The influence of the conservation of respiratory epithelial samples on ciliary functional analysis

Background: Primary ciliary dyskinesia(PCD) is an inherited otosinopulmonary ciliopathy in which respiratory cilia are stationary, or beat in a slow or dyskinetic manner. Digital high speed videomicroscopy(DHSV) allows ciliary functional analysis(CFA), including beat frequency(CBF) and beat pattern(CBP). DHSV is highly sensitive and specific for PCD diagnosis, but lacks standardization and evidence-based data. The technical process of ciliated epithelial samples before CFA varies among studies. Of importance, delay after sampling and temperature for samples conservation may impact CFA. However, these parameters have never been compared. Aims: To evaluate the stability of ciliary function over time when nasal brushing samples are conserved either in the fridge(4°C), or at room temperature(22°C). Methods: Ciliated epithelial samples were obtained by brushing the inferior nasal turbinate from 5 non-smoking healthy subjects. The samples were divided equally, and conserved either at 4°C or at 22°C. Beating cilia were recorded using DHSV at 37°C immediately(T0), then 9 hours after sampling(T9). CFA was assessed by CBF and the percentage of normal CBP. Results: There was no significant difference between CFA performed immediately or 9 hours after sampling, regardless of the sample storage temperature. Conclusion: This pilot study suggested that the stability of CFA may be preserved for 9 hours at 4°C and at 22°C. Larger studies are needed to confirm these preliminary results, notably in pathological conditions.