
Primary ciliary dyskinesia (PCD) is the most common form of a group of inherited disorders characterized by defects in the structure and function of all ciliated cells throughout the body. Common variants include immotile cilia syndrome (ICS) and Kartangener's syndrome. Progressive respiratory disease is the major health consequence of PCD, but other problems may include male infertility, hearing loss, visual deficits, congenital heart disease, renal dysfunction and, less commonly, central nervous system problems. Clinical manifestations vary greatly depending upon the nature of the abnormality.
Until recently, PCD was thought to affect approximately one person in 15,000. New diagnostic tools, including tracheal biopsy examination with transmission electron microscopy (TME) and modern genetic tests have resulted in sharp increases in positive diagnoses, leading some authorities to suspect that as many as one person in 1,500 may have an inherited ciliary disorder.
In PCD, airway ciliary dysfunction results in diminished secretion clearance in upper and lower airways. Although other important clearance mechanisms, including cough, may function normally, residual secretions trigger chronic sinusitis, otitis media, nasal polyposis and chronic, progressive respiratory illness.
PCD management closely resembles the model for CF care. Therapeutic goals are to control symptoms, maintain lung health and prevent or delay the onset of bronchiectasis. Standard therapy includes prompt treatment of acute exacerbations, antibiotics to suppress microbial load, reduction of excessive inflammatory response and, most importantly, secretion clearance interventions. Since patients with PCD are unable to clear pulmonary secretions naturally, they are totally dependent upon assistive daily airway clearance therapy (ACT). Therapy should begin at the time of diagnosis.
High-frequency chest compression (HFCC) therapy is recognized as a standard of care ACT for patients with lung disease caused by impaired secretion clearance. Currently, HFCC is used by more than 70% of American CF patients and by a growing number of those with PCD. HFCC is a logical ACT choice for PCD and CF because it accelerates the rate of secretion clearance from both peripheral and central airways. By reducing exposure to excess, bacteria-laden mucus, respiratory health is sustained and disease progression is moderated.