Nasal ciliary ultrastructure and function in patients with primary ciliary dyskinesia compared with that in normal subjects and in subjects with various respiratory diseases

In an attempt to establish the relevance of ciliary ultrastructure to the pathophysiologic aspects of respiratory tract disease, we compared quantitatively the ultrastructure and function of cilia from healthy subjects (atopic and nonatopic nonsmokers, asymptomatic smokers) and patients with a variety of respiratory diseases (cystic fibrosis, chronic rhinitis, bronchiectasis associated with hypogammaglobulinemia, chronic bronchitis) with cilia from patients with primary ciliary dyskinesia (PCD). In healthy subjects and patients with non-PCD respiratory disease, approximately 5% of the cilia evaluated had ultrastructural abnormalities. Ciliary beat frequency was significantly higher in the chronic rhinitis group (15.3 +/- 1.2 Hz) than in the other non-PCD groups, which were within the normal range (12.5 +/- 1.7 Hz), and in all non-PCD cases ciliary wave form was normal. In each of these groups, normal mucociliary transport had been previously demonstrated. By contrast, in patients with PCD, the proportion of cilia with ultrastructural abnormalities was significantly greater than in the normal subjects and those with non-PCD respiratory disease (p less than 0.0001). In addition, beat frequency was significantly reduced, ciliary wave form was grossly abnormal, and pulmonary and nasal mucociliary transport were virtually absent. These findings demonstrate the relevance of ciliary ultrastructural abnormalities to altered ciliary function and lend support to the primary role of the demonstrated abnormalities in the respiratory tract disease of PCD.     

Primary mucociliary transport failure

Among the disorders associated with male infertility and chronic sinopulmonary infections, primary ciliary dyskinesia or cystic fibrosis is characterized by ciliary dysfunction or abnormality of mucus secretion. In addition, Young's syndrome differs from the former because of the absence of ultrastructural cilia disorders and from the latter because of normal sweat and pancreatic functions. However, a number of manifestations seen in these disorders appear to overlap each other, e.g., male infertility and chronic sinopulmonary infections which often develop bronchiectasis. Therefore, I would like to propose that the term 'muco(secretion)ciliary transport failure' is used for illnesses in patients with primary impairment of mucosecretion and/or ciliary transport in organs containing the mucociliary transport system. Primary mucociliary transport failure encompasses three hereditary disorders, that is, primary ciliary dyskinesia, cystic fibrosis and Young's syndrome. Ciliary activity is closely associated with mucus production. For a better understanding of the relationship between ciliary activity and mucus production, further basic and clinical studies should be attempted.     

Nasal nitric oxide measurements for the screening of primary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) presents to general practitioners with symptoms pertinent to a variety of specialists because of the involvement of ciliated epithelium in the upper/lower respiratory tract, ears, eyes and genital tract. There is no easy, reliable screening test for PCD, and thus, the majority of patients remain undiagnosed. Nitric oxide (NO) is measurable in nasal air of normal subjects and found to be low in cystic fibrosis (CF) and very low in PCD. Recently, it was suggested to play an important role in regulating ciliary motility. The aim of this study was to evaluate whether measurements of nasal NO could be used to screen for PCD. Nasal NO was measured from the nasal cavity by a chemiluminescence analyser in subjects with PCD, healthy controls, CF, idiopathic bronchiectasis, Young's syndrome and lone sinusitis. Nasal NO was significantly lower in PCD (64.0+/-36.6) compared with normal controls (759+/-145.8), idiopathic bronchiectasis (734+/-163.7), CF (447.5+/-162.6), lone sinusitis (1487+/-734) and Young's syndrome (644+/-129.9). Nasal NO was also significantly lower in PCD than CF patients. Measurement of nasal nitric oxide may therefore be used clinically in various specialities to screen suspected patients for primary ciliary dyskinesia.     

Immotile cilia syndrome (primary ciliary dyskinesia) and inflammatory lung disease

Abnormal mucociliary clearance can either be due to defects of mucus production and rheology or to abnormalities of the cilia. Ciliary dysfunction can be inherited as a genetically determined defect in axonemal structure (called the immotile cilia syndrome or primary ciliary dyskinesia) or acquired defects can result from airway injury. This article examines the defense of the lung as related to ciliary activity and addresses ways in which this activity can be modified by inflammatory mechanisms.     

