Coeliac Flashcards
What are non GI symptoms of coeliac disease?
Skin rash (dermatitis herpetoformis)
Lactose intolerance
Pancreatic insufficiency
What are complications of untreated coeliac?
Malignancy and osteoporosis
What is the aspect of wheat that is responsible for coeliac ?
Gliadin
What foods is gluten found in?
Wheat, barley and rye
What is the pathogenesis of coeliac?
Mucosal damage to the small bowel by triggering an immunological pathway that has an innate or adaptive immune response
What genotype is associated with coeliac disease?
HLA-DQ heterodimer in 95% of cases
HLA-DQ2 and HLA-DQ8
What are presenting symptoms of coeliac?
GI symptoms- weight loss
Malabsorption
Tiredness
Anaemia (iron deficiency anaemia and pernicious anaemia)
Osteoporosis
Dental enamel defects
Neurological symptoms (chronic inflammatory state)
Overweight can be common too
What blood tests would you be looking for to diagnose coeliac?
Positive for
tTG (tissue transglutaminase antibodies)
EMA (endomysial antibodies)
Immunoglobulin-A deficiency (can give a false positive result alone though)
What histology is looked for in coeliac diagnosis?
Mucosal parlour
Mosaic pattern
Miconodular appearance
Scalloping
Reduction in duodenal folds
Crypt hypertrophy
Villi atrophy
What is the classification system used for coeliac disease severity?
MARSH
Describe MARSH 0 classification of coeliac
Normal mucosa
Describe MARSH 1 classification of coeliac
Increased number of intraepithelial lymphocytes
Describe MARSH 2 classification of coeliac
Increased number of epithelial lymphocytes AND crypt atrophy
Describe MARSH 3 classification of coeliac
Partial or complete villous atrophy - classic coeliac lesion
Describe MARSH 4 classification of coeliac
Villous atrophy without increased epithelial lymphocytes. (VERY RARE and typically unresponsive to diet therapy)
What are long term consequences of untreated coeliac disease?
Malignancy: increased risk of lymphomas in small intestine (non-Hodgkin’s lymphoma)
Increased risk of small bowel adenocarcinoma
Osteoporosis (bone metabolism is disturbed)
Malnutrition (iron, folate, Vit D, Mg, Ca)
Calcium requirements for someone with coeliac?
1000-1500 mg/day.
Higher need than usual.
Associated comorbidities of coeliac?
Type 1 diabetes
Autoimmune disorders
Abnormal liver function
Dermatitis herpetiformis
What is HLA?
Human Leukocyte Antigen
In coeliac blood tests what values may be depleted?
Calcium
Magnesium
Total protein
Vitamin D
Albumin
Describe the 5 steps of Coeliac pathophysiology
- Gluten peptides are taken up by the epithelial cells
- Gluten peptides are disseminated by the enzyme ‘tissue transglutaminase’ in the sub epithelial layer
- They then fit the antigen binding motif on HLA-DQ2+ antigen presenting cell
- Recognition by CD4+ T-cells trigger a T-helper cell-1 immune response with generation of pro-inflammatory cytokines (IL-1; INF-gamma; TNF-alpha)
- Lymphocytes infiltrate the lamina propria and increase in intra-epithelial lymphocytes (IEL) causes crypt hyperplasia and villous atrophy
