The impact of inhaled corticosteroids treatment on exhaled breath condensate in cystic fibrosis patients
Abstract
Pulmonary involvement in cystic fibrosis (CF) patients is accompanied by neutrophilic inflammation and impaired metabolism of nitric oxide (NO). Oxidative metabolites of NO are detectable in exhaled breath condensate (EBC).
The article deals with changes of EBC composition after treatment with inhaled corticosteroids (ICS), namely the pH and concentrations of nitrites (NO 2-) and nitrates (NO3-). Ten CF patients aged 23.4 +- 3.8 years were treated with ICS (budesonide 800 μg twice daily) for three months.
The pH of EBC was examined without deaeration immediately after collection. The concentrations of NO 2- a NO3- in EBC were assayed by liquid chromatography after derivatization with diaminonaphthalene.
Healthy controls (n = 12) were aged 27.2 +- 2.7 years. No significant change was detected in CF patients after ICS treatment in studied clinical parameters (BMI, FEV1, serum CRP and neutrophil cell count in the peripheral blood).
The EBC composition showed a significant increase of the pH (from 5.49 +- 0.68 to 6.17 +- 0.31; p = 0.005) and concentration of NO3 - (from 7.3 +- 1.8 to 20.9 +- 10.0 μmol/1; p = 0.003). No significant change was revealed in EBC concentration of NO2. - The composition of EBC in CF patients differed significantly from values in healthy controls in the following parameters: lower pH before ICS treatment (p = 0.01) and lower concentrations of NO3- before (p < 0.001) and after (p = 0.046) treatment with ICS.
We conclude that ICS treatment of stable CF patients led to significant changes of EBC pH and NO3- concentrations. Furthermore, CF patients have lower EBC pH and NO3- concentration than healthy controls.
Treatment with ICS resulted in the same pH values as in healthy controls but concentration of NO3- remained decreased.