Can tTG IgA help with allergy?

The question 'Can tTG IgA help with allergy?' reflects a common confusion. tTG IgA (tissue transglutaminase antibodies) is a well-established biomarker for celiac disease, an autoimmune condition triggered by gluten, not for allergies (e.g., pollen, food, or insect venom). Allergies are diagnosed via specific IgE or skin prick tests. However, tTG IgA may be relevant if allergy-like symptoms (diarrhea, bloating, fatigue) are actually due to undiagnosed celiac disease. The evidence for tTG IgA in celiac disease is strong (human-strong), but there is no evidence supporting its use for allergy diagnosis. False positives can occur, and a positive result should be confirmed by duodenal biopsy. In summary: tTG IgA does not help with allergies; it is a specific marker for celiac disease. If an allergy is suspected, appropriate allergy testing (e.g., specific IgE) is necessary.