In all cases, it is recommended that in the case of suspected celiac disease, carry out a serological test to detect the presence of specific antibodies with tTG IgA (anti-tissue transglutaminase IgA). This test is sufficiently reliable, both for children and for adults. Never start a gluten-free diet at this point.
A positive serology should be followed by a referral to a specialist. The specialist can either confirm or exclude celiac disease by additional techniques (endoscopy with duodenal biopsies and possibly additional blood analysis (EMA = anti-endomysium antibody and / or HLA-DQ2 + HLA-DQ8 = antigens of human leukocytes).
In case of anti-tTG IgA negative serology, it is necessary to take into account the possibility of false negatives (5%). The doctor may consider having the total IgA tested in the blood. If this result is abnormal, a tTG IgG antibody test is prescribed. The sensitivity and specificity of this test is very high in the event of total or almost total villous atrophy (degradation of the villi in the small intestine). But in the case of lower grade conditions, the result of this analysis is less reliable.
It is only after confirmation of these various stages that the gluten-free diet for life must be prescribed by the doctor. Adequate personal and relevant explanations on the diet will be developed by a dietitian qualified in the field of celiac disease.
View diagram in the appendix for a better understanding.