Freeze-fracture analysis of the respiratory cilia from the bronchial mucosa of a patient with primary ciliary dyskinesia

Respiratory cilia of the bronchial mucosa from a 5-year-old boy with clinical evidence of classical Kartagener's syndrome (situs inversus, bronchiectasis and sinusitis) were first examined by means of transmission electron microscopy for identification of the axonemal defects described as typical for primary ciliary dyskinesia (PCD). Additional oscillography was performed on the cilia in vitro, which showed absence of a coordinated ciliary beat frequency. After clear classification of the case as PCD, a freeze-fracture examination of the respiratory cilia was performed, which revealed a higher density of intramembrane particles on the outer fracture face (E-face) than on the inner fracture face (P-face). The results were discussed with regard to probable pathogenetic aspects on PCD.     

Dyskinésie ciliaire primitive

Primary ciliary dyskinesia (PCD, MIM 242650) is an inherited respiratory disease caused by functional and ultrastructural abnormalities of respiratory cilia. This disorder, which affects 1 in 16,000 individuals, is usually transmitted as an autosomal recessive trait. In half the cases, PCD is associated with situs inversus (Kartagener syndrome). PCD is characterized by impaired mucociliary clearance resulting from a lack of ciliary motion, which is responsible for recurrent respiratory infections. The most frequent and first identified ciliary defect involves the dynein arms. The genetic heterogeneity underlying PCD is extremely important, and only three genes have as yet been identified in a few PCD patients with absence of outer dynein arms. The main clinical symptoms, at pulmonary and ENT levels, the abnormalities of ciliary structure and function, and the molecular basis of PCD will be reported in this review.     

Ultrastructural ciliary defects in children with recurrent infections of the lower respiratory tract

One hundred fifty-four children with recurrent or chronic infections of the lower respiratory tract compatible with the diagnosis of primary ciliary dyskinesia (PCD) were evaluated for the presence of ultrastructural ciliary abnormalities. Studies were performed on multiple samples of respiratory mucosa obtained by nasal and bronchial brushing. Twenty-eight children showed ultrastructural ciliary defects compatible with the diagnosis of PCD: Twenty-four presented dynein arm deficiency (either as isolated defect or in association with microtubular abnormalities), two had ciliary aplasia, and two showed microtubular abnormalities. Eleven patients with PCD had situs viscerum inversus, bronchiectasis, and chronic sinusitis (Kartagener's syndrome); one child with Kartagener's syndrome had normal ciliary structure. The appearance of respiratory symptoms within the first month of life, the colonization by Haemophilus influenzae, and a history of recurrent rhinitis and otitis were characteristically present in children with PCD. The clinical status of those patients who reached adolescence was, in our experience, remarkably good. An early diagnosis with adequate prevention and therapy of respiratory infections may have an important role in minimizing irreversible lung damage.     

Primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is an inherited disorder characterized by impaired ciliary function that leads to an array of clinical manifestations including chronic bronchitis, chronic sinusitis, chronic otitis media, situs inversus (in approximately 50% of cases), and infertility. The underlying genetic and molecular defects have not been defined. Molecular genetic studies have demonstrated multiple gene loci. In a few families, defects in genes encoding ciliary dynein proteins have been identified. PCD is an interesting disease to compare with cystic fibrosis (CF) because both are airway diseases associated with impaired mucociliary clearance and with chronic infection of the airways leading to bronchiectasis as well as chronic infection of the sinuses that may be associated with nasal polyposis. The progression of the lower airway disease appears less rapid in PCD. Unlike CF, PCD is commonly associated with chronic otitis media, respiratory problems during the neonatal period, and situs inversus, suggesting that ciliary function is also important for clearing fluid/bacteria from the middle ear, for clearing fluid from the fetal lung during the transition to an air-filled neonatal lung, and for directing laterality of organs during embryonic development. The management for PCD lung disease is similar to that for CF and other diseases with chronic bronchitis leading to bronchiectasis.     

