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Sponge and Eosinophil Peroxidase (EPO) Staining

Study Purpose

Are we able to use the EPO staining technique using the sponge ?

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 18 Years - 70 Years
Gender All
More Inclusion & Exclusion Criteria

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

Trial Details

Trial ID:

This trial id was obtained from ClinicalTrials.gov, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Mayo Clinic
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Karthik Ravi, MD
Principal Investigator Affiliation Mayo Clinic
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Recruiting
Countries United States

The disease, disorder, syndrome, illness, or injury that is being studied.

Eosinophilic Esophagitis
Study Website: View Trial Website
Additional Details

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.

Arms & Interventions


Experimental: swallowed sponge device

Swallowing a sponge prior to a clinical upper endoscopy. Patients diagnosed with Eosinophilic Esophagitis (EoE) > than 15 Eosinophils per high power field (phf) and failed to respond to Proton Pump Inhibitors (PPI) therapy. Will be asked to swallow a sponge, this is a 10 minute procedure done in the office prior to their clinical upper endoscopy. This will be sent for histology, >15 Eos phf would be considered active disease. We will compare the results of the sponge using the EPO staining technique compared to histologic response.


Device: - swallowed sponge device

Swallowed sponge: Subjects having a clinical upper endoscopy will be asked to swallow the sponge 2 hours prior to EGD

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

Mayo Clinic in Rochester, Rochester, Minnesota




Mayo Clinic in Rochester

Rochester, Minnesota, 55905

Site Contact

Debra M. Geno, CRC



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