32 - Coeliac Disease Flashcards
celiac disease
- Autoimmune destruction of the villi in the small intestine
- Causes villus atrophy and flattening
- Leads to malabsorption and deficiencies in B12, iron, folate and weight loss
what kind of diarrhoea does celiac cause
osmotic
Macropscopic appearance
cobblestone and furry
goldstandard test for diagnosis?
histological
What are markers of the disease
• Disease is mediated by T/B cells and so antibodies produced are markers of the disease
What us the marsh criteria
used to judge severity of celiacs/stage
what are the 3 celiac antibodies and which is recommended
- Anti- TTG IgA (recommended)
- Anti - EMA IgA
- Anti- DGP IgA
What causes the malabsorption in celiacs
Loss of brush border ENZYMES
Why does diarrhoea occur and what kinds
malabs of carbs (osmotic), fats (steatorrhoea) and lactose intolerance (osmotic)
What mineral and vitamin deficiencies do you see in celiacs?
- iron deficiency is the most commonly seen in celiacs
- B12 and folate
- VITAMIN D (causing osteoporosis and osteopenia)
What skin condition do you see in 99% of celiacs?
Dermatitis herpetiformis
What are the 2 susceptibility genes?
HLA DQ2 and DQ8
What populations are more and less likely to develop Celiacs?
More common in northern european. NOT present in populations like japanese and chinese that do not have the HLA DQ2 gene
What likely causes the mucosal damage
Abnormal cellular and hormonal response to gliadin (component of gluten)
Pathology of celiacs?
• Villous atrophy and hypertrophy of crypts, intraepithelial lymphocytes
Pathophysiology?
- Loss of brush border enzymes
- Loss of stimulus of pancreatic and bile secretion (low CCK/secretin/enterokinases)
- Exudation of protein across denuded mucosa
What is anti-tissue transglulaminase antibodies (TTG)?
The antibodies against transglutaminase are not cytotoxic. They are a by-product of the inflammation caused by IMMUNE reaction
How does it present?
In childhood…
• Failure to thrive
• Diarrhea
• Irritable, poor apatite
• May present as iron deficiency, short stature/height, abnormal distension or screening
Adulthood…
• Was probably present but silent in childhood
• Abdominal bloating and discomfort
• Iron deficiency with or without anaemia (this especially in a young person with no other obvious causes)
• Also has folate deficiency makes diagnosis very likely
• Screening of relatives
When should celiac antibodies be requested?
- An unexpected iron deficiency anaemia
- Folate or B12 deficiency
- Fatigue
- IBS with predominant bloating
- Early onset or severe osteoporosis (not abs vit D)
- Type 1 diabetes
- Auto-immune thyroid disease
What is the initial test of celiac disease
- Initial test for celiac is a blood test for TTG antibody
What else may you test for?
- May also test family for HLA DQ2 and DQ8 to be used as negative predictive gene markers. Increase risk but not accurately BUT if you do not have these then likely it is not celiac
If an anti-body test is positive what is next?
- If the antibody test it positive it needs to be CONFIRMED by gastroscopy and duodenal biopsy showing villous atrophy (goldstandard)
Why can’t response to gluten free diet be diagnosis?
- NOT adequate to use response to a gluten free diet as evidence of celiacs as patients with IBS often improve with exclusion (FODMAP - polyols diet)
Only treatment for celiac is …
gluten free diet
What are they intolerant to
• Have intolerance to gluten proteins incl wheat (gliadin), rye (secalins) and barley (hordeins)
What 2 foods are harmless
corn and rice
what are they not sure about
oats
natural food?
• natural food sources apart from cereals are likely to be ok – fish, fruit, veg, meat
difficulties?
struggle to get fibre in diet - constipation
osteoporosis on GF diet
improves greatly as wel as high Ca diet
