Coeliac Disease Flashcards
what is coeliac disease?
common, chronic, immune-mdiated enteropathy triggered/maintained by gluten ingestion in genetically predisposed individuals
what symptoms are common in coeliac disease?
intestinal inflammation
intraepithelial lymphocytosis (severe infiltration)
villous atrophy/crypt hyperplasia
describe the 2 types of coeliac disease
silent coeliac - manifest mucosal lesion
latent coeliac - normal mucosa (genetic susceptibility)
what is gluten?
subtype of prolamin with high proline AA content
storage proteins in cereal grains
made of gliadin and glutenin
why does gluten cause digestion problems?
high proline content makes gluten resistant to intestinal protease
undigested peptides disturb microbiota
high glutamine content can be immunogenic (substrate for TTG which deaminates it to glutamate, bound by APCs)
what makes someone genetically predisposed to coeliac disease?
HLA DQ2/8 is necessary but not sufficient
must have gluten specific T cell receptors
(60% not related to HLA)
explain the pathophysiology of coeliac disease
ingested gluten digested by intestinal proteases, insufficient digestion presents gluten peptides which are deaminated by transglutatamase and presented to APCs
HLA DQ2/8 APCs allow B/T cells to produce anti-gluten antibodies inducing cytokine cascade (Il/IFNy) to begin anti-inflammatory process
who should be tested for coeliac disease?
- GI manifestations related to malabsorption
- IBS/constipations
- dermatitis herpetiformis
- iron deficiency/anaemia
- many more
how can coeliac disease be tested?
must be on gluten containing diet
- bayesian probability/prevalence
- IgA deficiency
- duodenal biopsy (histology/immunohistochemistry)
- HLA
- small bowel imagine
- response to gluten free diet
how can coeliac disease be tested?
must be on gluten containing diet
- bayesian probability/prevalence
- IgA deficiency
- duodenal biopsy (histology/immunohistochemistry)
- HLA
- small bowel imagine
- response to gluten free diet
what serology tests are done for coeliac disease?
IgA anti-gliadin
IgA anti-endomysial
anti-tTG
what are the treatment options for coeliac disease?
gluten free diet (<20ppm)
nutritional assessment
bone health (FRAX/DEXA)
vaccination (pneumo/meningococcus)
what are the complications of CD?
functional hyposplenism
infection risk (pneumo/meningococcus)
osteoporosis (25%)
dermatitis herpetiformis
increased cancer (non-hodgkins lymphoma)
IgA deficiency
EATL
how is CD monitored?
serology - should return to normal eventually
re-biopsy
symptoms not necessarily a guide
why might CD not be improving?
still consuming gluten
infection (giardiasis/HIV)
SIBO
medication induced
refractory CD
