Nasal nitric oxide levels and nasal polyposis in children and adolescents with cystic fibrosis.

Importance: The counterintuitive decrease of exhaled nitric oxide (NO) levels in a severe inflammatory disorder like cystic fibrosis (CF) is only scarcely understood. Because NO is important in a variety of regulatory processes in the lung, including host defense, inflammation, and bronchomotor control, it is necessary to search for clarifying mechanisms.

Objectives: To explore whether fractional exhaled NO (FENO) and nasal NO (nNO) levels are associated with CF genotype, nutritional status, presence of nasal polyps, pulmonary function, and airway colonization with Staphylococcus aureus and Pseudomonas aeruginosa in children with CF, and to investigate the effect of functional endoscopic sinus surgery (FESS) on FENO and nNO levels in children with CF and persistent sinonasal disease.