Noninvasive tests for eosinophilic esophagitis: Ready for use?

OBJECTIVE: To summarize the existing literature for several promising minimally invasive tests to measure disease activity in eosinophilic esophagitis (EoE). DATA SOURCES: Literature searches were performed using PubMed. Keyword combinations included eosinophilic esophagitis and minimally invasive techniques, including the esophageal string test, Cytosponge, transnasal endoscopy, technetium-labeled heparin, and noninvasive biomarkers. STUDY SELECTIONS: Retrospective and prospective observational studies, peer-reviewed reviews, and systematic reviews were selected. Data were reviewed and summarized. RESULTS: Various techniques have been developed in recent years to measure disease activity in EoE without the need for conventional endoscopy. Our review summarizes the data on these techniques, the benefits and limitations, and future directions for implementation in both research and clinical care. CONCLUSION: Tremendous progress has been made toward developing minimally invasive techniques to measure disease activity in EoE. Each of the techniques mentioned in this review has advantages and disadvantages, and some are closer to widespread use than others.