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


OBJECTIVE
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.


METHODS
Cross-sectional study (association with NO) and prospective study (effect of FESS on NO) in a tertiary care referral center. Patients included 95 children with CF in clinically stable condition at routine annual multidisciplinary examination, 13 of whom were referred for a FESS procedure.


METHODS
Functional endoscopic sinus surgery in children with CF and persistent sinonasal disease.


METHODS
Body mass index (BMI), FENO and nNO levels, results of flexible nasal endoscopy, pulmonary function tests (forced expiratory volume in 1 second and forced vital capacity), and airway cultures.


RESULTS
Children with nasal polyposis have significantly lower nNO levels than those without polyposis (median, 53 vs 140 parts per billion; P = .001); these values are negatively associated with colonization with S aureus (β = -.22; P = .04). After FESS, nNO values increase significantly, although not to normal levels.


CONCLUSIONS
In children with CF, the presence of nasal polyps is associated with significantly lower nNO levels than in children without nasal polyps. After FESS for nasal polyposis, nNO levels increase significantly, but not to normal levels. Low nNO levels are associated with S aureus colonization in the oropharynx and lower airways.
Department of Paediatric Respiratory Medicine and Allergology, University Medical Center, Utrecht, the Netherlands.
Karin M
KM
de Winter-de Groot
Sanne
S
van Haren Noman
Lucienne
L
Speleman
Anna G M
AG
Schilder
Cornelis K
CK
van der Ent
D000293:Adolescent; D000704:Analysis of Variance; D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000150:complications / Q000175:diagnosis*; D004724:Endoscopy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009296:Nasal Cavity / Q000737:chemistry* / Q000378:metabolism; D009298:Nasal Polyps / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D009569:Nitric Oxide / Q000032:analysis*; D011446:Prospective Studies; D012016:Reference Values; D012017:Referral and Consultation; D012129:Respiratory Function Tests; D018570:Risk Assessment; D062606:Tertiary Care Centers; D016896:Treatment Outcome
D009569:Nitric Oxide