coeliac disease Flashcards
(35 cards)
Coeliac Disease: Definition
- Autoimmune condition
- genetic
- causes villus atrophy and crypt hypertrophy when gluten (gliadin) is ingested
- bc autoantibodies are created in response
name the differences which occurs to the small intestine
villous atrophy
crypt hyperplasia
genotypes
HLA-DQ2
HLA-DQ8
autoantibodies
Anti-tissue transglutaminase antibodies (anti-TTG)
Anti-endomysial antibodies (anti-EMA)
Anti-deamidated gliadin peptide antibodies (anti-DGP)
Coeliac Disease: Complications
dermatitis herpeiformis
- IgA mediated
- blistering, itchy disease of skin
enteropathy-associated T cell lymphoma
- should be suspected in patients with unresponsive coeliac disease
coeliac crisis
Coeliac Disease: Aetiology
Caused due to an intolerance to proteins called prolamins
Genetic:
Strong association with human leukocyte antigens
HLA-DQ2 - present in 95% of cases
HLA-DQ8 present in 5%
Genetic testing has a high negative predictive value - those without the gene are unlikely to have the disease
coeliac crisis presentation and treatment
- presentation: unexplained diahrrhea, severe malabsorption and electrolyte imbalances
- treatment - rehydration with electrolytes and corticosteroids to reduce inflammation
Coeliac Disease: DDx
cow milk, food sensitive enteropathies
chrones disease
colitis
GIT lymphoma
whipples disease
IBS
Coeliac Disease: Epidemiology
Common in northern Europeans
Coeliac Disease: Investigations
To get a diagnosis - gluten challenge: 10g gluten day for 4-6 weeks:
- IgA anti-tissue transglutaminase - high while eating gluten
gold standard:
endoscopy with duodenal biopsy before and after eating gluten:
Raised intraepithelial lymphocytes
Coeliac Disease: Management
gluten free diet
bone density:
- dexa scan
- frax score
immunisations - more suseptable to infections
calcium and vitamin D suppliments
Coeliac Disease: Key Presentations
Diarrhoea, Weightless and Anaemia
Coeliac Disease: Pathophysiology
- gluten converted to gliadin
- binds to IgA forming complex
- binds to transferrin which allows the complex to cross from lumen to lamina propria
- reacts with tissue transglutaminase which removes an amide from gliadin
- this is then presented to the Thelper cells via HLA molecule DQ2/DQ8 - phagocytosed
- Thelper then secrete pro-inflammatory cytokines
- causes mass inflammation
- damage to enterocytes
lead to formation of:
- anti-gliadin
- anti-TGi
- anti-endomysim antibody
pathology - damage to enterocytes causes which 3 features
- villus atrophy
- crypt hyperplasia
- inflammatory infiltration
Coeliac Disease: Risk Factors
Fx History
Type 1 diabetes
Genetic (HLA)
Autoimmune thyroid disease
IgA defiency
Inflammatory Bowel Disease
Coeliac Disease: Signs
- mouth ulcering
- muscle wasting
- anaemia - malabsorption or iron and folate
- osteoporosis - malabsorption of Ca and vitD
- dermatitis herpetiformis
- failure to thrive
Coeliac Disease: Symptoms
- malabsoption - anaemia
- iron deficiency
- weight loss
- tired all the time
- abdominal bloating
- diarrhoea
- dermatitis herpesformis
Coeliac Disease: What is gluten made up of?
Complex mix of: gliadin and glutenin
Conditions associated with coeliac disease?
“I Don’t Take Apples, I Take Oranges”
*IgA deficiency
*Down’s syndrome
*Turner’s syndrome
*Autoimmune thyroid disease and autoimmune hepatitis
*IgA nephropathy
*Type 1 diabetes mellitus
*Other autoimmune conditions (e.g. Sjögren’s, myasthenia gravis, Addison’s disease)
How do you get a diagnosis?
To get a diagnosis - gluten challenge: 10g gluten day for 4-6 weeks
The first-line blood tests are:
- Total immunoglobulin A levels (to exclude IgA deficiency)
- Anti-tissue transglutaminase antibodies (anti-TTG)
second line:
anti-EMA
Why do people with coeliac disease recieve the pneumococcal vaccine?
Due to Hyposplenism
Dermatitis herpetiformis
- itchy, blistering skin rash
- typically affecting the knees, elbows and natal cleft
what might be seen on blood slide
- howell-jolly bodies
- hypersegmented anaemia
(megaloblastic anaemia)
most sensitive test overall
duodenal biopsy bc it shows the differences in the muscosa even in those with mild disease
