Nasal nitric oxide and nitric oxide synthase expression in primary ciliary dyskinesia

No study has evaluated the correlation between different expression of nitric oxide synthase (NOS) isoforms in nasal epithelial cells and nasal NO (nNO) level in primary ciliary dyskinesia (PCD). Gene expression of endothelial (NOS 3) and inducible (NOS 2) NOS and their correlation with nNO, ciliary function and morphology were studied in patients with PCD or secondary ciliary dyskinesia (SCD). NOS 3 gene polymorphisms were studied in blood leukocytes. Two hundred and twelve subjects were studied, (48 with PCD, 161 with SCD, 3 normal subjects). nNO correlated with mean ciliary beat frequency (p=0.044, r=0.174). The lower the nNO the higher was the percentage of immotile cilia (p NOS 2 gene expression was lower in PCD than in subjects with SCD (p=0.04). NOS 3 isoform correlated with missing central microtubules (p=0.048, r=0.447). nNO levels were higher in PCD with the NOS 3 894T mutation and this was associated with higher ciliary beat frequency (p=0.045). These results demonstrate a relationship between nNO, NOS mRNA expression, and ciliary beat frequency.