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Last reviewed: June 2020. The content for Optimal Testing: AACC's Guide to Lab Test Utilization has been developed and approved by the AACC Academy and AACC's Science and Practice Core Committee.

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This content is intended for healthcare professionals. If you are a patient, please visit the Celiac Disease Antibody Tests article.

As the fields of laboratory medicine and diagnostic testing continue to grow at an incredible rate, the knowledge and expertise of clinical laboratory professionals is essential to ensure that patients received the highest quality and most useful laboratory tests. AACC's Academy and Science and Practice Core Committee have developed a test utilization resource focusing on commonly misused tests in hospitals and clinics. Improper test utilization can result in poor patient outcomes and waste in the healthcare system. This important resource geared toward medical professionals recommends better tests and diagnostic practices. Always consult your laboratory director to make sure these recommendations are appropriate for your patient population.

Anti-Gliadin Antibody Optimal Testing Recommendations
  • Antibodies against native gliadin are not recommended for the detection of celiac disease (CD). The AGA test has a low diagnostic accuracy and is considered outdated.
  • Immunoglobulin A (IgA) anti-tissue transglutaminase (tTG) antibody is the preferred single test for the serologic diagnosis of CD in individuals over the age of 2 years. The IgA anti-TTG test has 95% or higher sensitivity and specificity for CD.
  • Recently, tests for antibodies against the deamidated peptide of gliadin (DGP) have replaced the classic AGA test. Anti-DGP assays carry a considerably higher diagnostic accuracy than the old AGA assays, especially in the IgG class, and can substitute for anti-tTG tests in patients with selective IgA deficiency.
  • When a high probability of CD exists, the possibility of IgA deficiency should be considered and total IgA measured.
  • An alternative approach is to include both IgA- and IgG-based testing in high probability patients. The combination of IgA anti-tTG and IgG anti-DGP assays show greater sensitivity than a single test, with very high specificity.
  • In patients with low IgA levels or selective IgA deficiency, IgG-based testing (IgG anti-DGPs and IgG anti-tTG) should be performed.
  • All diagnostic serologic testing should be done in patients on a gluten-containing diet.
  • Screening of asymptomatic adults, adolescents, and children is not recommended.
Accordion Title
Guidelines for Test Utilization
References

Rubio-Tapia A, et al. ACG Clinical Guidelines: Diagnosis and Management of Celiac Disease. Am J Gastroenterol. 2013; 108:656-76.

Snyder MR, and Murray JA. Celiac disease: advances in diagnosis. Expert Rev Clin Immunol. 2016;12(4):449-63.

Screening for Celiac Disease: USPSTF recommendation statement. Am Family Phys. 2017; 96:392.