Primary ciliary dyskinesia: Observe the beat pattern!

Abstract

Respiratory cilia beat in a coordinated manner with a specific frequency and pattern (as shown in panel A of the figure), clearing mucus and debris from the airways. In primary ciliary dyskinesia (PCD), mucociliary clearance is impaired. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency, accompanied by specific abnormalities of the ciliary axoneme. It is unknown whether determining ciliary beat pattern related to specific ultrastructural ciliary defects might help in the diagnosis of PCD. Using digital high-speed video, Chilvers et al (p 518) have defined the ciliary beat pattern and beat frequency associated with 5 of the most common ultrastructural abnormalities responsible for PCD. They found that they were able to classify patients with PCD into 3 distinct groups on the basis of ciliary beat pattern. The authors observed a greater number of patients with a ciliary transposition defect (panels C and D) than previously reported. These patients were found to have a normal ciliary beat frequency but an abnormal gyrating beat pattern (panel B). The implication of this finding is that patients with this defect might be missed by the measurement of ciliary beat frequency alone. The authors conclude that different ultrastructural defects responsible for PCD result in predictable beat patterns. Recognition of these, in addition to measurement of ciliary beat frequency, might help in the diagnostic evaluation of patients with suspected PCD.FigureCiliary beat patterns: normal (panel A); ciliary transposition (panel B); ultrastructure of ciliary transposition—absence of the central pair (panel C); and peripheral microtubule transposition (panel D).View Large Image Figure ViewerDownload (PPT)FigureCiliary beat patterns: normal (panel A); ciliary transposition (panel B); ultrastructure of ciliary transposition—absence of the central pair (panel C); and peripheral microtubule transposition (panel D).View Large Image Figure ViewerDownload (PPT)FigureCiliary beat patterns: normal (panel A); ciliary transposition (panel B); ultrastructure of ciliary transposition—absence of the central pair (panel C); and peripheral microtubule transposition (panel D).View Large Image Figure ViewerDownload (PPT)