Limitations of nasal nitric oxide as a screening method of primary ciliary dyskinesia in childhood

Introduction: Nasal nitric oxide (nNO) has been proposed as a screening tool for primary ciliary dyskinesia (PCD). However, there are no reference values by age in consensus guidelines. Objectives: 1) To analyze differences in nNO among a group of patients with PCD and healthy controls. 2) To determine the proportion of pediatric PCD patients with nNO values similar to healthy population. Methods: Determination of nNO by electrochemical system (NIOX Vario®) in patients with DCP (diagnosis confirmed by digital high speed videomicroscopy) and healthy controls (without asthma, rhinitis or atopic dermatitis), aged between 7 and 60 years. Results: 32 patients (17 children, 53.1%) and 32 controls (18 children, 56.2%) were included. nNO differences were globally significant in both groups (161.4 ppb in PCD vs 2338.8 ppb in controls, p Conclusions: nNO may be normal in a high percentage of PCD children, so its role as a screening method in this group of age should be considered with caution. Definitive diagnostic tests should be performed in case of high clinical suspicion of the desease.