Which serologic marker is used to monitor coeliac disease activity after a gluten-free diet?

Which serologic marker is used to monitor coeliac disease activity after a gluten-free diet?

• A. Anti-endomysial antibody
• B. Total IgA
• C. IgA anti-deamidated gliadin peptide
• D. IgA Tissue Transglutaminase antibody

Answer: (D)

Tracking disease activity after starting a gluten-free diet relies on the IgA antibody to tissue transglutaminase. This test tends to mirror the extent of intestinal mucosal damage: as the patient adheres to the diet, tTG IgA levels usually decline and can normalize, indicating mucosal healing. If the titers stay elevated or rise, it suggests ongoing gluten exposure or a poor response, prompting reevaluation of adherence or further investigation for complications. It's important to note that total IgA is checked to identify IgA deficiency, which would make IgA-based tests falsely negative and require alternative (IgG-based) markers. Anti-endomysial antibodies are highly specific but are less practical for routine monitoring due to variability and labor intensity, while IgA anti-deamidated gliadin peptide is less consistently correlated with mucosal healing. Hence, the serologic marker used to monitor activity is IgA tissue transglutaminase antibody.

Tracking disease activity after starting a gluten-free diet relies on the IgA antibody to tissue transglutaminase. This test tends to mirror the extent of intestinal mucosal damage: as the patient adheres to the diet, tTG IgA levels usually decline and can normalize, indicating mucosal healing. If the titers stay elevated or rise, it suggests ongoing gluten exposure or a poor response, prompting reevaluation of adherence or further investigation for complications.

It's important to note that total IgA is checked to identify IgA deficiency, which would make IgA-based tests falsely negative and require alternative (IgG-based) markers. Anti-endomysial antibodies are highly specific but are less practical for routine monitoring due to variability and labor intensity, while IgA anti-deamidated gliadin peptide is less consistently correlated with mucosal healing. Hence, the serologic marker used to monitor activity is IgA tissue transglutaminase antibody.