The Minimally Invasive 1-Hr Esophageal String Test (EST) Monitors Therapeutic Changes in Mucosal Inflammation in Eosinophilic Esophagitis

Endoscopy, standard-of-care for monitoring eosinophilic esophagitis (EoE), assesses mucosal inflammation. The Esophageal String Test (EST), a minimally invasive swallowed capsule and immunoassays, quantifies EoE inflammation. We determined whether the EST/EoEScore can monitor disease in patients undergoing treatment. Thirty-three samples from 14 patients with EoE (7 children, 7 adults) who underwent repeat endoscopies and ESTs were studied. Biopsies were analyzed for peak eosinophil counts; ESTs were analyzed for EoEScores. Eosinophil counts and EoEScores significantly correlated during treatment, distinguishing patients with active EoE from treatment-associated remissions for 93.9% of ESTs performed. The EST can be used to longitudinally monitor responses to treatment in EoE.