Coeliac's Disease Flashcards
What is Coeliac’s Disease?
Gluten-sensitive enteropathy (not an allergy)
Why is Coeliac’s Disease NOT an allergy?
Not IgE mediated
Which genes make you genetically susceptible to Coeliac’s Disease?
HLAD2Q or HLADQ8
HLAD2Q/HLADQ8 are expressed in 20% of the population. Why don’t all of them have Coeliac’s disease?
Development requires a trigger - unknown (?enteric virus)
What is the pathophysiology of how Coeliac’s disease causes malabsorption?
T-cell activates epithelial cells - produce IL-5 during proliferation and IEL activation (both kill epithelial cells)
Flattened gut - decreased SA
Malabsoprtion
What is gliadin?
a peptide Gluten component
How does transamination of the gliadin peptide and activation of gliadin-specific T cells cause damage to intestinal epithelium?
Activation of plasma cells and other lymphocytes
release cytokines
Damage intestinal epithelium
Epithelial damage in Coeliac’s disease leads to?
Small intestinal villous atrophy
When you stop eating gluten ..?
Normal epithelium is restored
How does Coeliac’s Disease present?
Associated with dermatitis herpetiformis and intestinal lymphoma
What are investigations for Coeliac’s Disease?
anti-tTG
IgA (for screening)
Biopsy - gold-standard for diagnosis
How does the anti-tTG test work?
When gluten enters gut, epithelial cells are modulated by tTG
Gluten tTg complex is takes up by specific B cells and the concentrate antigens and present them
Protein broken up - present gluten part to CD4+
Gives signal to B cell to produce antibodies
What is the disadvantage of IgA screening?
IgA deficiencies can cause false negatives
What is the main cause of complications of Coeliac’s Disease?
Lack of compliance
What are possible complications of Coeliac’s Disease?
Osteoporosis, anaemia + other consequences of malnutrition
Increased incidence of MALT Lymphoma