Clinical and ultrastructural study on primary ciliary dyskinesia

We evaluated laboratory and radiological findings and examined tracheobronchial cilia by transmission electron microscopy in 9 patients with primary ciliary dyskinesia (PCD), in order to elucidate the clinical pictures of PCD and the relationship between PCD and diffuse panbronchiolitis (DPB) which was proposed as a new disease entity in Japan in 1969. The clinical pictures of our PCD patients were almost the same as that already described in several articles in Europe and North America; early onset of respiratory symptoms, high incidence of chronic sinusitis and otitis media exudative as well as infertility, continuous infections in the lower respiratory tracts (Hemophilus influenzae, Pseudomonas aeruginosa etc.). Tracheobronchial cilia obtained by brushing technique were immotile (6 out of 8 patients) or dyskinetic (2 out of 8 patients). Ultrastructural study of cilia revealed the lack of dynein arms in all patients: the lack of both outer and inner arms (4 patients), the lack of outer arms (2 patients), the lack of inner arms (2 patients). Chest X-ray films revealed situs inversus in six out of nine patients. According to the radiological findings (chest X-ray film, CT-scan, bronchogram), the patients were divided into three groups; I: localized bronchiectasis (5 patients), II: diffuse micronodular lesions without definite bronchiectasis (3 patients), III: diffuse micronodular lesions with bronchiectasis (1 patient). Two patients of the second group satisfied the clinical diagnostic criteria for DPB (Chest 83:63, 1983). In conclusion, PCD can cause a variety of respiratory tract lesions such as bronchiectasis, DPB and other types of peripheral airway disorders.     

原发性纤毛运动障碍1例及文献复习

目的 提高对原发性纤毛运动障碍(PCD)临床与病理特点的认识.方法 分析我院收治的1例PCD患者的临床资料及诊治经过,并复习相关文献.结果 患者临床表现为慢性咳嗽、咯痰、喘息;胸部CT表现为双肺弥漫的小结节改变并伴局部支气管扩张;经纤维支气管镜肺活检电镜病理表现为纤毛结构异常,动力臂缺失.其表现符合PCD.结论 PCD是由纤毛功能和(或)结构缺陷导致的一种常染色体隐性遗传病,容易误诊,其诊断依赖于纤毛超微结构检测.目前尚无标准治疗方案,以对症治疗为主.

Abstract：

Objective To improve the understanding of clinical and pathological characteristics of primary ciliary dyskinesia (PCD). Methods A case diagnosed with PCD was reported,and the related literatures were reviewed. Results The patient had cough,expectoration,and dyspnea. Chest CT scan showed diffuse nodules and local bronchieclasis. Transbronchial lung biopsy was done and transmission electron microscopy showed ciliary abnormalities and absence of dynein arms. Those findings were consistent with PCD. Conclusions PCD is an inherited disease characterised by functional and/or structural congenital abnormalities of cilia,and is often misdiagnosed. The diagnosis of PCD relies on the analysis of cilium ultrastructure. There is no specific therapy for PCD,and symptomatic treatment is recommended.     

原发性纤毛运动障碍1例及文献复习

目的 提高对原发性纤毛运动障碍(PCD)临床与病理特点的认识.方法 分析我院收治的1例PCD患者的临床资料及诊治经过,并复习相关文献.结果 患者临床表现为慢性咳嗽、咯痰、喘息;胸部CT表现为双肺弥漫的小结节改变并伴局部支气管扩张;经纤维支气管镜肺活检电镜病理表现为纤毛结构异常,动力臂缺失.其表现符合PCD.结论 PCD是由纤毛功能和(或)结构缺陷导致的一种常染色体隐性遗传病,容易误诊,其诊断依赖于纤毛超微结构检测.目前尚无标准治疗方案,以对症治疗为主.     

Acquired ciliary defects in bronchial epithelium of patients with chronic bronchitis

In order to quantify and classify ciliary changes of bronchial epithelium in chronic bronchitis, an ultrastructural study on biopsy specimens of 30 patients submitted to bronchoscopy was performed. Fourteen patients were affected by endoscopically and clinically confirmed chronic bronchitis, 8 showed an endoscopic picture of chronic bronchitis but without the clinical features of this pathology, 8 were free of chronic bronchitis. The mean percentage of abnormal cilia in control subjects (1.9 +/- 1.0%) was significantly lower than in patients either with only 'endoscopic' chronic bronchitis (5.7 +/- 2.6%; p less than 0.001) or with 'clinical' chronic bronchitis (14.8 +/- 15.9%; p less than 0.05). Like the ciliary body, the ciliary tip can also show some abnormalities. It is possible to subdivide them in two types: (1) ciliary membrane blebs; (2) ciliary membrane extrusions, variously shaped and sized, with homogeneous content. Bronchial cilia abnormalities become more serious as soon as the clinical picture worsens and this is likely to contribute to the impairment of the mucociliary clearance in chronic bronchitis patients.     

Steatosis associated with immotile cilia syndrome: an unrecognized relationship?

