Coeliac disease Flashcards
What are the 4 things that becoming dysfunctional can lead to malabsorption?
- Problems with the pancreas secreting digestive enzymes
- Problems with the liver secreting bile acids
- Disruption to surface area modifications e.g. mucosal folds, villi, microvilli
- Disruption to the brush border enzymes
What are the common and the more rare symptoms of coeliac disease?
Common:
- Weight loss
- Failure to thrive
- Abdominal distension (enlargement/swelling)
- Diarrhoea
- Flatulence
Rare:
- Ostopenia/osteoporosis
- Abnormal liver function
- Nausea and vomitting
- Anaemia
- Constipation
What type of condition is coeliac disease?
An autoimmune disease of the small bowel
What presentation clearly distinguishes coeliac disease from other conditions like IBD?
In coeliac disease, the villi in the small intestine are flattened due to an abnormal sensitivity to gluten.
What are the clinical presentations of Coeliac disease?
- The villi in the small intestine are flattened due to an abnormal sensitivity to gluten.
- Malabsorption of nutrients due to damage to the small intestine.
- There should be a prompt clinical and histological improvement following the withdrawal of gluten from the diet.
What is the epidemiology of coeliac disease?
- About 1 in 100 of people in the UK have coeliac disease
- Only about 10-15% of patients who have coeliac have actually been diagnosed
- Increase in incidence in the last 25 years
- Slightly more common in females
- worldwide incidence- 0.05-1.2%
Which age group is most common for a coeliac diagnosis?
- Around 8-12 months of life, once the baby has just been weaned and introduced to gluten-containing foods
- Also in the 3rd-4th decade of life (30-40 years old)
What are the causes of coeliac disease?
- Has a genetic predisposition- >95% of patients with coeliac disease express abnormalities/variants in the HLA-DQ2 or HLA-DQ8 genes. up to 20% of first-degree relatives are affected.
HLA-DQ2 + DQ8 are cell-surface receptors on antigen-presenting cells that bind gliadin peptides tightly, activating t-lymphocytes and therefore, initiating an immune response. Gliadin is a protein found in gluten that coeliacs become intolerant to as the body sees it as a threat (so produces autoantibodies- inflammation in intestine = damage and flattening of the villi= unable to digest nutrients of food = malabsorption and associated symptoms) Undigested gliadin peptides induce innate and adaptive T cell-mediated immune responses. - Also requires consumption of glucose- have to have been exposed to gluten to get coeliac disease.
What health conditions can increase the risk of developing coeliac disease?
- Type 1 diabetes
- Down syndrome
- Turner’s syndrome
- Thyroid conditions
What is dermatitis herperiformis?
An intensely itchy rash that presents on the skin in the form of fluid-filled blisters as a result of gluten sensitivity.
- Most commonly forms on the limbs, trunk and scalp
Occurs due to the deposit of immunoglobulin A (IgA) antibodies in the skin
What is the treatment for dermatitis herpetiformis?
- Eating a strict gluten free diet is the only treatment for the underlying disease.
- Drug treatment with Dapsone (A sulfone- belongs to the ‘anti-invectives’ drug class) can provide immediate relief of symptoms. if dapsone is not appropriate, can use sulfapyridine but is less effective.
What causes the skin lesions and itchiness that presents in dermatitis herperiformis?
Occurs due to the deposit of immunoglobulin A (IgA) antibodies in the skin, which triggers further immunologic reactions resulting in lesion formation.
These IgA antibodies are directed against epidermal transglutaminase (an enzyme found in keratinocytes, corneocytes and hair follicles). The antibodies then travel to the skin where they bind with the epidermal transglutaminase protein. Gluten ingestion seems to trigger this reaction
Can coeliacs eat oats?
Oats do not contain gluten. They contain a similar protein called avenin and research has shown that most people with coeliac disease can safely eat avenin.
However, people with coeliac should avoid eating them unless they are labelled GF as they often become contaminated with gluten during manufacturing.
How is coeliac disease diagnosed?
- Looking at a patients symptoms- diarrhoea, malabsorption, weight loss, gas, abdominal pain etc
- Need a blood test- look at IgA antibodies and Endomysial antibodies
- Biopsy- take small samples of the lining of the small intestine
Patients should continue to eat gluten throughout the diagnosis process to prevent inaccurate results.
What are the complications that can be associated with undiagnosed coeliac disease and coeliac disease?
- Anaemia- iron or vitamin B12
- Osteoporosis
- Increased risk of malignancy- t-cell lymphoma of the small bowel- risk os increased by 3-6x or adenocarcinomas of the GIT e.g. pharynx, oesophagus or small bowel
- If untreated in pregnancy- can cause increased miscarriage risk and risk of baby with a congenital malformation
- If undiagnosed in childhood, can lead to short stature and malnutrition
