Assessment Of Vitamin D Role In The Pathogenesis Of Asthma In Vitamin D Resistent Patients

Study Overview
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Brief Summary
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Research Title: Evaluation of airway reactivity, allergy and inflammatory mediators in exhaled breath condensate in vitamin D resistant rickets. Aim: To assess the effect of absence of vitamin D receptors on airway reactivity, allergy and inflammatory mediators in exhaled breath condensate in a prospective study evaluating patients with vitamin D resistant rickets and in healthy controls. Sample size: 40 participants in the two groups. Primary end point: Airway reactivity as assessed by methacholine challenge test. Secondary outcome parameters: All other parameters are the secondary end points.

Detailed Description
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Research Title: Evaluation of airway reactivity, allergy and inflammatory mediators in exhaled breath condensate in vitamin D resistant rickets. Introduction: Vitamin D seems to play a role in allergic and asthmatic reactions. Vitamin D resistant rickets patients lack vitamin D receptors and cannot absorb vitamin D. Aim: To assess the effect of absence of vitamin D receptors on airway reactivity, allergy and inflammatory mediators in exhaled breath condensate. Design: Prospective study evaluating these parameters in patients with vitamin D resistant rickets and in healthy controls. Participant selection: The study group will consist of vitamin D resistant rickets patients followed and treated at the Pediatric Endocrinology Department at our hospital. The study group will be compared to an age- and sex-matched healthy control group that had a negative methacholine challenge test. Sample size: 40 participants in the two groups. Intervention: Each subject will undergo evaluation including a respiratory questionnaire, pulmonary function tests, methacholine challenge test with determination of PC20, exhaled nitric oxide (eNO), and exhaled breath condensate (EBC). Venous blood will be analyzed for complete blood count + eosinophils, IGE levels, and Vitamin D levels. Prick skin test for inhaled allergens will be performed. All measurements will be evaluated in a single 3 hour visit, with no follow up study visits. Primary end point: Airway reactivity as assessed by methacholine challenge test. Secondary outcome parameters: All other parameters are the secondary end points.

Official Title
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Assessment Of Vitamin D Role In The Pathogenesis Of Asthma In Vitamin D Resistent Patients

Conditions
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Asthma, Vitamin D Resistant Rickets

Intervention / Treatment
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* Other: Methacholine Challenge Test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Vitamin D Resistent Rickets Age between 3 - 40 years Exclusion Criteria: Any Chronic Lung Disease Febrile Illness in last 2 weeks Inhaled Corticosteroids over the past 2 weeks Bronchodilators over the past 24 hours Participation in any other clinical studies over the past 4 weeks

Ages Eligible for Study
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Minimum Age: 3 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Screening
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Healthy Control<br> | Other: Methacholine Challenge Test<br>* Evaluation of airway hyperreactivity as assessed by doubling dose of methacholine with determination of PC20<br>* Other names: Airway Hyperresponsiveness test;|
| Active Comparator: Vitamin D resistant Rickets<br>Vitamin D resistant Rickets patients | Other: Methacholine Challenge Test<br>* Evaluation of airway hyperreactivity as assessed by doubling dose of methacholine with determination of PC20<br>* Other names: Airway Hyperresponsiveness test;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Metacholine Challenge Test | As assessed by methacholine challenge test with determination of PC20. | participants will be followed for the duration of hospital visit, an average of 3 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| IgE | in peripheral Blood count | participants will be followed for the duration of hospital visit, an average of 3 hours | 
| CBC | in peripheral Blood count | participants will be followed for the duration of hospital visit, an average of 3 hours | 
| Fractional Exhaled NO | determination of exhaled NO in Exhaled breath | participants will be followed for the duration of hospital visit, an average of 3 hours | 
| skin tests for inhaled allergens |  | participants will be followed for the duration of hospital visit, an average of 3 hours | 
| Inhaled breath condensate |  | participants will be followed for the duration of hospital visit, an average of 3 hours | 
| C reactive protein | in peripheral Blood count | participants will be followed for the duration of hospital visit, an average of 3 hours | 
| 25 OH vitamin D3 | in peripheral Blood count | participants will be followed for the duration of hospital visit, an average of 3 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Rickets, Vitamin D, airway hyperreactivity, Exhaled breath condensate