Secondary Ciliary Dyskinesia Research Articles

Evidence for secondary ciliary dyskinesia in patients with cystic fibrosis

BackgroundMucociliary clearance (MCC) impairment can be due to mucus abnormalities or to a ciliary dysfunction, which can be innate, or secondary to infection and/or inflammation. In cystic fibrosis (CF), it is well documented that MCC is impaired due to mucus abnormalities, but little is known concerning ciliary beating. This study aimed to confirm that ciliary dyskinesia is present in CF, and if this might be innate or secondary to the chronic infection and/or inflammation. MethodsCiliated epithelial samples were obtained by nasal brushing from 51 CF patients, and from 30 healthy subjects. Ciliary beating was evaluated using digital high-speed videomicroscopy at 37 °C, allowing to evaluate ciliary beat frequency (CBF) and the percentage of abnormal beat pattern (CBP); this was repeated after air-liquid interface (ALI) cell culture. ResultsCiliary dyskinesia was higher in CF patients than in healthy subjects, with a lower CBF and a higher percentage of abnormal CBP. Ciliary dyskinesia, already present in childhood, normalized after ALI cell culture. A chronic airway colonization did not worsen ciliary dyskinesia. ConclusionsWe showed that, in CF, a ciliary dyskinesia, present from childhood, might contribute to the impaired MCC. Our results also found that the abnormal ciliary beating was not associated with a chronic infection, and resolved after ALI cell culture, suggesting that ciliary dyskinesia in CF is not innate, and might be secondary to chronic inflammation.

SARS-CoV-2 Infection Dysregulates Cilia and Basal Cell Homeostasis in the Respiratory Epithelium of Hamsters.

Similar to many other respiratory viruses, SARS-CoV-2 targets the ciliated cells of the respiratory epithelium and compromises mucociliary clearance, thereby facilitating spread to the lungs and paving the way for secondary infections. A detailed understanding of mechanism involved in ciliary loss and subsequent regeneration is crucial to assess the possible long-term consequences of COVID-19. The aim of this study was to characterize the sequence of histological and ultrastructural changes observed in the ciliated epithelium during and after SARS-CoV-2 infection in the golden Syrian hamster model. We show that acute infection induces a severe, transient loss of cilia, which is, at least in part, caused by cilia internalization. Internalized cilia colocalize with membrane invaginations, facilitating virus entry into the cell. Infection also results in a progressive decline in cells expressing the regulator of ciliogenesis FOXJ1, which persists beyond virus clearance and the termination of inflammatory changes. Ciliary loss triggers the mobilization of p73+ and CK14+ basal cells, which ceases after regeneration of the cilia. Although ciliation is restored after two weeks despite the lack of FOXJ1, an increased frequency of cilia with ultrastructural alterations indicative of secondary ciliary dyskinesia is observed. In summary, the work provides new insights into SARS-CoV-2 pathogenesis and expands our understanding of virally induced damage to defense mechanisms in the conducting airways.

Analysis of the diagnosis of Japanese patients with primary ciliary dyskinesia using a conditional reprogramming culture.

Primary ciliary dyskinesia (PCD) is diagnosed through multiple methods, including transmission electron microscopy (TEM), a high-speed video microscopy analysis (HSVA), immunofluorescence (IF), and genetic testing. A primary cell culture has been recommended to avoid the misdiagnosis of secondary ciliary dyskinesia derived from infection or inflammation and improve diagnostic accuracy. However, primary cells fail to differentiate into ciliated cells through repeated passages. The conditional reprogramming culture (CRC) method, a combination of a Rho-kinase inhibitor and fibroblast feeder cells, has been applied to cystic fibrosis. The goal of this study was to evaluate the value of CRC in diagnosing PCD in Japanese patients. Eleven patients clinically suspected of having PCD were included. Airway epithelial cells were obtained from an endobronchial forceps biopsy and cultured at the air-liquid interface (ALI) combined with CRC. Ciliary movement, ultrastructure, and mutated ciliary protein evaluation were performed using HSVA, TEM, and IF, respectively. Genetic testing was performed on some patients. CRC yielded dense and well-differentiated ciliated cells with a high success rate (∼90%). In patients with PCD, the ciliary ultrastructure phenotype (outer dynein arm defects or normal ultrastructure) and IF findings (absence of the mutated ciliary protein) were confirmed after CRC. In DNAH11-mutant cases with normal ultrastructure by TEM, the HSVA revealed stiff and hyperfrequent ciliary beating with low bending capacity in CRC-expanded cells, thereby supporting the diagnosis. CRC could be a potential tool for improving diagnostic accuracy and contributing to future clinical and basic research in PCD.

