The Endoscopic Reference Score shows modest accuracy to predict either clinical or histological activity in adult patients with eosinophilic oesophagitis

Background Conflicting results have been recently reported for the accuracy of the Endoscopic Reference Score (EREFS), an standardised endoscopic classification, to predict the histological activity of eosinophilic oesophagitis (EoE). Aim To evaluate the accuracy of the EREFS to predict either histological or clinical activity of EoE. Methods Prospective multicentre study conducted in eight Spanish centres evaluating adult EoE patients, either naive or after treatment. Symptoms were evaluated before upper endoscopy through the Dysphagia Symptom Score, whereas researchers scored the EREFS immediately after the endoscopic procedure, unaware of the histological outcome. Results One hundred and forty-five EoE patients undergoing 240 consecutive endoscopic procedures were included. Exudates (P = 0.03), furrows (P = 0.03) and a composite score of inflammatory signs (exudates, furrows and oedema) (P < 0.001) accurately predicted histological activity. Exudates were the only endoscopic sign showing a good correlation with histological outcome after therapy. Furrows and oedema persisted in 50% and 70% of patients despite histological remission. No endoscopic feature exceeded 70% accuracy to predict histological activity. Likewise, no endoscopic finding could adequately predict dysphagia severity. Crepe paper mucosa, diffuse exudates and severe rings correlated with higher symptom scores. Conclusions Endoscopic findings assessed by the Endoscopic Reference Score did not correlate with histological or clinical disease activity in adult EoE patients. Only exudates correlated with peak eosinophil count and histological outcome, whereas furrows and oedema persisted in over half of patients despite histological remission.