Coeliac disease

Question 1

What is coeliac disease?

Answer 1

Autoimmune disorder characterized by an intestinal hypersensitivity to gluten, causing chronic intestinal malabsorption
- Triggered by Gliadin (component of gluten)

Question 2

What causes coeliac disease?

Answer 2

• Due to sensitivity to the GLIADIN component of the cereal protein, gluten
• Exposure to gliadin triggers an immunological reaction in the small intestine leading to mucosal damage and loss of villi – lose ability to absorb hence diarrhoea and weight loss
• If gluten is removed from diet, villi can return and patient is asymptomatic – the damage is REVERSIBLE
• 10% risk of first-degree relatives being affected
• Clear genetic susceptibility associated with HLA-B8, HLA-DR3 and HLA-DQW2 haplotypes- these react to the glaidin and cause an immune response

Question 3

Summarise the epidemiology of coeliac disease

Answer 3

UK: 1/2000
West Ireland: 1/300
Rare in East-Asia

Question 4

What are the presenting symptoms of coeliac disease?

Answer 4

• May be asymptomatic
• Abdominal discomfort, pain and distention
• Bloating
• Steatorrhoea (pale bulky stool, with offensive smell and difficult to flush away)- due to malabsorption)
• Diarrhoea:
• Tiredness, malaise, weight loss (despite normal diet)
• Failure to ‘thrive’ in children
• Amenorrhoea in young adults

Question 5

What signs of coeliac disease can be found on physical examination?

Answer 5

1. Signs of anaemia (Iron-Deficiency) → coeliac disease leads to malabsorption symptoms such as vitamin deficiency: pallor
2. Signs of malnutrition:
   - Short stature
   - Abdominal distension
   - Wasted buttocks in children
   - Triceps skinfold thickness gives indication of fat stores
3. Signs of vitamin/mineral deficiencies: osteomalacia, easy bruising
4. Intense, itchy blisters on elbows, knees or buttocks (dermatitis herpetiformis) – intensely itchy papulovesicular lesions on the extensor surfaces of the skin (most common on elbows)

Question 6

What investigations are used to diagnose/ monitor coeliac disease?

Answer 6

1. 1st Line → IgA-tTG Antibodies (Immunoglobulin A - Tissue Transglutaminase) are elevated. (Also anti-endomysial antibodies and anti-gliadin antibodies elevated)
   - Patients must have eaten gluten for at least 6 weeks before they are tested or antibodies may be negative (same rule for endoscopy)
   - May get false negative if patient has IgA deficiency
   - Anti-TTG IgA is measured in the first instance but, if the patient is IgA deficient (2% of coeliac patients), anti-TTG IgG should be measured
2. Small Bowel Endoscopy + Histology (Biopsy) → essential & gold standard test to confirm the diagnosis.
   - Villous atrophy, crypt hyperplasia, increase in intraepithelial lymphocytes.
   - Should be performed in all patients following serology. (from Duodenum or Jejunum)
3. FBC → Low Hb (Anaemia) & Microcytic Hypochromic RBCs, low folate + B12.
   - Patients with iron deficiency anaemia should be screened for coeliac
4. Blood Smear → target cells and howell-jolly bodies (functional hyposplenism)
5. Skin Biopsy → if any lesions suggestive of Dermatitis Herpetiformis

Question 7

How is coeliac disease managed?

Answer 7

1. Gluten-free Diet (Abstain from products containing wheat, rye, barley)
2. Vitamin + Mineral supplementation
3. Pneumococcal Vaccine → patients with coeliac disease have a degree of functional hyposplenism (risk of pneumococcal sepsis)

Question 8

What complications may arise from coeliac disease?

Answer 8

1. Dermatitis Herpetiformis
2. Malignancy (enteropathy-associated T cell lymphoma)
3. Iron, folate and B12 deficiency
4. Osteomalacia
5. Ulcerative jejunoileitis
6. Increased risk of gastric/oesophageal/bladder/breast/brain malignancy
7. Bacterial overgrowth
8. Cerebellar ataxia (rarely)

Question 9

Summarise the prognosis for patients with coeliac disease

Answer 9

• FULL RECOVERY in most patients who strictly adhere to a gluten-free diet
• Symptoms usually resolve within weeks though histological changes may take longer
• Gluten-free diet must be followed for life

Question 10

What diagnosis would require further serological testing for coeliac disease?

Answer 10

NICE guidelines dictate that coeliac disease should be tested for in those with a new diagnosis of autoimmune thyroid disease or type 1 diabetes. This is owing to the underlying autoimmune element to these diseases