Bronchial and peripheral airway nitric oxide in primary ciliary dyskinesia and bronchiectasis

SummaryPrimary ciliary dyskinesia (PCD) is a genetic condition resulting in bronchiectasis. Exhaled gas nitric oxide (FENO) is reduced in PCD. A model of pulmonary NO exchange dynamics can be used to demonstrate relative contributions of bronchial (J′awNO) and peripheral airway (CalvNO) NO to the final FENO concentration. The aim of this study was to compare bronchial and peripheral airway contribution to FENO in patients with PCD, non-PCD bronchiectasis and healthy controls in order to establish the source of present FENO in these conditions and to compare these with severity of disease. NO was measured at 50, 100, and 200 ml/s using an NO analyser (NiOx Sweden). J′awNO and CalvNO were calculated according to a model of pulmonary exchange dynamics. PCD patients had reduced levels of J′awNO compared to healthy controls whereas patients with non-PCD bronchiectasis had elevated J′awNO levels. There was no difference in CalvNO between the three groups. In the disease groups CalvNO correlated negatively with FEV1. In conclusion patients with PCD had significantly reduced FENO at all expiratory flow rates. This was due to a significantly low bronchial NO. In contrast, peripheral airway NO was increased with more severe disease.