Jornal de Pediatria - Vol. 76, Nº1, 2000 9
Jornal de Pediatria
Copyright © 2000 by Sociedade Brasileira de Pediatria
Primary ciliary dyskinesia in children
Maristella F. Toledo,1 Fabíola V. Adde2
Objectives: to point out primary ciliary dyskinesia as a cause of chronic respiratory disease in children. Methods: a 10 year literaturereview on Medline and by direct research about the subject. Results and Conclusions: primary ciliary dyskinesia is a disorder characterized by an abnormal mucociliary clearance. It affects both the upper and lower respiratory tracts and usually the clinical manifestations start in the first years of life. It can progress to bronchiectasis. Kartagener’s syndrome is the typical genetic manifestation.The diagnosis may be based on an abnormal saccharin test, but its confirmation depends on abnormal ultrastructure of the cilia or abnormal ciliary function. Many ciliary defects are currently known. The treatment is supportive, with measures to enhance mucociliary clearance, such as chest physiotherapy, prevention of infections by immunizations and prompt antibiotic therapy in the acute respiratoryinfections. J Pediatr (Rio J) 2000; 76(1): 9-16: primary ciliary dyskinesia, Kartagener’s syndrome, dinein.
Introduction Ciliary dyskinesia is the name attributed to diseases involving alterations in ciliary ultrastructure and/or function. As a consequence of these abnormalities, mucociliary transport is also affected. Mucociliary clearance constitutes one of the most important defensemechanisms of the respiratory tract, whereby bacteria, viruses, allergens, and pollutants are driven to the oropharynx, where they are swallowed. The interruption of this mechanism, as in ciliary dyskinesia, results in clinical disease. 1 The study of primary ciliary dyskinesia began about 90 years ago with the clinical observation of syndromes that
1. Assistant Physician, Pediatric Service,University Hospital, TaubatéUNITAU. 2. Assistant Physician, Pulmonary Unit, Children’s Institute, Hospital das Clínicas, FMUSP.
included pulmonary diseases, sinopathy, situs inversus, and male infertility. Situs inver-sus and bronchiectasis were first described by Siwert in 1904.1 Kartagener, in 1933, carefully studied 11 patients with sinusitis, bronchiectasis, and situs inversus, suggesting that theexistence of a common factor affecting all these patients. The triad became known as Kartagener’s syndrome.1 Kartagener’s syndrome had been previously called “immotile cilia syndrome,” until researchers concluded that most cilia presented uncoordinated or dyskinetic movements, not necessarily being immotile.1 It was only at that point that the name “primary ciliary dyskinesia” was proposed. 2Primary ciliary dyskinesia is an autosomal recessive inherited disease, with an approximate incidence of 1:15-30.000 individuals.3-5 It is classified as primary (congenital) or secondary (acquired).The most common defect is a deficiency in the number of dynein arms, resulting in weakening of the respiratory cilia and in spermatozoa motility. 9
10 Jornal de Pediatria - Vol. 76, Nº1, 2000
Primaryciliary dyskinesia in children - Toledo MF et alii
Dyskinesia occurs in all sites presenting ciliated epithelium, i.e., nasal fossae, paranasal sinus, middle ear, tracheobronchial tree, ependyma, efferent ducts, uterine tube, cervix endometrium, and prolongations of retina cells.4 In the present article, the literature concerning ciliary dyskinesia is reviewed taking into consideration theimportance of the subject and the little knowledge about this disorder in the differential diagnosis of recurrent or chronic infections of the respiratory tract.
The internal structure of the axoneme presents microtubules arranged in an array of nine couplets surrounding two central singlets, establishing a characteristic “9 + 2” cilia pattern. The microtubules are formed by protofilaments made...