Anti-gliadin antibodies identify celiac patients overlooked by tissue transglutaminase antibodies

For patients with suspected celiac disease, the American Gastroenterological Association recommends initial screening with anti-tissue transglutaminase antibody (tTG) and confirmation testing with small bowel biopsy. However, at Tripler Army Medical Center we routinely screen patients with both tTG and anti-gliadin antibodies (AGA) in combination. The purpose of this study was to evaluate whether this dual screening method adds to the evaluation of patients with suspected celiac disease or results in more false-positive results than tTG screening alone. A retrospective chart review of all tTG and AGA screening serologies at Tripler Army Medical Center between September 2008 and March 2012 was performed. For patients with positive serologic testing, small bowel biopsy results or reasoning for deferring biopsy were investigated. tTG was found to have a higher positive predictive value for celiac disease than AGA, however AGA identified 5 patients (19% of biopsy confirmed celiac disease) that had a negative tTG and would not have been identified by tTG screening alone. Using AGA in combination with tTG should be considered if the goal of screening is to identify all patients with celiac disease, with the understanding that this strategy will generate more false positive tests and result in additional patients undergoing small bowel biopsy.