Sponge and Eosinophil Peroxidase (EPO) Staining

EPO staining on esophageal sponge samples had a strong association with peak esophageal eosinophil counts on endoscopic biopsy specimens in a small study of 26 patients Using a cut-off of 1.1 absorbance units in a colorimetric assay at a wavelength of 492nm the EPO stain had sensitivity and specificity of 1105 and 83% respectively for a peak eosinophil count of 15 eos/hpf on histologic endoscopic obtained biopsy specimens. The technique of EPO staining is standardized and can be completed in 45 minutes time. Currently, we have found esophageal sponge cytology sensitive and specific for assessment of esophageal eosinophilia. It allows disease activity assessment without endoscopy is much preferred by patients over the standard endoscopic technique of disease assessment. The process of specimen preparation in fairly tedious and interpretation takes significant experience. If EPO staining on non-endoscopic esophageal sponge studies was accurate at assessing disease activity, this is a tool that could be easily performed and interpreted with a rapid turnaround time.

Inclusion criteria

• 18 to 70 years of age
• Diagnosed with Eosinophilic Esophagitis > than 15 Eos phf and failed to respond to the PPI therapy
• Going through the six food elimination diet or have just completed elimination the six foods: fish, nuts, eggs, soy, wheat, and milk

Exclusion criteria

• Clinical evidence of infectious process potentially contributing to dysphagia (e.g. candidiasis, CMV, herpes)
• Other cause of dysphagia identified at endoscopy (e.g. reflux esophagitis, stricture, web, ring, achalasia, esophageal neoplasm)
• Esophageal minimal diameter < 13 mm on structured barium esophagram