Coeliac disease (gluten intolerance) is defined as a typical mucosal change of the small intestine, caused by gluten in the diet. In ”classical” coeliac disease the patient has diarrhea, weight loss and various defi ciencies due to inadequate nutrient uptake.
Indications: Suspicion of coeliac disease or dermatitis herpetiformis. Control of effect of glutenfree diet.
Today milder forms of the disease are often diagnosed with less serious symptoms, e.g. abdominal pains, stomach gas, tiredness, anemia and osteoporosis. About 1% of the population is considered to suffer from the disease and it often occurs together with other autoimmune diseases, such as diabetes, autoimmune thyroid disease and psoriasis. About 2-5% of the patients may have IgA defi ciency. If this is the case, tests for IgG anti-tTG and IgG anti-gliadin should be performed. In small children anti-gliadin may be the only antibody. The fi nal diagnosis is made through small intestine biopsy.
Coeliac disease has strong genetic links to HLA-DQ2 and HLA-DQ8. If both HLA markers are negative, the diagnosis can almost be excluded. Anti-tTG and anti-endomysium are considered to have almost 100% sensitivity and specificity in clinical coeliac disease. The level of the antibodies often correlates with mucosal change and therefore a lower sensitivity is observed early in the disease and when there are minor changes of the small intestine. This means that repeated testing has to be done when screening early in the disease. The antibodies normally disappear with gluten-free diet.