RESUMO
RATIONALE: Electron microscopy (EM) of ciliated epithelium is widely used to diagnose primary ciliary dyskinesia (PCD). Ciliary beat frequency (CBF) has been used to screen samples to determine whether EM is indicated. Beat pattern analysis has been advocated as an additional diagnostic test. Neither has been subject to formal review. OBJECTIVES: To determine the ability of CBF and beat pattern analysis to predict EM-diagnosed PCD. METHODS: CBF calculation and beat pattern analysis, using high-speed video microscopy, and EM were performed on nasal tissue from 371 patients consecutively referred to the Leicester Royal Infirmary for diagnostic assessment for PCD. With EM as the "gold standard," receiver operating characteristic (ROC) curves were constructed and sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were calculated for CBF less than 11 Hz, ciliary dyskinesia score equal to or exceeding 2, at least 90% of ciliated edges beating dyskinetically, and an immotility index equal to or exceeding 10%. MEASUREMENTS AND MAIN RESULTS: PCD was excluded in 270 patients and confirmed in 70 by EM. The sensitivity, specificity, PPV, and NPV for CBF less than 11 Hz were 87.1, 77.2, 50.0, and 95.8%, respectively. These values were higher for ciliary dyskinesia scores equal to or exceeding 2 (92.5, 97.6, 91.2, and 98.0%) and when at least 90% of ciliated edges were dyskinetic (97.1, 95.3, 84.6, and 99.2%). ROCs confirmed that the ciliary dyskinesia score and percentage of dyskinetic edges were superior screening indices compared with CBF and the immotility index. CONCLUSIONS: The use of CBF alone to screen which biopsies should have EM will result in a significant number of missed diagnoses. Ciliary beat pattern analysis is a more sensitive and specific test for PCD with higher PPV and NPV.
Assuntos
Síndrome de Kartagener/diagnóstico , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Cílios/ultraestrutura , Epitélio/ultraestrutura , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Microscopia Eletrônica , Microscopia de Vídeo , Pessoa de Meia-Idade , Mucosa Nasal/ultraestrutura , Curva ROC , Adulto JovemRESUMO
The lungs and the nasal passages are continually exposed to respiratory pathogens, toxins, and particulate matter, and have evolved a very effective defense system to protect themselves. Mucociliary clearance is an essential part of this defence and relies on appropriate interactions between the ciliated epithelium, the height of the periciliary fluid, and mucus. Mucus acts as a physical barrier, trapping inhaled particles and pathogens, whilst cilia move both the mucus layer and fluid in the underlying periciliary layer. These defenses may be disrupted by viral and bacterial infections, by inhaled toxins, and by inherited diseases such as primary ciliary dyskinesia and cystic fibrosis.
Assuntos
Cílios/ultraestrutura , Transtornos da Motilidade Ciliar/fisiopatologia , Depuração Mucociliar/fisiologia , Doenças Respiratórias/fisiopatologia , Cílios/fisiologia , Humanos , Muco/fisiologiaRESUMO
Primary ciliary dyskinesia is an autosomal recessive disorder characterized by chronic upper and lower respiratory tract symptoms. We report the diagnosis of primary ciliary dyskinesia associated with a circular ciliary beat pattern in three siblings. This beat pattern is consistent with a ciliary transposition defect, where a peripheral microtubule doublet is transposed to the center of the ciliary axoneme to replace the absent central microtubule pair. However, in these siblings, ultrastructural analysis of the cilia revealed an absence of the central microtubule pair only. This variant of transposition with a circular ciliary beat pattern has not been described previously. In addition, this defect, together with the transposition defect, may help explain the mechanism of the circular beat pattern and also the absence of situs inversus in these patients.
Assuntos
Síndrome de Kartagener/genética , Microtúbulos/ultraestrutura , Árabes/genética , Biópsia , Bronquiectasia/genética , Criança , Consanguinidade , Tosse/genética , Diagnóstico Diferencial , Feminino , Genes Recessivos/genética , Humanos , Lactente , Síndrome de Kartagener/complicações , Síndrome de Kartagener/diagnóstico , Síndrome de Kartagener/fisiopatologia , Masculino , Microscopia Eletrônica , Depuração Mucociliar , Atelectasia Pulmonar/genética , Infecções Respiratórias/genética , Rinite/genética , Situs Inversus/genética , Tomografia Computadorizada por Raios X , Emirados Árabes UnidosRESUMO
Croup, or laryngotracheobronchitis, is a common childhood illness most often caused by viral infections. It is usually a benign, self-limiting disease, but can result in life-threatening upper airway obstruction. Until recently, it was not uncommon for children with severe croup to be admitted to intensive care for intubation. Management used to be limited to supportive measures, including mist therapy. The use of corticosteroids in patients with croup was controversial for many years but has, in the last decade, transformed the management of this disorder. Although corticosteroids do not alter the history of the viral infection, an adequate dose of oral or parenteral dexamethasone or nebulized budesonide has been shown to have a beneficial effect on the symptoms of croup.