Tissue Transglutaminase Antibodies, IgA and IgG Profile, Serum

Casandra

Casandra Test Code MC85019Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID TSTGPCPT Code 86364

Tissue Transglutaminase Antibodies, IgA and IgG Profile, Serum

Clinical Use

Use

This test is crucial for evaluating patients suspected of having celiac disease. It is used to test patients who present with compatible clinical symptoms, atypical symptoms, and those at increased risk due to factors like family history or previous diagnosis with associated conditions. It screens for dermatitis herpetiformis and monitors response to a gluten-free diet in patients with dermatitis herpetiformis and celiac disease. The presence of tissue transglutaminase antibodies is consistent with a diagnosis of celiac disease and possibly dermatitis herpetiformis. For individuals with moderately to strongly positive results, a celiac disease diagnosis is possible, and a small intestinal biopsy may be indicated for confirmation.

Special Instructions

The test should be performed while the patient is on a gluten-containing diet for accurate serologic evaluation. The test includes Tissue Transglutaminase Antibodies IgA and IgG as part of a comprehensive profile. If not ordering electronically, complete and send the Gastroenterology and Hepatology Test Request form with the specimen. Always centrifuge and aliquot serum into a plastic vial for submission.

Limitations

The test is not solely definitive for celiac disease diagnosis; patients may still need a duodenal biopsy for a conclusive diagnosis. The accuracy may be affected in patients who are already on a gluten-free diet before testing. For patients who are IgA deficient, testing for tTG IgG is necessary alongside IgA tests. Negative serology does not rule out the disease, particularly in patients with atypical symptoms or IgA deficiency. Further investigations might be required for such cases, which could include endoscopy and biopsy.

Test Details

FDA Approved