positive IgA TG2 alone, or a weakly positive IgA TG2 and a positive IgA EMA result.
• Improvement or exacerbation of symptoms after gluten withdrawal or reintroduction has a very low predictive value and so should not be used to make a diagnosis of CD in the absence of other supportive evidence.
• Always advise patients that any test for CD is only accurate if a gluten-containing diet is eaten during the diagnostic process, and that they should not start a gluten-free diet until their diagnosis has been confirmed by a specialist even if their serological test results are positive.
• Young people and adults who have positive CD serology should be referred to a gastroenterologist for endoscopic intestinal biopsy to confirm or exclude the diagnosis.
• Treatment with a lifelong strict gluten-free diet is currently the only known effective treatment for coeliac disease.
• Patients should be educated to avoid any cereal or food product derived from wheat, barley or rye, including gluten-contaminated cereal foodstuffs that are normally gluten-free such as oats and maize.
• Oats that are uncontaminated by gluten are very safe for almost all patients with CD, although there may be a very small percentage who are very sensitive to them and who develop symptoms if ingested.
• Patients with a new diagnosis of CD should be tested to check for deficiencies in essential micronutrients.
• Up to 80% of patients with CD have an iron-deficiency at diagnosis (CD is present in up to 5% of people with iron-deficiency anaemia) but this improves on a strict gluten free diet – as does vitamin B12 deficiency, found in up to 40% of cases of untreated CD.
• All patients diagnosed with CD should be encouraged to join national coeliac societies or other coeliac support groups.
• Once the disease has been stabilised and dietary alterations have become routine, annual or biannual follow up is advised along with checks for thyroid disorders and liver disease, and antibody checks to assess dietary adherence.