The Use of Fractionated Exhaled Nitric Oxide in the Diagnosis and Assessment of Disease Activity of Eosinophilic Esophagitis (Validation Phase)

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the relationship between fractionated exhaled nitric oxide, peripheral eosinophils, and plasma citrulline and ß-alanine in patients with eosinophilic esophagitis (EoE) compared to those without EoE. The hypothesis is that a combination of elevated fractional exhaled nitric oxide, increased peripheral eosinophils, and elevated plasma citrulline and ß-alanine is associated with active EoE.

Official Title
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The Use of Fractionated Exhaled Nitric Oxide in the Diagnosis and Assessment of Disease Activity of Eosinophilic Esophagitis

Conditions
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Eosinophilic Esophagitis

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pediatric patient, ages 5-18 years old, who will undergo esophagogastroduodenoscopy with biopsies at Children's Memorial Hermann Hospital, as part of the standard of care in the evaluation of EoE Signed informed consent by a parent or legal guardian Signed assent form by the child/adolescent subjects 7-18 years of age Exclusion Criteria: Past medical history of active asthma, active allergic rhinitis, inflammatory bowel disease (IBD), parasitic infection, hay fever and any exposure to smoking (including secondhand smoke) because these disorders are known to affect the FeNO levels Active respiratory tract infections at the time of FeNO evaluation because this can affect the result of the FeNO as well Asthma questionnaire and/or Spirometry test consistent with asthma

Ages Eligible for Study
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Minimum Age: 5 Years
Maximum Age: 18 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 |
| --- | --- |
| Active eosinophilic esophagitis<br> | |
| Eosinophilic esophagitis in remission<br> | |
| No eosinophilic esophagitis<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fractionated exhaled nitric oxide (FeNO) level | The FeNO measurement will be performed using a hand-held analyzer, the NIOX MINO (Aerocrine, Sweden). During this non-invasive procedure the patient is asked to perform a 4-6 second single-breath exhalation into the NIOX MINO, which measures FeNO in 100s with an electrochemical sensor. | baseline (day of first endoscopy) | 
| Fractionated exhaled nitric oxide (FeNO) level | The FeNO measurement will be performed using a hand-held analyzer, the NIOX MINO (Aerocrine, Sweden). During this non-invasive procedure the patient is asked to perform a 4-6 second single-breath exhalation into the NIOX MINO, which measures FeNO in 100s with an electrochemical sensor. | at about 4-12 weeks (day of second endoscopy) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Esophageal eosinophil counts as assessed by biopsy |  | baseline (day of first endoscopy) | 
| Esophageal eosinophil counts as assessed by biopsy |  | at about 4-12 weeks (day of second endoscopy) | 
| Blood eosinophil counts as assessed by complete blood count (CBC) |  | baseline (day of first endoscopy) | 
| Blood eosinophil counts as assessed by complete blood count (CBC) |  | at about 4-12 weeks (day of second endoscopy) | 
| Plasma beta-alanine level as assessed by high-performance liquid chromatography |  | baseline (day of first endoscopy) | 
| Plasma beta-alanine level as assessed by high-performance liquid chromatography |  | at about 4-12 weeks (day of second endoscopy) | 
| Plasma citrulline level as assessed by high-performance liquid chromatography |  | baseline (day of first endoscopy) | 
| Plasma citrulline level as assessed by high-performance liquid chromatography |  | at about 4-12 weeks (day of second endoscopy) |