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
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.
- At least 6 years old
- Asthma diagnosis by physician
- Current treatment with an inhaled corticosteroid medication