Rationale and Comments

Transglutaminase (tTG) immunoglobulin A (IgA) antibody (anti-tTG IgA) is the recommended first-line screening test for celiac disease because it provides the best diagnostic sensitivity and specificity. Serum IgA should also be included to detect IgA deficiency. Anti-tTG IgG or deamidated gliadin peptide antibodies (IgG or IgA) could be appropriate as reflex tests in specific situations based on initial findings, although they have less specificity than the tTG IgA antibody. In particular, deamidated gliadin peptides result in a higher false-positive rate that can lead to further unnecessary testing and/or endoscopy.

Sponsoring Organizations

• American Society for Microbiology
• American Society for Clinical Laboratory Science
• American Society for Clinical Pathology

Sources

• ACG guidelines
• AGA guidelines

Disciplines

• Gastroenterologic

References

• Rubio-Tapia A, Hill ID, Kelly CP, et al. ACG clinical guidelines: diagnosis and management of celiac disease. Am J Gastroenterol. 2013;108(5):656-76; quiz 677.
• Husby S, Koletzko S, Korponay-Szabó I, et al. European Society Paediatric Gastroenterology, Hepatology and Nutrition Guidelines for diagnosing coeliac disease 2020. J Pediatr Gastroenterol Nutr. 2020;70(1):141-156.
• Husby S, Murray JA, Katzka DA. AGA clinical practice update on diagnosis and monitoring of celiac disease-changing utility of serology and histologic measures: expert review. Gastroenterology. 2019;156(4):885-889.