Digital high speed videomicroscopy(DHSV) allows analysis of ciliary beat frequency(CBF) and pattern(CBP) of respiratory cilia in 3 planes. Normal reference data use a sideways edge to evaluate ciliary dyskinesia, and calculate CBF using the time for a cilium to complete 10 beat cycles. Variability in CBF within respiratory epithelium has been described, but data concerning variation of CBP is limited in healthy epithelium. This study aims to document variability of CBP within normal samples, to compare ciliary function in 3 profiles, and CBF calculated over 5 or 10 beat cycles.
Nasal brushing samples from 13 healthy subjects were recorded using DHSV in 3 profiles. CBP and CBF over 10 beat cycle were evaluated in all profiles and CBF re-evaluated over 5 beat cycles in the sideways edges.
82.1% of edges exhibited a uniform CBP. In the sideways profile, uniformity within the edge was lower(uniform normal CBP: 69.1%(sideways), 97.1%(towards), 92.0%(above)), and dyskinesia was higher. Inter-observer agreement for dyskinesia was poor. CBF was not different between profiles(p=0.8097), or between 10 and 5 beat cycles(p=0.1126).
Our study demonstrates a lack of uniformity and consistency in manual CBP analysis of healthy samples, emphasizing the risk of automated CBP analysis in limited regions of interest(ROIs), and of single and limited manual CBP analysis. The towards and above profiles may be used to calculate CBF, but may be less sensitive for evaluation of ciliary dyskinesia and CBP. CBF can be measured reliably by evaluation of only 5 ciliary beat cycles.