Redox Determinants of Severe Asthma (a Substudy of the Severe Asthma Research Program)
Redox Determinants of Severe Asthma (a Substudy of the Severe Asthma Research Program)
Hypotheses: 1) Airway pH regulation is abnormal in severe asthma; 2) In severe asthma, there
 is formation of cytotoxic nitrogen oxides and loss of beneficial nitrogen oxides in the
 airways
Specific Aim 1:Test hypothesis that airway pH regulation is abnormal in severe asthma.

 1a) Determine the effects of systemic corticosteroids on breath pH in children with severe
 and mild to moderate asthma.

 1b) Examine whether breath condensate pH and other biomarkers of oxidant stress can predict
 clinical outcomes in children with severe and mild to moderate asthma.

 1c) Identify whether increased Th1/Th2 cytokine ratio, and abnormalities in airway
 glutaminase, G-SNO-reductase, VATPase, and carbonic anhydrase are associated with airway pH
 disturbance in children with severe asthma.

 1d) Test whether rhinovirus infections, which reduce airway pH, persist longer or are more
 frequent in children with severe asthma than in children with mild to moderate asthma.

 1e) Examine the relationship between gastroesophageal reflux and proximal airway pH in
 children with severe asthma and mild to moderate asthma.
Inclusion Criteria:

 -  At least 6 years old

 -  Asthma diagnosis by physician

 -  Current treatment with an inhaled corticosteroid medication

 Exclusion criteria:

 -  Bronchiectasis

 -  Cystic Fibrosis

 -  Chronic Obstructive Pulmonary Disease