How are tTG IgA and Allergie related?

tTG IgA (tissue transglutaminase IgA) is the primary serological marker for celiac disease, an autoimmune condition triggered by gluten. Celiac disease is often confused with allergy, but it is not a classic IgE-mediated allergy. However, the two can co-occur: individuals with celiac disease have a higher risk of other autoimmune disorders and also atopic conditions like hay fever or asthma. A positive tTG IgA test indicates an autoimmune reaction to gluten, not a wheat allergy. For allergy diagnosis, specific IgE antibodies to wheat components are required. Important: gluten must be consumed before testing tTG IgA to avoid false negatives. The evidence linking tTG IgA to allergy is mixed – there are epidemiological associations but no direct causal relationship. The test is well-validated for celiac disease (human-strong), but not for allergies.