Introduction Mucociliary clearance impairment is well documented in asthma. Recent data demonstrated a ciliary dyskinesia in asthma. Chronic mucus hypersecretion(CMH) is linked with an increased severity in asthma, but it is unknown if CMH is linked with a higher ciliary dyskinesia.

Aims To compare ciliary function in severe asthma with or without CMH
 
Methods CMH was defined as cough and phlegm from chest on most days for ?3 consecutive months in a year, for ?2 consecutive years. Ciliated epithelial samples were obtained by nasal brushing from 20 severe adult asthmatics, 10 with, and 10 without, CMH. Ciliary function was assessed by ciliary beat frequency(CBF) and the percentage of abnormal beat pattern(%abnormal CBP). Normal values were obtained from 17 healthy adults. Patients had FENO measurement, and sputum evaluation.

Results Our results confirm that ciliary dyskinesia is increased in severe adult asthmatics compared with healthy subjects, with a lower CBF(11.9±2.1 Hz vs 14.2±2.3 Hz, p=0.002), and a higher %abnormal CBP(32.8[15.4-55.3]%, vs 17.9[11.3-23.7]%, p=0.005). However, there was no significant difference in CBF(11.8±2.1 Hz vs 11.9±2.2 Hz, p=0.892), nor in the %abnormal CBP(30.3[14.6-47.9]%, vs 36.2[20.7-59.1]%, p=0.530) between severe asthmatics with or without CMH. The prevalence of rhinosinusal comorbidities was similar in both groups, and Type-2 biomarkers were not significantly different.

Discussion Our results confirm a ciliary dyskinesia in severe asthma. Moreover, CMH was not associated with a worse ciliary dysfunction in severe asthma. In our small cohort, we did not confirm a link between CMH and Type-2 inflammation, and CMH was not explained by the presence of postnasal drips.