Predictors of histologic response to dietary therapy in eosinophilic oesophagitis

Background: Dietary therapy successfully treats eosinophilic oesophagitis (EoE), but limited data exist on predictors of patient response. Aims: To determine response rates and to identify predictors of histologic response to elimination diets in adults with EoE. Methods: This was a retrospective, single-centre study of adults with PPI-refractory EoE undergoing dietary therapy with six food elimination diet (SFED) or extended six food elimination diet (ExSFED) in an outpatient setting from January 2012 to January 2019. Patient demographics, radiologic and endoscopic findings, endoscopic reference (EREF) scores, histology and symptoms were evaluated before and after food elimination. Histologic response was assessed via tissue obtained from endoscopically-guided biopsy or Cytosponge. Dietary therapy adherence was assessed via structured phone interview. Multivariable logistic regression analysis was performed to identify predictors of dietary response. Results: We included 68 patients, of whom 62% had a histologic response to dietary therapy (81% to SFED, 19% to ExSFED). Median duration of follow-up was 45 months (IQR, 34–53 months). On multivariable analysis, higher pre-SFED EREF score was the only variable associated with dietary non-response (OR 0.07, 95% CI 0.49, 0.98; p = 0.04). Conclusions: In adults with EoE, histologic dietary non-response to SFED was associated with a higher pre-SFED EREF score, suggesting that fixed structural disease may predict dietary non-response. Our additional observations of poor correlation between symptomatic and histologic flares, and identification of ExSFED responders, suggest that histologic confirmation should be sought before committing patients to lifelong dietary changes. We also recommend the consideration of restricting legumes and corn in SFED non-responders as ExSFED detected additional dietary responders.