Assessment Of Vitamin D Role In The Pathogenesis Of Asthma In Vitamin D Resistent Patients
Condition: Asthma; Vitamin D Resistant Rickets
MeSH terms: Rickets; Rickets, Hypophosphatemic; Familial Hypophosphatemic Rickets; Asthma
Study type: Interventional

Summary: 
      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: 
      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.
    

Intervention name(s): Methacholine Challenge Test
Intervention type(s): Other
Intervention description(s): Evaluation of airway hyperreactivity as assessed by doubling dose of methacholine with determination of PC20
Other intervention name(s): Airway Hyperresponsiveness test
Intervention MeSH terms: Methacholine Chloride
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Screening
Keywords: Rickets; Vitamin D; airway hyperreactivity; Exhaled breath condensate