Freeze-fracture analysis of the respiratory cilia from the bronchial mucosa of a patient with primary ciliary dyskinesia

Relevance of the Ciliary Ultrastructure in Primary and Secondary Ciliary Dyskinesia: A Review

Primary ciliary dyskinesia is a group of autosomal recessive inherited disorders characterized by the absence of any mucociliary transport. In the cilia of most patients specific ultrastructural abnormalities are present, such as the dynein deficiency, the spoke deficiency, and the absence of the central pair of microtubules. Secondary ciliary dyskinesia, the acquired (infectious, toxic, or inflammatory) form, is mostly correlated with other abnormalities, such as microtubular abnormalities and compound cilia. However, the great overlap, the missing links, and the confusing observations limit the insight in pathogenesis and pathophysiology and may require new in vitro systems.

Freeze fracture study of airway epithelium from patients with primary ciliary dyskinesia

BACKGROUND

The airway cilia of patients with primary ciliary dyskinesia (PCD) exhibit several anomalies when studied by transmission electron microscopy, but little is known about the ultrastructural organisation of ciliary membranes in these patients. Freeze fracture replication of airway epithelium from patients with PCD provides a means of achieving high resolution views of cell membrane structure. Ciliary necklaces are a specialised structural feature of ciliary membranes thought to serve as a timing mechanism for ciliary beat, and their characterisation in the cilia of patients with PCD may contribute new insights into the pathophysiology of this syndrome.

METHODS

The nasal epithelium of three patients with PCD was freeze fractured and replicated with platinum and carbon shadowing. The resultant preparations were examined by transmission electron microscopy and the ciliary necklaces were compared with similar preparations of nasal biopsy specimens from normal healthy subjects.

RESULTS

The ciliary necklaces of the three patients with PCD were normal with no overt differences from those of healthy individuals.

CONCLUSIONS

The defective ciliary motility observed in patients with PCD does not appear to result from membrane dysfunction associated with overt disorganisation of ciliary necklace structure.

Abnormal length of cilia--a cause of primary ciliary dyskinesia--a case report

A 7-year-old Turkish boy had suffered from chronic coughing from early childhood. Severe bronchiectasis in the right lung was confirmed by bronchography. Ciliary beat frequency determined in a bronchial mucosal biopsy was markedly decreased (5.7 Hz). Electron microscopy revealed cilia with a length of 15 microns. No structural abnormality was found. A possible link between the abnormally long, slow beating cilia and the clinical symptoms is discussed.