Primary ciliary dyskinesia (PCD) is a heterogeneous disease with impaired mucociliary transport leading to respiratory disorders, hearing impairment and male infertility. PCD can be diagnosed by clinical features together with functional and structural analysis of the cilia. To prevent bronchiectasis with a marked reduction in quality of life, early diagnosis is essential. The rarity of PCD and the costs of ultrastructural analysis of cilia require a rational diagnostic concept. We therefore reviewed the literature and compared clinical manifestations as well as functional and structural analyses of the cilia in 28 patients (23 children, 5 adults) investigated between 1990 and 1998. All were thoroughly examined for other possible diseases before biopsy, and ten patients (35.7%; eight children, two adults) were diagnosed as having PCD. From the literature review and our findings we conclude that ciliary investigation is indicated (a) in patients who remain suspected of having PCD despite thorough clinical examination and exclusion of other disorders such as cystic fibrosis, allergy, immunologic disorders and alpha1-antitrypsin deficiency; (b) in patients with situs inversus suffering from chronic and/or recurrent airway infections; and (c) in patients with neonatal respiratory distress syndrome of "unknown" cause (i.e. after exclusion of hyaline membrane disease, aspiration syndromes, neonatal pneumonia, and pneumothorax as well as cardiovascular and metabolic diseases).
Conclusion: The combination of extensive clinical examination with functional and ultrastructural analysis of the cilia results in a high degree of accuracy in diagnosing PCD.