Coeliac Disease Flashcards
What is coeliac disease?
Autoimmune type 4 hypersensitivity to gluten
IgA-tTG + VA
IgA-tTG = autoantibodies produced in response to gluten, target the tissue transglutaminase
VA = villi atrophy, damage and flattening of small intestinal villi and reducing surface area for nutrient absorption
Coeliac disease is a type _ hypersensitivity reaction to _____
4
gluten
In Coeliac disease, what are the autoantibodies produced in response to gluten?
IgA-tTG (tissue transglutaminase)
What are the 2 key features of Coeliac’s disease?
IgA-tTG autoantibodies in response to gluten
and
Villi atrophy
With villi atrophy in Coeliac’s diseae there is damage and flattening of ___ intestinal villi which reduces ____ ____ for nutrient _____
small intestinal
surface area
absorption
What is Coeliac’s often associated with?
Thyroid disorders and Addison’s disease
What are HLAs?
Human Leukocyte Antigens
Genes in MHCs that help code for proteins that differentiate between self and non-self
Which HLA makes people susceptible to Coeliac’s?
HLA DQ2 and DQ8
What are prolamins?
A group of plant storage proteins with high proline content
In Coeliac’s, what prolamins is in the gluten that primarily causes the hypersensitivity reaction?
alpha Gliadins
In Coeliac disease, alpha Gliadins in the gluten bind to ___ then interacts with ___
IgA
tTG
The binding of alpha Gliadin to IgA and interacting with tTG leads to increased ___ and the formation of IgA anti-___ and e______ antibodies
IgA
IgA anti-tTG
endomysial antibodies
Gluten is resistant to complete digestion in the small intestine, leading to the formation of…
gluten peptides
In the lining of the small intestine, gluten peptides present to what kind of cells?
T-cells
In Coeliac disease, when gluten peptides are presented to T-cells, the T-cells become activated and release…
inflammatory mediators including cytokines
The inflammatory mediators contribute to m_____ d____ and alterations in the structure of the small intestinal lining
mucosal damage
Chronic inflammation can lead to damage of the small intestinal ____ that aid nutrient absorption causing decreased surface area and potential malabsorption
villi
The malabsorption of nutrients due to damaged villi can lead to what symptoms?
Diarrhoea
Steatorrhea (excess fat in stool)
Weight loss
Abdominal pain
Fatigue
Nutritional deficiencies
Anemia (haematinic deficiency of either Fe, B12 or folate)
Osteopenia (decreased Ca absorption)
What is a symptom of Coeliac disease due to IgA skin deposition
Dermatitis herpetiformis (papular rash on knees)
What are 3 symptoms of anaemia associated with Coeliac’s?
Fatigue
Angular stomatitis (fry corners mouth)
Glossitis
How is Coeliac disease diagnosed?
Combination of serologic tests:
antibodies such as anti-tissue transglutaminase (anti-tTG) and anti-endomysial antibodies (EMA)
and Small intestinal/ duodenal biopsy:
Crypt hyperplasia, villous atrophy and epithelial lymphocyte infiltration
What is first line screening for Coeliac disease?
Serology:
anti-tTG
Increased total IgA
Second line = increased EMA (endomysial antibodies)
What is the gold standard diagnostic test for Coeliac disease?
Duodenal biopsy:
Crypt hyperplasia, villous atrophy and epithelial lymphocyte infiltration
How do you manage Coeliac disease?
Gluten free diet, strict and lifelong
Dietician review
Bone density assessment
Coeliac UK information
Prescription for gluten free foods
Immunisations
What are the main symptoms of Coeliac’s?
Diarrhoea, stomach aches and bloating
What are risks of not going on a gluten free diet?
Enteropathy associated T-cell lymphoma
Small bowel adenocarcinoma
Vitamin deficiencies
Osteoporosis
Hyposplenism
Malnutrition
Depression
Delayed puberty
Anaemia
Iron and folate deficiencies
What is dermatitis herpetiformis?
Chronic autoimmune condition that causes itchy bumps and blister on skin
Clusters of small, red.
Due to IgA antibodies (produced in response to gluten consumption) depositing in the skin. Neutrophilic infiltration.
Strongly associated with Coeliac Disease
What is tropical sprue?
Enteropathy associated with tropical travel that gives similar “sprue” biopsy as coeliac disease:
Crypt hyperplasia and villous atrophy
Often responds to antibiotics like tetracycline
