Myths vs facts: tTG IgA and allergy

tTG IgA (tissue transglutaminase antibodies) is a highly specific biomarker for celiac disease, an autoimmune enteropathy triggered by gluten. It is not an allergy test. Allergies (e.g., wheat allergy) are diagnosed via IgE antibodies or skin prick tests. A positive tTG IgA indicates active celiac disease but requires confirmatory duodenal biopsy. Consumer DNA or lab tests like MyBody-X may measure tTG IgA, but interpretation must be done by a physician. A negative result does not fully rule out celiac disease, especially in IgA deficiency. Evidence for tTG IgA diagnostic accuracy is strong (human-strong), based on numerous clinical studies and guidelines. Marketing claims that label tTG IgA as an 'allergy marker' are misleading. The distinction between autoimmune disease and allergy is clinically critical.