What role does tTG IgA play in allergy?

tTG IgA (tissue transglutaminase IgA) is not an allergy marker; it is the primary serological test for celiac disease, an autoimmune condition triggered by gluten. While untreated celiac disease can increase intestinal permeability and potentially contribute to food allergies, tTG IgA itself plays no role in the IgE-mediated allergic cascade. A positive tTG IgA test must be confirmed by duodenal biopsy. Confusion between celiac disease and allergy is common, so a specialist (gastroenterology/allergology) should interpret results. Evidence is strong for celiac disease, not for allergy.