Non- and semi-invasive methods of monitoring eosinophilic esophagitis

Monitoring inflammation associated with eosinophilic esophagitis (EoE) relies on the identification of biomarkers that provide an objective measure of disease activity. To date, this metric has been the number of eosinophils in the squamous epithelial tissue. The search for alternative biomarkers as well as alternative methods to capture them has been the topic of much research.

Based on clinical experience and a review of the literature, the aim of this chapter is to identify potential EoE biomarkers and methods to assess them.

With respect to the biomarkers, a number of candidates have arisen, including peripheral blood eosinophils, eosinophil granule proteins, Th2-related cytokines and exhaled nitric oxide. Methods to assess these biomarkers have included peripheral blood, luminal lavages and breath collections.

Future research will identify the best clinical outcome measure for EoE. While mucosal eosinophilia currently serves as a well-defined metric of inflammation, newer research studies will continue to address whether this number correlates reliably with other patient-reported outcomes, endoscopic findings, molecular analyses or other yet to be defined biomarkers.