HealthMap

Anti-Tissue Transglutaminase (tTG) Antibody Test and Celiac Disease

Overview

• The anti-tissue transglutaminase (tTG) antibody test is currently considered the primary and most reliable blood screening test for celiac disease.
• It measures specific antibodies produced by the immune system when a person with celiac disease reacts to gluten.

Key Diagnostic Points

• High Accuracy: The IgA-tTG test has high sensitivity and specificity for detecting celiac disease in individuals consuming a gluten-containing diet.
• Dietary Requirement: The test is only accurate if the patient is currently eating foods that contain gluten (such as wheat, barley, and rye). Eliminating gluten prior to the test can cause false-negative results.
• Total IgA Check: Because an IgA deficiency can lead to false-negative tTG-IgA results, a total serum IgA level is often tested simultaneously.
• Confirmatory Testing: While a positive tTG test strongly suggests celiac disease, a definitive diagnosis typically requires confirmation via an intestinal biopsy performed by a gastroenterologist.

Clinical Considerations

• False positives can occasionally occur, particularly in the presence of other autoimmune disorders or liver conditions.
• Nutritional deficiencies resulting from malabsorption—such as low iron, ferritin, calcium, vitamin D, and B-complex vitamins—are frequently evaluated alongside celiac markers to assess overall nutritional status.