Celiac disease: what you need to know

Celiac disease is an autoimmune disease of the bowel. It is caused by the small intestine’s abnormal response to gluten (wheat, rye, barley, etc.). The autoimmune response causes inflammation in the bowel wall, resulting in a much smaller surface area for absorbing nutrients. In the long term, the bowel loses its ability to absorb certain essential nutrients, including vitamins and minerals, leading to malnutrition even with an adequate diet. [1] Celiac disease affects approximately 1% of Canadians, and most cases are undiagnosed. [2]

Celiac disease is genetic in combination with triggers. Over 95% of individuals who are gluten intolerant have one or two genes known as HLA -DQ2 and HLA DQ-8. The risk of developing celiac disease is higher in their first-degree relatives (parents, brothers, sisters, children) or in individuals with another autoimmune disease (type 1 diabetes, Hashimoto’s thyroiditis, etc.). [3]

However, there are non-genetic triggers that are poorly defined so far: 20% of individuals with HLA-DQ2 and HLA-DQ8 genes do not have gluten intolerance. Causes may include early introduction of gluten into newborns’ diets, imbalanced microbiota (microorganisms in the gut), surgery, pregnancy, or a viral infection and even severe stress. [4]

The most common symptoms in adults occur after gluten absorption [5]:

• Abdominal pain
• Bloating/constipation
• Diarrhea/constipation
• Nausea/vomiting
• Fatigue and headache

Other symptoms are gradual and long-term:

• Anemia (due to lack of iron) 
• Mouth ulcers and swollen tongue
• Bone weakness (osteoporosis or osteomalacia)
• Sensations of tingling (numbness) in arms and legs
• Painful rash (blisters) with itching (dermatitis herpetiformis)
• Joint pain
• Swollen legs (fluid retention)
• Difficulty getting pregnant

The term celiac disease refers to people with confirmed signs of damaged gut mucosa and signs of malnutrition. The tests used for making a diagnosis are:

There are many antibodies (immunoglobulins) that may be produced in celiac disease. The most helpful ones are anti-transglutaminase (anti-tTG) immunoglobulin levels: results are positive in the vast majority of celiac patients, and their levels are a way of monitoring diet effectiveness.

Some celiac patients have an overall reduction in IgA, which sometimes hides the presence of anti-tTG IgA. In cases of abnormally low IgA levels (always measured at the same time), anti-TG IgG testing is done instead of anti-TG IgA testing.

A gluten-free diet can quickly result in a false negative result. Therefore, it is important to maintain a diet containing gluten (the equivalent of 4 slices of bread daily) for the 4–6 weeks prior to the test.

HLA-DQ2 and DQ8 gene detection may be used in some situations in which maintaining a preparatory high-gluten diet is not appropriate (children, severe reactions, etc.). If both genes are absent, it is highly unlikely that the person has celiac disease.

Positive screening for celiac disease may be validated by symptoms disappearing when following a low-gluten diet. However, a definitive diagnosis must be confirmed by microscopic analysis of a small intestine wall biopsy taken by endoscopy or by video capsule (without a biopsy). [5]

Since there is a strong hereditary component to celiac disease, it is important to screen immediate family members.

In the absence of specific antibodies (anti-tTG IgA) and with no abnormalities in the gut mucosa (such as villous atrophy) visible under a microscope, non-celiac gluten sensitivity (NCGS) may also be suspected.

Thousands of people (1–3% of the population) experience unpleasant gastro symptoms with no bowel lesions or signs of malnutrition. Their symptoms taper off or go away when gluten (or most gluten) is removed from their diet. Such people have non-celiac gluten sensitivity (NCGS), a condition that is difficult to diagnose because there is no lab test to confirm it.

The most common complications of celiac disease come from malabsorption of nutrients:

• Reproductive difficulties (infertility, repeated miscarriages, missing periods (amenorrhea), and early menopause)
• Liver damage (autoimmune hepatitis)
• Kidney damage (Berger’s disease, which may lead to kidney failure)
• Infections
• Other autoimmune diseases (type 1 diabetes)
• Some cancers (bowel lymphomas, cancer of the small intestine)
• Neurological diseases (peripheral neuropathy, convulsions)
• Psychiatric diseases (anxiety, depression, mood, and attention disorders)

Some complications are primarily found in children [4]:

• Delayed growth
• Dental enamel damage
• Small size
• Delayed puberty
• Neurological symptoms (irritability, ADHD, learning difficulties, lack of muscle coordination, and convulsions)

Chez la majorité des enfants, une diète sans gluten permet le rétablissement de l’intestin grêle en 3 à 6 mois. Chez les adultes, une guérison complète peut prendre quelques années.

We offer specialized screening services that can help your doctor diagnose digestive disorders and diseases, including celiac disease.

• Anti-transglutaminase (IgA) serological test
• HLA-DQ2 and DQ8 genetic tests

Do you have a doctor's prescription on hand for one of these tests? Book an appointment online or contact Biron Health Group’s customer service at 1 833 590-2712.