Exhaled Nitric Oxide as a Biomarker of Disease Activity in Eosinophilic Esophagitis

Study Overview
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Brief Summary
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There is currently no reliable, noninvasive biomarker for eosinophilic esophagitis (EoE), a chronic allergic diseases characterized by significant infiltration of eosinophils in the esophagus. Because eosinophils release nitric oxide, levels of exhaled nitric oxide (FeNO) are used routinely for guiding treatment in subsets of patients with asthma. FeNO levels are also elevated in immunological diseases that do not involve the airways. The investigators hypothesize that patients with EoE have elevated nitric oxide concentration in their exhaled breath and that changes in FeNO levels could be used to measure disease activity. The objective of this study is to determine the feasibility of using FeNO as a noninvasive surrogate marker for EoE disease activity. The investigators propose to measure serial exhaled nitric oxide (FeNO) levels on a group of patients with confirmed EoE, before, during and after the course of topical corticosteroid therapy to determine whether the level declines from pre-treatment level in individual patients.

Official Title
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Exhaled Nitric Oxide as a Biomarker of Disease Activity in Eosinophilic Esophagitis

Conditions
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Eosinophilic Esophagitis

Intervention / Treatment
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* Device: NIOX MINO® Airway Inflammation Monitor


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 7-65. Confirmed diagnosis of EoE. The diagnosis of eosinophilic esophagitis is based upon the presence of characteristic clinical features and large numbers of eosinophils in the esophagus on pathologic examination (≥15 eosinophils per high powered [400x] field in at least one specimen) despite acid suppression with a PPI for one to two months. The criteria also include normal gastric and duodenal mucosal biopsies and the exclusion of other causes. Clinical features in adults include dysphagia, pain and/or history of food impaction. Symptoms in children vary depending in part upon their age: feeding disorders (median age 2.0), vomiting (median age 8.1), abdominal pain (median age 12.0), dysphagia (median age 13.4), and food impaction (median age 16.8). Exclusion Criteria: Use of systemic or inhaled corticosteroids in the preceding 3 months. History of doctor-diagnosed asthma, acute or chronic rhinosinusitis. History of cirrhosis. History of kidney, heart or lung disease. Pregnancy

Ages Eligible for Study
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Minimum Age: 7 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Eosinophilic esophagitis (EoE)<br>Treatment-naïve EoE patients, age 7 -65 | Device: NIOX MINO® Airway Inflammation Monitor<br>* We will measure exhaled nitric oxide of patients with eosinophilic esophagitis pre-, during and post- treatment at pre-defined time intervals.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exhaled nitric oxide as a biomarker for disease activity in eosinophilic esophagitis | The objective of this study is to determine the feasibility of using exhaled nitric oxide (FeNO) as a noninvasive surrogate marker for EoE disease activity. We will measure FeNO levels on a group of patients with confirmed EoE before, during and after the course of topical corticosteroid therapy. | 2 years | 
| Exhaled nitric oxide as a biomarker for disease activity in eosinophilic esophagitis | Change in exhaled nitric oxide levels during corticosteroid treatment. | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exhaled nitric oxide as a biomarker for disease activity in eosinophilic esophagitis | Intra- and inter-patient variability in exhaled nitric oxide levels. | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Exhaled nitric oxide, Eosinophilic esophagitis