Transmission electron microscopy study of suspected primary ciliary dyskinesia patients

Primary ciliary dyskinesia (PCD) is a rare autosomal recessive condition often presenting with chronic respiratory infections in early life. Transmission electron microscopy (TEM) is used to detect ciliary ultrastructural defects. In this study, we aimed to assess ciliary ultrastructural defects using quantitative methods on TEM to identify its diagnostic role in confirming PCD. Nasal samples of 67 patients, including 37 females and 30 males (20.3 ± 10.7 years old), with suspected PCD symptoms were examined by TEM. The most common presentations were bronchiectasis: 26 (38.8%), chronic sinusitis: 23 (34.3%), and recurrent lower respiratory infections: 21 (31.3%). Secondary ciliary dyskinesia, including compound cilia (41.4%) and extra-tubules (44.3%), were the most prevalent TEM finding. Twelve patients (17.9%) had hallmark diagnostic criteria for PCD (class 1) consisting of 11 (16.4%) outer and inner dynein arm (ODA and IDA) defects and only one concurrent IDA defect and microtubular disorganization. Also, 11 patients (16.4%) had probable criteria for PCD (class 2), 26 (38.8%) had other defects, and 18 (26.9%) had normal ciliary ultrastructure. Among our suspected PCD patients, the most common ultrastructural ciliary defects were extra-tubules and compound cilia. However, the most prevalent hallmark diagnostic defect confirming PCD was simultaneous defects of IDA and ODA.

Quantitative Assessment of Ciliary Ultrastructure with the Use of Automatic Analysis: PCD Quant.

The ciliary ultrastructure can be damaged in various situations. Such changes include primary defects found in primary ciliary dyskinesia (PCD) and secondary defects developing in secondary ciliary dyskinesia (SCD). PCD is a genetic disease resulting from impaired ciliary motility causing chronic disease of the respiratory tract. SCD is an acquired condition that can be caused, for example, by respiratory infection or exposure to tobacco smoke. The diagnosis of these diseases is a complex process with many diagnostic methods, including the evaluation of ciliary ultrastructure using transmission electron microscopy (the golden standard of examination). Our goal was to create a program capable of automatic quantitative analysis of the ciliary ultrastructure, determining the ratio of primary and secondary defects, as well as analysis of the mutual orientation of cilia in the ciliary border. PCD Quant, a program developed for the automatic quantitative analysis of cilia, cannot yet be used as a stand-alone method for evaluation and provides limited assistance in classifying primary and secondary defect classes and evaluating central pair angle deviations. Nevertheless, we see great potential for the future in automatic analysis of the ciliary ultrastructure.

A Revised Protocol for Culture of Airway Epithelial Cells as a Diagnostic Tool for Primary Ciliary Dyskinesia.

