Coeliac disease - clinical fact sheet and MCQ

Overview

Coeliac disease is a chronic, immune-mediated enteropathy precipitated by the ingestion of gluten in genetically susceptible individuals. It primarily affects the small intestine and is driven by an inappropriate immune response to gluten peptides, particularly gliadin, found in wheat, barley, and rye. The condition affects approximately 1% of the global population, although underdiagnosis remains a significant issue due to variable and often non-specific clinical manifestations.

Untreated coeliac disease can lead to intestinal damage from villous atrophy, nutrient malabsorption, anaemia, osteoporosis, infertility, and increased risk of intestinal lymphoma. Early diagnosis and adherence to a strict gluten-free diet (GFD) are essential to reduce complications and improve quality of life.

Diagnosis of coeliac disease

1. Clinical features and findings may be classical, non-classical, or silent:

• classical: diarrhoea, steatorrhoea, weight loss, malabsorption

• non-classical: abdominal pain, bloating, iron-deficiency anaemia, fatigue, osteopenia/osteoporosis, infertility, transaminitis

• silent: asymptomatic, often identified during work-up for associated conditions or through family screening

2. Commonly associated conditions:

• type 1 diabetes

• autoimmune thyroid disease

• first-degree relatives with coeliac disease

• Down syndrome, Turner syndrome

• inflammatory bowel disease

3. Initial investigations should include:

• serology: tissue transglutaminase IgA (tTG-IgA) and deaminated gliadin peptide (DGP) antibody tests

• these tests have >85% sensitivity and >90% specificity

• check total serum IgA simultaneously to exclude IgA deficiency (affects 2-3% of patients with coeliac disease, leading to a false negative result. If the IgA level is low, rely on IgG-based [DGP or TTG] serological markers)

• NOTE: check if the patient is on a gluten-free diet, as this can create false negative results

• HLA DQ2/DQ8

• high negative predictive value (>99%); can be a useful test to exclude coeliac disease

• however, poor positive predictive value, as they can be present in approximately 40% of patients in the general population

4. Red flags for coeliac disease

Refer urgently to a gastroenterologist if the coeliac serology is positive and/or if the patient has symptoms suggestive of small bowel malabsorption from villous atrophy such as:

• unintentional weight loss

• diarrhoea

• persistent vomiting

• iron deficiency anaemia

Such symptoms may indicate the need for further investigations, including endoscopy. 

A gastroscopy with duodenal biopsies is required for a definitive diagnosis of coeliac disease. The patient should be consuming 6-10 g of gluten daily (equivalent to approximately three to four slices of wheat bread or three to four Weet-bix) for at least 6 weeks prior to the gastroscopy. This is because a gluten-free diet can lead to false negative results. The patient should have at least four biopsies from the distal duodenum and at least two from the duodenal bulb.

5. Differential diagnoses

• Irritable bowel syndrome (IBS): often presents with abdominal pain, bloating, and altered bowel habits (diarrhoea, constipation or both), similar to coeliac disease. However, IBS does not cause malabsorption, weight loss, or nutrient deficiencies

• Inflammatory bowel disease (IBD): can mimic coeliac disease with diarrhoea, weight loss and anaemia. However, IBD may present with bloody diarrhoea, perianal disease (in Crohn’s), or systemic features such as fever

• Lactose intolerance: leads to bloating, diarrhoea and gas after dairy consumption but does not result in mucosal damage or nutrient deficiencies

• Small intestinal bacterial overgrowth (SIBO): can cause bloating, diarrhoea, and malabsorption. It may co-exist with or mimic coeliac disease

• Pancreatic insufficiency: leads to fat malabsorption, steatorrhoea, and weight loss. Unlike coeliac disease, it does not involve an immune-mediated enteropathy

• Microscopic colitis: presents with chronic watery diarrhoea, particularly in older adults. It is not associated with malabsorption

Management of coeliac disease

1. Dietary management

• Lifelong, strict adherence to a gluten-free diet is the cornerstone of management

• Refer to a dietitian experienced in coeliac disease for education, nutritional adequacy and label reading

• Gluten-containing grains to avoid include wheat, barley, rye and derivatives (eg spelt, semolina, triticale)

• Oats are often introduced cautiously; they must be certified gluten-free due to cross-contamination risk

2. Follow-up care

Monitor clinical response, adherence and nutritional status.

• Repeat coeliac serology at 6–12 months post-diagnosis and annually thereafter to assess dietary compliance

• coeliac serology usually normalises after at least 12 months of a gluten-free diet, but sometimes it can take up to 24-36 months. It is important to monitor the trend

• Assess for and treat nutritional deficiencies (iron, folate, B12, calcium, vitamin D)

• Perform bone mineral density testing at diagnosis

• consider repeat testing at least 2 years and, at most, 5 years thereafter depending on initial results, age, and compliance with a gluten-free diet

• Encourage pneumococcal vaccination - coeliac disease is associated with hyposplenism (abnormal spleen function), increasing infection risk

3. Screening of at-risk groups

• Recommend testing for asymptomatic first-degree relatives and individuals with associated autoimmune conditions - perform HLA-DQ2/8 AND coeliac serology testing

• A negative HLA-DQ2/8 test result has a strong negative predictive value (< 1% chance of coeliac disease)

• If HLA-DQ2/8 is positive but coeliac serology is negative, the individual is at risk for future disease - repeat serology is recommended if the individual becomes symptomatic. Can consider repeat serology every 3–5 years if initial testing is negative but risk remains elevated

4. Refractory coeliac disease - ongoing symptoms with villous atrophy despite strict adherence to a gluten-free diet

• Exclude dietary non-compliance and alternative diagnoses (eg IBS, microscopic colitis)

• Refer to a gastroenterologist for further evaluation, including consideration of type I or II refractory coeliac disease
  

References

Lebwohl B, Sanders DS, Green PHR. Coeliac disease. Lancet. 2018;391(10115):70–81. 

Leonard MM, Sapone A, Catassi C, Fasano A. Coeliac disease and non-coeliac gluten sensitivity: a review. JAMA. 2017;318(7):647–656. 

Rubio-Tapia A, Hill ID, Kelly CP, Calderwood AH, Murray JA. ACG clinical guidelines: Diagnosis and management of coeliac disease. Am J Gastroenterol. 2023;118(1):58–81.

Claim your CPD

After reading the clinical summary above and reviewing the references, complete the quiz to gain 30 minutes of EA CPD and 30 minutes of RP CPD. 

You can either self-report CPD to your CPD home, or Medcast will track your learning via your personal CPD Tracker and you can download and report these points once a year. See our CPD Tracker FAQ.  

Quiz

Please log in or sign up for a free Medcast account to access the case study questions and achieve the CPD credits.