Coeliac Disease

Question 1

What is coeliac disease?

Answer 1

• = a gluten enteropathy; T cell mediated reaction to gliadin

Question 2

Pathophys of coeliac disease

Answer 2

• Gluten peptides, e.g. gliadin, are deamidated by free tissue transglutaminase (tTG)
• These deamidated peptides bind to HLA DQ2 or DQ8, present in most CD patients (80-90%)
• This activates cytotoxic T cells -> Abs produced -> epithelial damage

Question 3

Histopath features of coeliac disease

Answer 3

• villous atrophy and crypt hyperplasia
• increased number of plasma cells and lymphocytes in lamina propria
• increased intraepithelial lymphocytes
• Most severe in proximal bowel

Question 4

What is the relationship between HLA DQ2/DQ8 and coeliac disease?

Answer 4

• 30-40% caucasians carry DQ2/DQ8, but <3% of these develop CD (so there must be an interplay for pathophys)

Question 5

What other conditions can coeliac disease be associated with?

Answer 5

○ Dermatitis herpetiformis
○ Epilepsy 
○ Myopathy 
○ Depression
○ Paranoia
○ Infertility 
○ Bone fractures /metabolic bone disease

• Thyroid disease
• T1DM
• Addison’s

Question 6

What vitamin deficiencies can you develop with coeliac disease?

Answer 6

iron, Ca, folic acid > vitamin B12 (bc of proximal bowel)

Question 7

Dx by?

Answer 7

• Usually have small bowel (duodenal) biopsy for Dx:
  • 1st biopsy - evidence of villous atrophy with gluten diet
  • Follow up biopsy - evidence of villous improvement without gluten
• Adequate gluten needed for 6 weeks

Question 8

Aside from the GS Dx Ix, what other Ix could you do for coeliac?

Answer 8

• FBE and blood smear: microcytic anaemia (rare to have folate and vitamin B12 deficiencies leading to macrocytic anaemia)
• Serology:
  • IgA-tTG and anti-gliadin Abs
    ○ High specificity and sensitivity
  • EMA (endomysial antibody)
  • IgA deficient pts have false negative - so measure serum IgA concomitantly (via serum protein electrophoresis)

Question 9

Future risk with coeliac disease of…?

Answer 9

• Intestinal lymphoma

* Carcinoma e.g. small bowel and colon

Question 10

In which foods is gluten found?

Answer 10

BROW:

• Barley
• Rye
• Oats (controversial): oats allowed if not contaminated by other grains
• Wheat