Air–liquid interface (ALI) culture of nasal epithelial cells is a valuable tool in the diagnosis and research of primary ciliary dyskinesia (PCD). Ex vivo samples often display secondary dyskinesia from cell damage during sampling, infection or inflammation confounding PCD diagnostic results. ALI culture enables regeneration of healthy cilia facilitating differentiation of primary from secondary ciliary dyskinesia. We describe a revised ALI culture method adopted from April 2018 across three collaborating PCD diagnostic sites, including current University Hospital Southampton COVID-19 risk mitigation measures, and present results. Two hundred and forty nasal epithelial cell samples were seeded for ALI culture and 199 (82.9%) were ciliated. Fifty-four of 83 (63.9%) ex vivo samples which were originally equivocal or insufficient provided diagnostic information following in vitro culture. Surplus basal epithelial cells from 181 nasal brushing samples were frozen in liquid nitrogen; 39 samples were ALI-cultured after cryostorage and all ciliated. The ciliary beat patterns of ex vivo samples (by high-speed video microscopy) were recapitulated, scanning electron microscopy demonstrated excellent ciliation, and cilia could be immuno-fluorescently labelled (anti-alpha-tubulin and anti-RSPH4a) in representative cases that were ALI-cultured after cryostorage. In summary, our ALI culture protocol provides high ciliation rates across three centres, minimising patient recall for repeat brushing biopsies and improving diagnostic certainty. Cryostorage of surplus diagnostic samples was successful, facilitating PCD research.

Histologic and Ultrastructural Findings in Dogs With Chronic Respiratory Disease Suspected of Ciliary Dyskinesia.

Mucociliary clearance is a main defense mechanism of the respiratory tract, which can be inherently impaired in primary ciliary dyskinesia (PCD) or reversibly altered in secondary ciliary dyskinesia (SCD). Limited diagnostic test availability likely leads to misdiagnosis or underdiagnosis of PCD in animals. This study evaluated the light and transmission electron microscopy (TEM) changes in the respiratory mucosa of 15 dogs with chronic respiratory disease suspected of PCD. Necropsy was performed in 1 case and 2 dogs were used as negative controls. PCD was confirmed in 1 dog, which presented with chronic otitis, bronchopneumonia, hydrocephalus and ultrastructural abnormalities in 84% of the assessed cilia, including absence of dynein arms and microtubular changes. The 14 other cases showed only nonspecific alterations, such as ciliary disorientation, compound cilia, ciliary edema, and axoneme bubbles in a minority of the evaluated cilia and were classified as SCD. Ciliary ultrastructural analysis can confirm a diagnosis of PCD if specific abnormalities exist. TEM remains an important investigational tool in veterinary medicine, as no other specific test for PCD in dogs has been standardized yet.

Matrix metalloproteinases and airway remodeling and function in primary ciliary dyskinesia

BackgroundThe balance between matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) is important in the regulation of airway damage. ObjectiveTo evaluate whether they are important in the pathophysiology of primary and secondary ciliary dyskinesia (PCD, SCD). MethodsWe measured sputum bacteriology, lung CT changes, MMPs, TIMPs and lung function in 86 patients (51 PCD, 35 SCD) in a cross-sectional study; the 10 controls studied did not have HRCT or sputum cultures. MMPs, TIMPs and lung function were evaluated longitudinally for up to one year in 38 PCD patients. ResultsAt baseline, there were no differences in MMPs, TIMPs and MMPs/TIMPs, between PCD and SCD but lower levels were found in controls. There was an association between poorer lung function with increasing levels of MMPs in PCD, while in SCD only MMP-9/TIMP-1 values correlated with FRC z-scores. Levels of MMPs and TIMPs significantly correlated with severity HRCT changes. Longitudinally, there were significant correlations between slope of changes in spirometric parameters and slope of change in sputum MMPs in PCD patients. ConclusionsIn conclusion, we report for the first time that increased MMPs are associated with worse airway damage in PCD and SCD, and thus are potential therapeutic targets.