The present study deals with a case of hepatic parenchymal steatosis in a child with primary ciliary dyskinesia (immotile cilia syndrome) well documented by functional and ultrastructural evaluation of the ciliary epithelia. Hepatic steatosis was associated with ultrastructural evidence of retention of material either in the cisternae of the endoplasmic reticulum or in proximity of the Golgi apparatus of hepatocytes. It is suggested that the absence of dynein in the axoneme is probably part of a diffuse genetic defect which may extend to cytoplasmic, non axonemal, dynein and lead to a disturbance of various microtubule-dependent cell activities.     

Abnormalities of bronchial cilia in patients with chronic bronchitis

The fine structure of the bronchial cilia has been studied in biopsies of eighteen patients with chronic bronchitis and six nonsmoking controls. Abnormal cilia were noted in three of the control subjects and in all the patients with chronic bronchitis. The percentage of abnormal cilia ranged from 0 to 6% in control subjects and from 8 to 28% in patients with chronic bronchitis. Some ciliary abnormalities with changes in the axonemal 9 + 2 pattern of organisation were only detected in patients with chronic bronchitis. Compound cilia with two or more complete axonemes arranged parallel to one another and giant cilia with increased amounts of cytoplasmic matrix were observed in both control and diseased subjects. The possibility that these cilia represent aspects of biological variability or abnormalities of epigenetic origin is discussed. On the basis of the reported data, it is reasonable to suggest that the presence of atypical cilia of epigenetic origin contribute to the severe impairment of mucociliary transport associated with chronic bronchitis.     

Adult bronchiectasis revealing familial ciliary anomaly

We report a case of bronchiectasis in a 26-year-old man associated with the following congenital abnormalities: deafness, purulent bronchorrhea, nasal polyps, dysmorphic physical pattern and chronic sinusitis. Situs inversus was absent. A sampling was performed on the posterior nasal mucous membrane and displayed structural ciliary abnormality: a deficiency of the intern dynein-arm. The patient's bother was affected and had similar features: congenital bronchiectasis, deafness, mental deficiency and sinusitis. Young's syndrome was relevant in this case. Hereditary ciliary dyskinesia should be considered in adults with bronchiectasis together with rhinologic and alimentary canal disorders. Nasal biopsies are safe and allow cilia examination.     

A case of immotile cilia syndrome and a review of Japanese cases

A case of immotile cilia syndrome (ICS) is presented. A 34-year-old male, who had suffered from recurrent bronchitis, sinusitis and otitis media since early childhood, was admitted to Keio University Hospital complaining of productive cough and infertility. A saccharin test showed prolonged nasal clearance time, and semen analysis revealed immotile sperm. By electron microscopic observation of cilia of the nasal mucous epithelium and the sperm, inner and outer dynein arm defect, abnormal microtubular arrangement and compound cilia were detected and he was diagnosed as ICS. Thirty eight Japanese cases of ICS collected from the literature were analyzed concerning clinical manifestations, airway clearance, family history and ciliary ultrastructural abnormalities (Table 2, 3). Recurrent bronchitis, male infertility, chronic sinusitis, otitis and decrease in airway clearance were very common in these patients. Female infertility was more common than anticipated. The prevalence rate of situs inversus was more than 50%, probably due to more attention having been paid to Kartagener's syndrome in Japan. Recent studies show that the cilia of this syndrome is not always immotile but characterized by hypomotility or asynchrony, and have attempted to determine the relationship between each ciliary ultrastructural abnormality and motility pattern. It is necessary that more patients including incomplete and mild cases should be investigated.     

"Cyst-like" structures within the ciliary shafts in children with bronchiectasis.

"Cyst-like" structures within the ciliary shafts were considered in four adults as a primary defect involved in the development of bronchiectasis. In this study, the presence and the primary or secondary nature of this abnormality were assessed in children with bronchiectasis. High resolution computed tomography (HRCT) and nasal biopsies for motion analysis and transmission electron microscopy (TEM) evaluation of cilia were obtained in 45 children with recurrent lower airway infections and abnormal chest radiography. HRCT disclosed bronchiectasis in 35 out of 45 (77.8%) children and cyst-like structures were demonstrated with TEM in 29 out of 45 (64.4%) patients. Cyst-like structures were constantly associated with other ultrastructural abnormalities commonly observed in chronic inflammation, and were found both in subjects with primary and with secondary ciliary dyskinesia. When considering only patients with bronchiectasis, a significant correlation between prevalence of cyst-like structures and the severity of bronchiectasis was demonstrated. Follow-up (2-22 months) of seven patients demonstrated that in the five children with secondary dyskinesia, the ultrastructural defect completely disappeared and there was a small reduction in the abnormality in the two patients with primary dyskinesia. In contrast to one previous report, the reversibility of the defect suggests its secondary origin, which is most likely related to chronic airway inflammation.     

