Coeliac Disease

Definition/diagnostic criteria Coeliac disease is a chronic autoimmune condition triggered by the ingestion of gluten, found in wheat, barley, and rye, leading to inflammation and villous atrophy in the small intestine. The diagnosis of coeliac disease should be considered in individuals with suggestive clinical features, positive coeliac serology (tissue transglutaminase IgA antibody [tTG-IgA] or endomysial antibodies [EMA]), and is confirmed by the presence of enteropathy on duodenal biopsy.

Epidemiology Coeliac disease affects approximately 1% of the population in the UK, with a noted higher prevalence in females and in first-degree relatives of those with the condition. The presentation can occur at any age, although it is most commonly diagnosed in individuals aged between 40 and 60 years.

Diagnosis

Clinical Features

Symptoms of coeliac disease are diverse, ranging from classical gastrointestinal manifestations such as diarrhoea, bloating, and weight loss, to more atypical and non-gastrointestinal manifestations including anaemia, dermatitis herpetiformis, and neurological disturbances. Asymptomatic individuals may also be diagnosed incidentally through screening.

Investigations

Diagnosis involves serological testing, with IgA tTGA being the recommended screening test. Use serum IgA endomysial antibody (EMA) second-line, if IgA tTGA testing is unavailable, or when the result is weakly positive. Elevated serology levels suggest the need for a duodenal biopsy, performed via gastroscopy, to confirm the diagnosis through histological evidence of villous atrophy and crypt hyperplasia.

Treatment The cornerstone of treatment for coeliac disease is a strict gluten-free diet, which should lead to symptomatic improvement, normalisation of serology, and histological recovery. Patients newly diagnosed should be referred to a dietitian experienced in managing coeliac disease. Gluten-free staple foods are available on prescription in the UK. Additional treatments may include supplementation of vitamins and minerals if deficiencies are present.

Prognosis Adherence to a gluten-free diet generally results in an excellent prognosis, with improvement in symptoms, healing of the intestinal mucosa, and a decrease in the risk of complications, which can include osteoporosis, infertility, and small bowel cancer. Non-responsive or refractory coeliac disease, although rare, requires further investigation and management.

Annual Follow-up Guidelines suggest annual follow up should include the following tests:

• Coeliac serology — to assess adherence to a gluten-free diet.
• Full blood count and ferritin —for malabsorption/diet-related anaemia and iron deficiency; a thrombocytosis may suggest hyposplenism.
• Thyroid function tests —for associated autoimmune thyroid disease.
• Liver function tests —for associated autoimmune liver disease.
• Calcium, vitamin D, vitamin B12, and folate —for deficiency due to malabsorption and diet.