Coeliac disease is an autoimmune condition in which there is increased immunological responsiveness to ingested gluten resulting in villous atrophy and malabsorption.
Gluten is found in wheat, barley and rye.
Signs and symptoms of coeliac disease:
- Abdominal pain
- Weight loss
- Diarrhoea
- Steatorrhoea
- Bloating
- Nausea and vomiting
- Fatigue
- Unexplained iron deficiency or other anaemia
Conditions associated with coeliac disease include:
- Dermatitis herpetiformis (up to 90% of patients with dermatitis herpetiformis will have coeliac disease)
- IBS
- Type 1 diabetes
- Multiple autoimmune conditions, including autoimmune thyroid disease and autoimmune liver disease
Genetics
- There is 75% concordance in monozygotic twins.
- HLA DQ2 is associated with most cases of coeliac disease.
- HLA DQ8 is present in a minority of cases
Diagnosis
- Serology
- Need to have a gluten-containing diet for 6 weeks prior to testing
- IgA tissue transglutaminase (tTGA) is the first choice test (sensitivity 95%)
- IgA endomysial antibodies (EMA) is recommended if tTGA result is equivocal
- If tTGA is negative, test for IgA deficiency (which is associated with coeliac disease) and if present do IgG tTGA
- If a positive serology result is obtained, or it is negative but there is an ongoing clinical suspicion of coeliac disease, an intestinal biopsy should be performed
- Intestinal biopsy
- Small bowel villous atrophy
- Crypt hyperplasia
- Thickening of basement membrane
- Decreased numbers of goblet cells
- Increased intraepithelial lymphocytes
- NB IgA or IgG anti-gliadin antibody tests are NOT recommended by NICE
Complications of coeliac disease
- Small bowel lymphoma (50x more common, but low absolute risk)
- Osteoporosis
- Reduced fertility
- Functional hyposplenism
Management
Gluten-free diet
Small print gem: false positive tTGA results may occur in chronic liver disease, type 1 diabetes, myeloma and monoclonal gamopathy.
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