Longitudinal monitoring of pediatric cystic fibrosis lung disease using nitrite in exhaled breath condensate.

Cystic fibrosis (CF) lung disease is characterized by airway inflammation and airway infection. Nitrites in exhaled breath condensate (EBC-NO(2)(-)) have been shown to be increased in children and adults with CF compared to healthy controls suggesting its use as a measure of airway inflammation. This longitudinal study aimed to evaluate if repeated measurements of EBC-NO(2)(-) are helpful in monitoring CF lung disease activity in children. Thirty-two children with mild CF lung disease (age 10.6 +/- 3.3 years) were recruited in two study centers. Follow-up visits occurred every 3 months over a period of 1 year with a total of five visits. Each visit included a clinical assessment incorporating a modified Shwachman-Kulczycki (SK) score, spirometry, an oropharyngeal swab, or sputum sample for bacterial analysis and an EBC sample analyzed for NO(2)(-) using a spectrophotometric assay. Furthermore at the first and the last visit a chest radiograph was done and scored (Chrispin-Norman (CN) score). There was no correlation of EBC-NO(2)(-) and parameters of spirometry, SK-score, or CN-score. Furthermore, increased EBC-NO(2)(-) levels did not predict subsequent pulmonary exacerbations. We conclude that repeated measurements of EBC-NO(2)(-) are not helpful in the longitudinal monitoring of mild CF lung disease in children.