MICROTUBULAR DISCONTINUITIES AS ACQUIRED CILIARY DEFECTS IN AIRWAY EPITHELIUM OF PATIENTS WITH CHRONIC RESPIRATORY-DISEASES

A critical relationship exists between ordered ciliary ultrastructure and optimal mucociliary clearance in the respiratory airways. Structur ally defective cilia derived from heritable syndromes or from epitheli al cell injury may promote or exacerbate chronic disease processes. A lesion of airway epithelial cilia characterized by microtubular discon tinuities and previously associated with primary ciliary dyskinesia (P CD) has been documented in other forms of chronic airways diseases, in cluding cystic fibrosis (CF). Nasal cilia obtained by curettage of the inferior nasal turbinate from 89 patients without CF but exhibiting s ymptoms favoring PCD were evaluated by transmission electron microscop y. Of the 89 patients in the study group, 19 (21.4%) were diagnosed wi th PCD. Among the PCD patients, 16 (84.2%) exhibited microtubular disc ontinuities. Nine patients from this group without ultrastructural evi dence of PCD also exhibited these defects, however. Furthermore, seven of eight nasal biopsy specimens from patients with CF in a separate d isease control group exhibited microtubular discontinuities. Microtubu lar discontinuities were quantitatively negligible among control group s of healthy human subjects and individuals experimentally and natural ly subjected to acute airway injury. These data provide evidence that ciliary microtubular discontinuities represent acquired ciliary defect s reflective of chronic airway disease injury and are not components o f a primary structural abnormality in PCD.