Nasal nitric oxide for early diagnosis of primary ciliary dyskinesia: Practical issues in children

SummaryBackgroundPrimary ciliary dyskinesia (PCD) is a genetic disease characterized by abnormally beating cilia. In these patients, levels of nasal nitric oxide (nNO) are lower than those observed in healthy subjects.ObjectivesWe identify the nNO levels in healthy pre-school uncooperative children and in PCD patients, in order the application of nNO measurement in the early identification of young children with PCD.MethodsWe measured nNO in 77 healthy children (50 uncooperative and 27 cooperative) and in 10 PCD patients. Fifteen cooperative healthy children were also asked to perform an uncooperative test.ResultsPCD patients presented low nNO levels (29.7±5.7ppb) compared to those observed in healthy children (358.8±35.2ppb; p<0.05). nNO levels were increased in healthy cooperative children (650±60.6ppb; p<0.05) as compared to those uncooperative aging more than 6 month (309.1±45.9ppb; p<0.05) or less (128.1±16.2ppb; p<0.05). Twenty-four uncooperative children with nNO values ⩽200ppb performed a second evaluation at least 6 months later and mean levels increased from 104.7±10.5ppb to 169.9±19.6ppb (p<0.05). In the 15 collaborative children nNO levels were higher during the breath holding manoeuvre (687.7±96.9ppb) than during the tidal breathing manoeuvre (335.9±57.9ppb; p