Background: Primary ciliary dyskinesia (PCD) is a disorder in which dyskinetic cilia cause impaired mucociliary clearance resulting in chronic destructive infectious and inflammatory disease of the upper and lower airways. A 99mTc tracer mucociliary clearance test is an in vivo function test of ciliary movement in upper and lower airways that can be measured specifically in the nose compartment as nasal mucociliary clearance (NMC) as well as separately in the pulmonary compartment as whole-lung pulmonary radiaerosol mucociliary clearance.

Material and Methods: By administering a droplet of 99mTc-albumin colloid tracer to the nasal concha media, the nasal mucociliary transport could be visualized using a gamma camera. From repeated planar images during a 10-minute period the NMC velocity could be quantitated. 

Results: NMC velocity was investigated in 7 patients with biallelic RSPH9, DNAH11, DNAI1, HYDIN, DNAH5, or CCDC114 PCD aged 9-31 yrs and in 5 healthy adult controls (HC). Nasal NO ranged from 24-208 ppb in PCD patients, and 660-1520 in HC. Median (range) NMC velocity in HCs was 0.85 (0.68-1.04) cm/min vs 0 (0-0 cm/min) in patients with PCD, P<0.0001. Thus, NMC was completely absent in all patients and different PCD genotypes, and regardless of nasal NO values. Success rate was 100% in both groups.

Conclusion: We report a feasible set up for fast NMC measurements that is easily applicable for any clinical trial involving PCD medication aiming to restore nasal mucociliary clearance. A highly significant discrimination in NMC velocity between PCD and healthy controls was shown.