Does nasal rinsing reduce the need for repeat nasal brushing biopsies in a primary ciliary dyskinesia (PCD) diagnostic service? A pilot study.

Background: PCD is a rare genetic condition. Nasal brushing biopsies are used to sample ciliated epithelium for PCD diagnostic testing. High-speed video microscpy (HSVM) analysis of ciliary function can be difficult when excess mucus impedes cilia, increasing the likelihood or repeat testing (25%). Nasal rinsing (NR) can be used to clear mucus from nasal passages clinically. Aim: To determine whether NR (to reduce nasal mucus) reduces the need to repeat HSVM. Method: 20 prospectively recruited patients (aged 12-77 yrs, median 44, 50% male) were randomised to NR (9) or non-NR arms (11). NR with Neilmed Sinus Rinse was performed directly prior to nasal brushing biopsy. Blinded observers carried out HSVM and assigned a mucus score (0 no, 1 minor, 2 moderate, 3 major mucus impedance of sample). The repeat rate of these patients was audited post hoc. Results: There was a significant reduction in mucus impedance in the in the NR arm (p=0.031). Whilst 2 samples in the non-NR arm were insufficient for analysis due to excess mucus, all samples in the NR arm were sufficent. However, there was no difference in the number of samples repeated for HSVM (NR arm 33%, non NR arm 25%) Conclusion: This small pilot study suggests NR reduces mucus impedance in nasal brushing biopsies but this does not affect the need to repeat HSVM in equivocal cases. Secondary ciliary dyskinesia and PCD with subtle cilia abnormalities is likely to be the main reason for equivocal HSVM. Further research is needed.