Dr. Mohsin Rashid MD, MEd, FRCP(C)
Professor of Paediatrics, Gastroenterology & Nutrition – Dalhousie University
Celiac disease (CD) is a permanent intolerance to gluten (a protein present in wheat, rye and barley), which causes damage to the small intestinal mucosa by an autoimmune mechanism in genetically susceptible individuals. Autoantibodies such a tissue transglutaminase antibody (TTG), endomysial antibody (EMA) and deamidated gliadin peptide (DGP) are produced in the body and form the basis of serological tests used for screening. The diagnosis of CD is confirmed by small intestinal biopsy and treatment consists of a strict gluten-free diet for life.
Celiac disease is one of the most common chronic gastrointestinal disorders. It is estimated that 1% of the population is affected by CD, but majority of these individuals remain undiagnosed. Celiac disease was thought to be a rare malabsorptive disorder of infancy and childhood. However, it is now considered to be a common, multi-system disorder that can present at any age when gluten is present in the diet.
Awareness of CD amongst health professionals remains poor. Two large surveys from Canada have demonstrated that the mean duration of symptoms before diagnosis of CD in adults is about 12 years.
Celiac disease has a broad clinical spectrum. In classical (typical) CD, the patient presents with features of malabsorption such as diarrhea, steatorrhea, and weight loss or growth failure. In non-classical (atypical) CD, signs and symptoms of malabsorption are absent and patient may have other intestinal and/or extra-intestinal symptoms. Majority of patients with CD now present with non-classical symptoms. Clinical indications for screening for CD include the following;
- Chronic diarrhea
- Autoimmune thyroid disease
- Unexplained weight loss
- Type 1 diabetes
- Abdominal pain/bloating
- Autoimmune liver disease
- Abdominal distension
- Down syndrome
- Irritable bowel syndrome
- Turner syndrome
- Chronic fatigue
- First-degree relatives
- Idiopathic elevation of transaminases
- Recurrent aphthous stomatitis
- Dental enamel defects
- Iron deficiency anemia
- Chronic constipation
- Peripheral neuropathy
- Dermatitis herpetiformis
- Selective IgA deficiency
- Additional features in children:
- Delayed puberty
- Growth failure
- Short stature
- Recurrent vomiting
The currently recommended test to screen for CD is IgA-tissue transglutaminase antibody (TTG). IgA deficiency is common in CD and hence total serum IgA level must also be measured. Patients with a positive test should be referred for endoscopic small intestinal biopsy to confirm the diagnosis. A gluten-free diet should NOT be started before an intestinal biopsy is performed, as it will affect the interpretation of the biopsy and make confirmation of the diagnosis difficult.
A timely diagnosis of CD will help alleviate suffering, prevent nutritional deficiencies and may also reduce the risk of developing certain cancers and other autoimmune disorders.