Primary ciliary dyskinesia

. A 14-YEAR-OLD girl with past history of asthma, allergic rhinitis, and conjunctivitis was admitted to the hospital for progressive dyspnea. The physical examination revealed inspiration and expiration wheezing associated with diffuse ronchi and rales. PFT revealed mild flow obstruction not reversible after inhaled salbutamol (200 mg); ABG on room air showed PaO2 of 66.2 mmHg, PaCO2 of 34.6 mmHg and pH 7.425. The prick test demonstrated strong positivity for house-dust mite and atmospheric pollens (Parietaria and Assenzio). Tests of sweat and the genetic map for cystic fibrosis were negative. Radiographic examination (chest, HRCT) was not specific. Light microscope. The microstructure of the mucosa under examination appeared to be within the limits of normality. Highgrade enlargement showed the free surface (no mucus) of the covering epithelia to be occupied by cilia regularly distributed. Transmission electron microscope. With low-grade enlargement, it was found that the cilia were homogeneously distributed and had about the same diameter. However, with strong enlargement, we noticed: 1) plasmalemma well structured but thickened in every microvillus 2) free space between plasmalemma and axonoma was variable: for some cilia, it was above average for slight edema 3) well-developed axonoma; it was possible to distinguish the central microtubules from the pairs of peripheral microtubules, which maintain a regular arrangement in space 4) absence of dynein lateral arms and reduction of connection rays and loss of nexina pontes in the subcellular organization of the axonoma. Primary ciliary dyskinesia (PCD) is a rare, heterogeneous disorder, usually transmitted with a recessive autosomal tract, and characterized by the axonomal anomalies of the respiratory epithelium cilia. In the diagnostic examination for PCD, electron microscopy represents an important tool, even if it remains difficult to distinguish the congenital ciliary alterations from those following chronic respiratory pathologic states. According to Rossmann et al. (1), the report of aspecific ciliary damage involving less than 5% of the epithelial cells would suggest an acquired disorder. However, the loss of differentiated epithelial cells and the ultrastructural defects of the ciliary system are much larger in carriers of PCD than in patients with damage deriving from a chronic respiratory pathologic state (2). We found ciliary ultrastructural damage, both specific (ciliary bodies with loss of axonoma arms) and aspecific. The diversity in specific ciliary ultrastructure among different patients with the same clinical symptoms is due to the fact that the immotile cilia syndrome is a heterogeneous disease, and the underlying defect may reside in any of a great number of ciliary genes. A commonly observed defect is the absence of the so-called dynein arms; other reported ultrastructural abnormalities include abnormal radial spokes and improperly oriented, absent, or additional microtubule assemblies. In 10–20% of cases, the living cilia are seen to be immotile but the ciliary ultrastructure appears to be quite normal; this probably reflects an underlying defect in membrane pumps or in other proteins not visible in electron micrographs. In our case, the subcellular organization of the axonoma showed the absence of dynein lateral arms, reduction of connection rays, and loss of nexina pontes. The aspecific aspects, as related to the phlogistic asthmatic situation, could be considered an aggravating factor in the early clinical manifestation of the genetic disorder. Therefore, in addition to an increased incidence of respiratory infections with chronic cough and expectoration of mucopurulent sputum, an asthmatic presentation may be encountered in PCD. Houtmeyers et al. (3) described the possible modifications of the mucousciliary clearance (MCC) caused by drugs used in patients with an insufficient mucous-ciliary transport system. However, the kind of drugs administered to our patient (corticosteroid and b2-agonist) during the period preceding the diagnosis did not influence the pathologic situation codified as PCD. In fact, it must be pointed out that the use of a b2-agonist is ALLERGY 2001: 56:1105 -1108 . COPYRIGHT G MUNKSGAARD 2001 . ISSN 0105-4538 . ALL RIGHTS RESERVED . CONTRIBUTIONS TO THIS SECTION WILL NOT UNDERGO PEER REVIEW, BUT WILL BE REVIEWED BY THE ASSOCIATE EDITORS .