Altered sinonasal ciliary dynamics in chronic rhinosinusitis

Background: Although multiple etiologies contribute to the development of rhinosinusitis, a common pathophysiological sequelae is ineffective sinonasal mucociliary clearance, resulting in stasis of sinonasal secretions, with subsequent infection, and persistent inflammation. The respiratory cilia beat continually at a basal rate, while during times of stress, such as exercise or infection, ciliary beat frequency (CBF) increases, accelerating mucus clearance. Previous investigations have led to conflicting results with some authors reporting decreased CBF while others have found normal values of CBF in patients with chronic rhinosinusitis (CRS). Additionally, these studies have only analyzed basal CBF. The goal of this study was to compare the basal as well as the stimulated sinonasal CBF in patients with CRS versus controls. Methods: A dual temperature controlled perfusion chamber, differential interference contrast microscopy, and high-speed digital video were used to analyze both basal and adenosine triphosphate (100 mu M)-stimulated CBF in human sinonasal mucosal explants. Results: Although no difference in basal CBF was detected between control and CRS patients, a marked difference in stimulated CBF was noted. Exogenously applied adenosine triphosphate resulted in a 50-70% increase of CBF in control tissue with a minimally observed CBF increase in explants from CRS patients. Conclusion: Dynamic regulation of respiratory ciliary activity is critical for the respiratory epithelium to adapt to varying environmental situations. Thus, diminished or absent adaptation could predispose the sinonasal cavity to accumulation of inhaled infectious and noxious particulate matter resulting in infection/inflammation. Our findings suggest that CRS patients have decreased sinonasal ciliary adaptation to environmental stimuli.