CHALLENGES TO IMPLEMENTATION
Diagnostic guidelines still favor EGD with biopsy for adults
The 2013 American College of Gastroenterology guidelines support the use of EGD and duodenal biopsy to diagnose CD in both low- and high-risk patients, regardless of serologic findings.7 In a 2019 Clinical Practice Update, the American Gastrointestinal Association (AGA) stated that when tTG-IgA titers are ≥ 10 times the ULN and EMAs are positive, the PPV is “virtually 100%” for CD. Yet they still state that in this scenario “EGD and duodenal biopsies may then be performed for purposes of differential diagnosis.”8 Furthermore, the AGA does not discuss informed and shared decision making with patients for the option of a “no-biopsy” diagnosis.8
Additionally, there may be challenges in finding commercial laboratories that report reference ranges with a clear ULN. Although costs for the serum tTG-IgA assay vary, they are less expensive than endoscopy with biopsy and histopathologic examination, and therefore may present less of a financial barrier.
