Abstract
Background:Hand-held tidal breathing nasal nitric oxide (nNO) measurements reliably discriminate between patients with primary ciliary dyskinesia (PCD), cystic fibrosis (CF) and healthy subjects [Marthin et al. 2013 PLoS One].
Objective:To assess the accuracy of detecting PCD by hand-held nNO measurements in a tertiary referral population.
Methods:Patients of 4 years and older referred to the Dutch National PCD diagnostic center from November 2011 to October 2013, received two nNO measurements prior to a nasal curette biopsy. In addition, nNO measurements were performed in PCD patients during a regular visit to the outpatient clinic. PCD diagnosis was based on a combination of clinical symptoms, evaluation of ciliary movement by high-speed videomicroscopy and/or ciliary ultrastructure by electron microscopy.
Results:142 referred patients underwent PCD diagnostics (median age 10.0 years, IQR 6.7-15.3). nNO levels were measured successfully in 132 of 142 referred patients (93,0%) of which 129 (97,8%) could be measured in duplicate. In all known PCD patients (n=22) a duplicate nNO measurement could be performed. Median nNO level (ppb) in PCD referrals (24.0 IQR 11.0-33.8) and known PCD patients (26.8 IQR 18.3-84.1) was significantly lower compared to non-PCD referrals (221.8 IQR 81.9-426.0). Sensitivity and specificity for detecting PCD was 89.7% and 80.6%, respectively, using a cut-off of 71 ppb. The area under the ROC curve reached 0.88 (95% CI 0.79-0.97).
Conclusion:Hand-held tidal breathing nasal nitric oxide measurements show a high success rate and reasonable accuracy in detecting primary ciliary dyskinesia in a tertiary referral population.
- © 2014 ERS