Coeliac Disease Flashcards
Pathology
Auto-antibodies are created in response to exposure to gluten that target the epithelial cells of the intestine and lead to inflammation. There are two antibodies: 1. anti-tissue transglutaminase (anti-TTG) 2. anti-endomysial (anti-EMA) 3. Deaminated gliadin peptides antibodies (anti-DGPs) Inflammation affects the small bowel, particularly the jejunum. It causes atrophy of the intestinal villi. The inflammation causes malabsorption of nutrients and the symptoms of the disease.
Common clinical features
Coeliac disease is often asymptomatic so have a low threshold for testing for coeliac disease in patients where it is suspected. - Failure to thrive in young children - Diarrhoea - Fatigue - Weight loss - Mouth ulcers - Anaemia secondary to iron, B12 or folate deficiency - DERMATITIS HERPETIFORMIS (an itchy blistering skin rash typically on the abdomen)
Genetic associations
HLA-DQ2 gene (90%) HLA-DQ8 gene
Diagnosis
Investigations must be carried out whilst the patient remains on a diet containing gluten Check total immunoglobulin A levels to exclude IgA deficiency before checking for coeliac disease specific antibodies: - Raised anti-TTG antibodies (first choice) - Raised anti-endomyseal antibodies Endoscopy and intestinal biopsy show: - “Crypt hypertrophy” - “Villous atrophy”
Why do you need to test for IgA also?
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 because they have an IgA deficiency then the coeliac test will be negative even when they have coeliacs. In this circumstance, you can test for the IgG version of anti-TTG or anti-EMA antibodies or simply do an endoscopy with biopsies.
Associated Conditions
Type 1 Diabetes Thyroid disease Autoimmune hepatitis Primary biliary cirrhosis Primary sclerosing cholangitis
Complications of untreated disease
Vitamin deficiency
Anaemia
Osteoporosis (so DEXA scan)
Ulcerative jejunitis
Enteropathy-associated T-cell lymphoma (EATL) of the intestine (mall bowel)
Non-Hodgkin lymphoma (NHL)
Small bowel adenocarcinoma (rare)
Hyposplenism (and therefore a susceptibility to encapsulated organisms)
Management
Lifelong gluten free diet is essentially curative. Relapse will occur on consuming gluten again. Checking coeliac antibodies can be helpful in monitoring the disease.
What is this?
Dermatitis Herpetiformis
Blistering rash
Associated with Coeliac Disease
Other asociated
