Coeliac Disease



Coeliac disease is an autoimmune condition where exposure to gluten causes an autoimmune reaction that causes inflammation in the small bowel. It usually develops in early childhood but can start at any age.

In coeliac disease, 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 to remember: anti-tissue transglutaminase (anti-TTG) and anti-endomysial (anti-EMA). These antibodies relate to 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 the symptoms of the disease.

Presentation

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)

 

Rarely coeliac disease can present with neurological symptoms:

  • Peripheral neuropathy
  • Cerebellar ataxia
  • Epilepsy

 

TOM TIP: Remember for your exams that we test all new cases of type 1 diabetes even if they don’t have symptoms as the conditions are often linked.

 

Genetic Associations

  • HLA-DQ2 gene (90%)
  • HLA-DQ8 gene

 

Auto-antibodies

  • Tissue transglutaminase antibodies (anti-TTG)
  • Endomysial antibodies (EMAs)
  • Deaminated gliadin peptides antibodies (anti-DGPs)

 

TOM TIP: 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.

 

Diagnosis

Investigations must be carried out whilst the patient remains on a diet containing gluten otherwise it may not be possible to detect 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

 

Associations

Coeliac disease is associated with many other autoimmune conditions:

  • Type 1 Diabetes
  • Thyroid disease
  • Autoimmune hepatitis
  • Primary biliary cirrhosis
  • Primary sclerosing cholangitis

 

Complications of Untreated 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)

 

Treatment

Lifelong gluten-free diet is essentially curative. Relapse will occur on consuming gluten again. Checking coeliac antibodies can be helpful in monitoring the disease.

 

Last updated February 2019
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