Regional Analysis of Sinonasal Ciliary Beat Frequency

Abstract

Background Mucociliary clearance, a primary host defense mechanism, depends on mucus production and its clearance by the coordinated beating of cilia lining the airways. Numerous investigations have analyzed ciliary activity in brushings from the inferior turbinate. To date, only one study has investigated whether there exists variation in ciliary beat frequency (CBF) within the sinonasal cavity. We analyzed CBF from the inferior turbinate, uncinate process, and sphenoethmoid recess in nonsinusitis patients to determine regional variability of ciliary activity within the sinonasal cavity. Methods Explants of sinonasal epithelium were analyzed at 37°C. Beating cilia were visualized with differential interference contrast microscopy. Images were captured using a high-speed digital camera with a sampling rate of 250 frames per second. A one-dimensional tracking algorithm analyzed individual pixel grayscale values within each frame of the video. The differences in grayscale were plotted as a time-dependent waveform, and frequency was calculated as the inverse of the peak-to-peak distance. A minimum of three areas of beating cilia were analyzed per regional sample. Statistical analysis was performed with repeated-measures analysis of variance. Results Complete sampling of all three sites was accomplished in 10 patients. No difference in CBF within the sinonasal cavity was identified (p < 0.05). The mean CBF for all sites in all patients was 12.6 ± 2.9 Hz, in agreement with published values. Conclusion This study shows no regional differences in CBF within the sinonasal cavity, supporting previous work and validating analysis of inferior turbinate cilia.