Coeliac disease

Coeliac disease is also known as gluten-sensitive enteropathy and nontropical sprue which affects approximately one in 70 Australians. Coeliac disease usually present between the ages of 10 and 40 years. Children with life-threatening malabsorption from coeliac disease are rarer nowadays due to longer periods of breast-feeding and the later introduction of gluten in the infant diet. Foods thats contain gluten caused damage to lining of small intestine and impair absorption of nutrients. This leads to malnutrition, osteoporosis, depression, infertility, iron deficiency anaemia and small increased risk of lymphoma of bowel. It also can cause skin rash such as dermatitis herpertiformis. Coeliac disease is closely associated with type 1 diabetes mellitus and polyglandular autoimmune syndrome type III (autoimmune thyroiditis).

Foods that contain gluten are as follows:

  • Barley
  • Rye
  • Oats - consumption should be limited to 50 to 60g/day in mild disease or those in remission. Patients with severe coeliac disease should avoid oats altogether
  • Wheat

 Many patients with coeliac disease can have secondary lactose intolerance.

Coeliac disease is classified into different types:

  • Classic disease - Patients have villous atrophy; symptoms of malabsorption such as steatorrhoea, weight loss and signs of nutrient or vitamin deficiency. Recovery of the intestinal mucosal linings and symptoms usually take within a few weeks to months after withdrawal of gluten-containing food. Patients will usually have positive transglutaminase Ig A and anti-gliadin antibodies.
  • Atypical coeliac disease - Patients have minor gastrointestinal complaints. They can have anaemia, dental enamel defects, osteoporosis, arthritis, abnormal liver function test, neurological symptoms or infertility. Most of these patients will have damage to intestinal mucosal linings and positive antibodies.
  • Asymptomatic (silent) coeliac disease - Patients usually incidentally found to have positive transglutaminase Ig A and anti-gliadin antibodies when they had screening blood tests. Patients do not have any clinical symptoms except minor symptom such as fatigue.
  • Latent coeliac disease - Some patients have normal intestinal mucosal linings and minor symptoms or no symptoms while on gluten containing diet.

Clinical features:

  • Gastrointestinal manifestations - Patients may present with diarrhoea with bulky, foul-smelling, floating stools due to steatorrhoea and flatulence. These may cause growth failure in children, weight loss, severe anaemia, neurological disorders from deficiencies of B vitamins, and osteopenia from deficiency of vitamin D and calcium.
  • Iron deficiency - Coeliac disease is a common cause of iron deficiency anaemia.
  • Bone disease - Patients with coeliac disease has significantly decreased in bone mineral density in the lumbar spine and femoral neck leading to osteopenia or osteoporosis. Patients may have secondary hyperparathyroidism due to vitamin D deficiency.
  • Risk of increasing bowel lymphoma and shorten lifespan.
  • Skin rash - Dermatitis herpetiformis is multiple intensely itchy papules and vesciles usually affecting the elbows, back of forearms, knees, scalp, back and buttocks. This rash will clear up after withdrawal of food containing gluten.
  • Diabetes mellitus - Patients with coeliac disease should be screened to see if they have type 1 diabetes mellitus. This is due to autoimmune disease which cross related to coeliac disease.
  • Ig A deficiency - There is established association between Ig A deficiency and coeliac disease.
  • Liver disease - Patients with coeliac disease usually have mildly abnormal liver function test. However, this has been found to be associated with primary biliary cirrhosis, autoimmune hepatitis, primary sclerosis cholangitis or congenital liver fibrosis.
  • Menstrual and fertility issues - Women with untreated coeliac disease may have later menarche, earlier menopause, secondary amenorrhoea, recurrent miscarriage, infertility, preterm delivery and low birth weight. 

Diagnosis:

  • Blood test with coeliac serology should be the initial test for individuals over the age of 2 years. When there is a high probability of coeliac disease, total IgA should be measured. This blood test is best to be done when patient is on gluten diet. 
  • Small bowel biopsy - Patient with positive coeliac serology should undergo gastroscopy with small bowel biopsy to confirm the diagnosis of coeliac disease.
  • HLA DQ2/DQ8 - Patients with suspected coeliac disease but on gluten free diet with negative coeliac serology should undergo blood test for HLA DQ2/DQ8 to determine if the patient is genetically susceptible to coeliac disease. If the HLA DQ2/DQ8 is negative, coeliac disease is most likely to be excluded.

Management:

  • Foods containing wheat, rye and barley should be avoided.
  • Oats should be introduced into the diet with caution, and monitored for adverse reactions. Oat consumpation should be limited to 50 to 60 g/day in patients with mild disease or those in remission after strict gluten free diet. The patients can then be monitored with blood test for coeliac serology to check for recurrence. Patients with severe disease should avoid oats altogether.
  • For patients who are not responding to gluten free diet, other disorders such as refactory sprue or bowel disease will need to be need to be ruled out.