Coeliac disease

Question 1

Coeliac disease

Answer 1

Inflammatory bowel disease.

Occurs as a result of auto-immune mediated response in the small intestine- to gliadin in gluten.

Causes malabsorption.

Question 2

Genetic abnormalities of coeliac disease

Answer 2

Mutation in genes:

• HLA-DQ2 [95%]
• HLA-DQ8 {5%]

Strong hereditary predisposition

Question 3

Prevalence of coeliac disease

Answer 3

Western Europeans and Americans
- Especially Irish and Scandinavian descent

High prevalence in:

• Down’s syndrome
• TI diabetes mellitus
• Autoimmune hepatitis (presents abnormal liver function tests)
• Thyroid gland abnormalities.

Question 4

Pathophysiology of coeliac disease [5]

Answer 4

1. Gliadin in wheat binds to tissue transglutaminase in small bowel mucosa.
2. Transglutaminase deaminates gliadin to release a negatively charge protein.
3. Triggers the release of IL-15
4. Stimulates the recruitment of NK and intraepithelial T cells
5. Inflammatory cells cause tissue destruction and villous atrophy.

Question 5

Pathological features of coeliac disease [4]

Answer 5

Villous atrophy
- Shortened and flattened out villi

Crypt hyperplasia
- Lengthened crypts to compensate for flattened villi.

Lymphocyte infiltration (chronic inflammation) in lamina propria

Increased transepithelial lymphocytes

Question 6

Presentation of coeliac disease

Answer 6

Abdominal distention

Failure to thrive and short stature in children.

Chronic diarrhea- steatorrhea

Weight loss + fatigue

Anaemia

Osteopenia and osteoporosis from Vit.D and calcium deficiency.

Question 7

Classification of coeliac disease

Answer 7

Classical:
- Shows malabsorption symptoms

Non-classical: symptoms outside GI tract

Sub-clinical:
- Detected with blood tests

Question 8

Symptoms outside GI from coeliac disease

Answer 8

Heartburn

Nausea

Recurrent miscarriage /infertility

Dermitis herpetiforms- skin rash

Question 9

Serological investigations for coeliac disease

Answer 9

Tissue transglutaminase antibodies (IgA) [TTGA]
- 98% sensitive, 96% specific

Endomysial IgA: detects autoantibody in endomysium

• Most specific (100%)
• Not as sensitive (90%)

Deaminated gliadin peptide- using IgA and IgG

Question 10

Investigations into coeliac disease

Answer 10

General: Full blood count, Liver function tests, renal function tests.

Duodenal biopsy

Genetic screening in children:
HLA-D2
HLA-D8

Serological tests

Question 11

Complications of coeliac disease

Answer 11

T-cell lymphoma

High risk of adenocarcinoma of small bowel and other organs

Dermatitis hepetiformis

Infertility and miscarraige