Mucociliary clearance (MCC) results from an effective interaction between the mucus layer and the normal coordinated ciliary beating. Ciliary dyskinesia, or an abnormal ciliary beating, is defined as an abnormal ciliary beat frequency (CBF) and/or ciliary beat pattern (CBP), and can be primary, or secondary to chronic infection or inflammation. In cystic fibrosis (CF), MCC is impaired due to dehydrated mucus, but recent data suggested a ciliary dyskinesia in CF patients, but it is unknown if this is primary, or secondary to chronic inflammation.

The aim of this study is to evaluate if ciliary dyskinesia is primary or secondary in CF patients.

Ciliated epithelial samples were obtained by nasal brushing from 10 CF patients and 5 healthy volunteers. Beating cilia were recorded using digital high-speed videomicroscopy at 37°C. Ciliary functional analysis (CFA) was assessed by CBF and by the percentage of dyskinetic CBP (%DK). CFA was repeated after Air-Liquid Interface (ALI) cell culture.

Our results confirm that ciliary dyskinesia is increased in CF patients compared with healthy volunteers, with no significant difference in CBF (13.3±2.9Hz vs. 12.5±1.1Hz, P=0.542), but a higher %DK (31.4±8.2% vs. 17.4±7.1%, P=0.007). However, after ALI cell culture, there is no difference between CF patients and healthy volunteers in CBF (15.6±2.1Hz vs. 15.0±2.3Hz, P=0.860), or in %DK (11.7±2.3% vs. 16.2±7.5%, P=0.371).

Our pilot study confirms that ciliary dyskinesia is present in CF patients, and may contribute to impaired MCC. However, after ALI cell culture, CFA is similar between CF patients and healthy volunteers, suggesting that ciliary dyskinesia may be secondary to chronic respiratory inflammation in CF patients.