Coeliac Disease Flashcards
What is coeliac disease?
Coeliac disease is an autoimmune condition where exposure to gluten causes an immune reaction that creates inflammation in the small intestine. It usually develops in early childhood but can start at any age.
Briefly describe the pathophysiology of coeliac disease
In coeliac disease autoantibodies are created in response to exposure to gluten. These autoantibodies target the epithelial cells of the intestine and lead to inflammation. There are two antibodies to remember: anti-tissue transglutaminase (anti-TTG) and anti-endomysial (anti-EMA). These antibodies correlate with disease activity and will rise with more active disease and may disappear with effective treatment.
Inflammation affects the small bowel, particularly the jejunum. It causes atrophy of the intestinal villi. The intestinal cells have villi on them that help with absorbing nutrients from the food passing through the intestine. The inflammation causes malabsorption of nutrients and disease related symptoms.
What are the clinical features of coeliac disease?
Coeliac disease is often asymptomatic, so have a low threshold for testing for coeliac disease in patients where it is suspected. Symptoms can include:
- Failure to thrive in young children
- Diarrhoea
- Fatigue
- Weight loss
- Mouth ulcers
- Anaemia secondary to iron, B12 or folate deficiency
- Dermatitis herpetiformis is an itchy blistering skin rash that typically appears on the abdomen
Rarely coeliac disease can present with neurological symptoms:
- Peripheral neuropathy
- Cerebellar ataxia
- Epilepsy
What other condition is coeliac disease commonly linked to?
Type 1 diabetes.
What genetic mutations are associated with coeliac disease?
- HLA-DQ2 gene (90%)
- HLA-DQ8 gene
What auto-antibodies are present in coeliac disease?
- Tissue transglutaminase antibodies (anti-TTG)
- Endomysial antibodies (EMAs)
- Deaminated gliadin peptides antibodies (anti-DGPs)
What is the significance of anti-TTG and anti-EMA antibodies being IgA?
Anti-TTG and anti-EMA antibodies are IgA. Some patients have an IgA deficiency. When you test for these antibodies, it is important to test for total Immunoglobulin A levels because if total IgA is low the coeliac test will be negative even when they have the condition. In this circumstance you can test for the IgG version of the anti-TTG or anti-EMA antibodies or do an endoscopy with biopsies.
Briefly describe the diagnosis of coeliac disease
Investigations must be carried out whilst the patient remains on a diet containing gluten otherwise it may not be possible to detect the antibodies or inflammation in the bowel.
Check total immunoglobulin A levels to exclude IgA deficiency before checking for coeliac disease specific antibodies:
- Raised anti-TTG antibodies (first choice)
- Raised anti-endomysial antibodies
Endoscopy and intestinal biopsy show:
- “Crypt hypertrophy”
- “Villous atrophy”
What other medical conditions is coeliac disease associated with?
Coeliac disease is associated with many other conditions:
- Type 1 diabetes
- Thyroid disease
- Autoimmune hepatitis
- Primary biliary cirrhosis
- Primary sclerosing cholangitis
- Down’s syndrome
What complications are associated with untreater coeliac disease?
- Vitamin deficiency
- Anaemia
- Osteoporosis
- Ulcerative jejunitis
- Enteropathy-associated T-cell lymphoma (EATL) of the intestine
- Non-Hodgkin lymphoma (NHL)
- Small bowel adenocarcinoma (rare)
Briefly describe the management of coeliac disease
A lifelong gluten free diet is essentially curative. Relapse will occur on consuming gluten again. Checking coeliac antibodies can be helpful in monitoring the disease.
