Poster Session II - A199 EVALUATION OF PERIPHERAL ABSOLUTE EOSINOPHIL COUNT AS A BIOMARKER OF DISEASE ACTIVITY IN EOSINOPHILIC ESOPHAGITIS

Abstract Background At present, the gold standard for eosinophilic esophagitis (EoE) diagnosis and monitoring is upper gastrointestinal endoscopy (EGD) and biopsy of the esophageal mucosa. Unfortunately, the need for multiple and/or sequential treatments in this population can lead to patients needing recurrent, invasive EGDs for evaluation of disease activity and treatment response over time. Aims To evaluate the association between peripheral absolute eosinophil count (pAEC) and esophageal eosinophilia as a tool for monitoring EoE disease activity without the need for EGD. Methods A cross-sectional study is ongoing in adult EoE patients seen at a tertiary care centre in London, Canada. Participants who underwent an EGD with esophageal biopsy and had an available pAEC are included. Demographic data, pAEC, histological disease activity, and endoscopic findings were collected from each EGD encounter. Participants were evaluated for the association between 1) histological disease remission (