Evaluation of Histologic Cutpoints for Treatment Response in Eosinophilic Esophagitis

Aim: No consensus exists on the definition of successful treatment in eosinophilic esophagitis (EoE). The aim of this study was to identify the optimal histologic cutpoint to define successful treatment of EoE by assessing rates of symptomatic and endoscopic improvement.

Materials and methods: We performed a retrospective cohort study utilizing the University of North Carolina EoE Clinicopathologic Database between 2006 and 2013. Rates of symptomatic and endoscopic improvement were determined, as were post-treatment eosinophil counts. The area under the receiver operator characteristic curve (AUC) was calculated for symptomatic and endoscopic response at several possible eosinophil count cutpoints (eos/hpf). Predictors of response were also assessed.

Results: Of 224 treatments in 199 patients, 76% were associated with symptomatic improvement, 68% with endoscopic improvement, and 60% with both. Of treatments that resulted in a post-treatment count of <15 eos/hpf, 90% were associated with an endoscopic response, 88% with a symptomatic response, and 81% with both symptomatic and endoscopic responses. Using a <15 eos/hpf threshold, the area under the curves (AUCs) were 0.70, 0.78, and 0.75 for symptomatic, endoscopic, and symptomatic/endoscopic responses, respectively. Lower histologic cut-points did not result in a substantial gain in response, but decreased the AUC.

Conclusion: In this large cohort of EoE patients, rates of symptomatic and endoscopic improvement were generally associated with histologic improvement. A histologic cutoff for treatment response of <15 eos/hpf may balance clinical outcomes and test performance.