The emerging genetics of primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is an autosomal recessive, rare, genetically heterogeneous condition characterized by oto-sino-pulmonary disease together with situs abnormalities (Kartagener syndrome) owing to abnormal ciliary structure and function. Most patients are currently diagnosed with PCD based on the presence of defective ciliary ultrastructure. However, diagnosis often remains challenging due to variability in the clinical phenotype and ciliary ultrastructural changes. Some patients with PCD have normal ciliary ultrastructure, which further confounds the diagnosis. A genetic test for PCD exists but is of limited value because it investigates only a limited number of mutations in only two genes. The genetics of PCD is complicated owing to the complexity of axonemal structure that is highly conserved through evolution, which is comprised of multiple proteins. Identifying a PCD-causing gene is challenging due to locus and allelic heterogeneity. Despite genetic heterogeneity, multiple tools have been used, and there are 11 known PCD-causing genes. All of these genes combined explain approximately 50% of PCD cases; hence, more genes need to be identified. This review briefly describes the current knowledge regarding the genetics of PCD and focuses on the methodologies used to identify novel PCD-causing genes, including a candidate gene approach using model organisms, next-generation massively parallel sequencing techniques, and the use of genetically isolated populations. In conclusion, we demonstrate the multipronged approach that is necessary to circumvent challenges due to genetic heterogeneity to uncover genetic causes of PCD.     

原发性不动纤毛综合征四例并文献复习

目的 提高对原发性不动纤毛综合征的认识和诊断水平.方法 对2007年1月至2009年8月北京协和医院经电镜证实存在纤毛超微结构异常的4例原发性不动纤毛综合征(PCD)的临床资料进行分析,并进行相关的文献复习.结果 4例PCD中男性1例,女性3例;发病年龄0～10岁,确诊年龄15～53岁.临床表现:4例均有咳嗽、咳痰,鼻窦炎、喘息各3例,内脏反位2例,不育和不孕、中耳炎各1例;实验室检查:4例中低氧血症3例,阻塞性通气功能障碍伴有弥散功能减低2例,肺功能正常2例;胸部高分辨率CT示支气管扩张4例,双肺弥漫分布的微结节影3例,肺部斑片状影2例;电镜下可见动力臂缺失4例,纤毛稀少2例,微管排列异常或中央微管移位2例.结论 不合并内脏反位的PCD易被漏诊.对幼年发病,胸部影像学表现为弥漫支气管扩张或弥漫树枝出芽征样微结节的患者,需要鉴别PCD.可通过电镜观察纤毛超微结构以明确诊断.     

Mucus properties in children with primary ciliary dyskinesia: comparison with cystic fibrosis

OBJECTIVE: It has been assumed that cystic fibrosis (CF) lung disease is due in part to abnormal airway mucus. Primary ciliary dyskinesia (PCD) is a form of bronchiectasis that is similar to CF in many ways but is caused by congenital defects in mucociliary clearance. Our objective was to compare the biophysical and transport properties of CF and PCD sputa in subjects matched for age and degree of lung function impairment. DESIGN, SETTING, PARTICIPANTS: PCD patients (n = 19; mean age, 9.5 +/- 3.0 years [+/- SD]; FEV1, 65.0 +/- 7.8 L) were recruited from the clinic at the Royal Brompton Hospital. Patients with CF (n = 30, mean age, 10.8 +/- 2.6 years; FEV1, 61.8 +/- 22.8 L) were identified from the Wake Forest University School of Medicine CF Center. Pulmonary function testing and sputum collection were performed as part of routine, scheduled clinic visits. MEASUREMENTS: Pulmonary function was measured by spirometry, and sputum was collected during the pulmonary function test maneuver. Some patients were longitudinally assessed at visits during the course of 3 years. Sputum properties measured were dynamic viscoelasticity, wettability, cohesivity, interfacial (surface) tension, solids composition, DNA and interleukin (IL)-8 concentration, in vitro mucociliary transportability, and cough transportability. RESULTS: Inflammation as measured by IL-8 concentration was three times greater in the PCD sputa (p < 0.0001). There were no significant differences in the sputum biophysical or transport properties comparing CF with PCD sputum. CONCLUSIONS: It is unlikely that established CF lung disease is principally due to abnormal sputum properties, and it is more likely that the biophysical and transport properties reflect disease severity regardless of whether bronchiectasis is due to CF or PCD.