Eosinophil Peroxidase Staining Enhances the Diagnostic Utility of the Cytosponge in Eosinophilic Esophagitis.

INTRODUCTION

We aimed to assess the diagnostic utility of eosinophil peroxidase (EPX) staining on Cytosponge (CS) samples in eosinophilic esophagitis (EoE).

METHODS

Esophageal biopsy (BX) samples from adult subjects with EoE were assessed using peak eosinophils per high-power field (eos/hpf), EPX, and the EoE histologic scoring system. EPX staining and eos/hpf were compared (BX vs CS).

RESULTS

CS EPX positivity correlated with eos/hpf (CS [ r = 0.82, P < 0.0001]; BX [ r = 0.65, P < 0.0001]) and EoE histologic scoring system (grade [ r = 0.62, P < 0.00001]; stage [ r = 0.61, P < 0.0001]). CS EPX identified subjects with active EoE (area under the curve = 0.86, P < 0.0001).

DISCUSSION: The correlation of CS EPX with eosinophilic inflammation and histologic disease severity supports its diagnostic utility in EoE.