Effect of TH2 cytokines and interferon gamma on beat frequency of human respiratory cilia

In asthmatic airways secondary ciliary dyskinesia contributes to impaired mucociliary clearance. To investigate underlying mechanisms, we studied the effects of cytokines associated with asthma phenotype on the ciliary beat frequency (CBF) in a cell culture model of ciliated human respiratory epithelial cells. Nasal respiratory epithelial cells of 21 patients were used to prepare multicellular cells (spheroids) in the presence of the T helper (TH) 2 cytokines interleukin (IL)-4, IL-5, IL-9 and IL-13, and the TH1 cytokine interferon gamma (IFN-γ). CBF was determined by high-speed video microscopy. Addition of IL-4 and IL-13 and IL-4 + IL-13 decreased the mean CBF by 17, 21, and 22%, respectively, compared with untreated controls. Addition of IL-5 and IL-9 lead to an increase in mean CBF (20 and 10%, respectively). Lower concentrations of IFN-γ (0.1 and 1 ng/ml) decreased mean CBF and higher concentrations (10 ng/ml) increased CBF by 6%. Addition of IFN-γ to IL-13 reversed the effect of IL-13 on the CBF of spheroids. Cytokines directly influence the ciliary function of respiratory epithelium and contribute to the impaired mucociliary clearance in asthmatic disease. Our study encourages further research to investigate IFN-γ as a treatment option in diseases with impaired mucociliary clearance like asthma.

S67 Lung Clearance Index (lci) Is A Sensitive Predictor Of High Resolution Computed Tomography (hrct) Scores In Children With Non-cf Bronchiectasis

Introduction and objectives LCI is a sensitive predictor of early cystic fibrosis (CF) lung disease, and correlates with HRCT better than spirometry (Thorax. 2008;63:129–134). The same is true in adults with non-CF bronchiectasis (Am J Respir Crit Care Med. 2014;189:586–592.), but by contrast, in PCD there were no relationships between LCI, HRCT or spirometry (Am J Respir Crit Care Med. 2013;188:545–549). It is unclear whether these differences reflect primary versus secondary ciliary dyskinesia, or CFTR versus non-CFTR disease. We hypothesised that in children with non-CF bronchiectasis, relationships between spirometry, LCI and HRCT will be similar to those in CF children and non-CF bronchiectasis adults, rather than PCD patients. Methods 12 children with non-CF bronchiectasis performed LCI and spirometry and underwent thoracic HRCT. HRCT scans were scored quantitatively (Thorax. 2013;68:532–539). Results were compared with those from large CF (n = 125) and PCD (n = 38) cohorts. Results In non-CF bronchiectasis there was a correlation between first second forced expired volume (FEV 1 ) and LCI (p = 0.009, r=-0.6), similar to that seen in CF (p 1 . Conclusions LCI is a good marker of structural lung disease in children with non-CF bronchiectasis and is more sensitive to HRCT abnormalities than spirometry, similar to adults, and CF at all ages. This suggests the different relationships seen in PCD result from the effects of primary versus secondary ciliary dyskinesia rather than CFTR versus non-CFTR lung disease. LCI may be useful in monitoring children with non-CF bronchiectasis, but this needs to be confirmed longitudinally. The results illustrate the importance of not extrapolating between different airway diseases.

Mannose-binding lectin 2 gene polymorphism and lung damage in primary ciliary dyskinesia.

Mannose-binding lectin (MBL) plays an important role in innate immunity and has been reported to be associated with the age-related decline in lung function in cystic fibrosis. MBL polymorphisms are associated with lung function decline in Primary Ciliary Dyskinesia (PCD). We performed sputum microbiology, spirometry pre- and post-administration of salbutamol, ciliary motion analysis, ultrastructural assessment of cilia, ciliogenesis in culture, and chest high resolution computed tomography in children with a clinical history of respiratory tract infections and/or presence of bronchiectasis suggestive of PCD or secondary ciliary dyskinesia (SCD). All subjects were evaluated for single nucleotide polymorphisms in the gene encoding MBL-2. The diagnosis of PCD was established in 45 subjects, while in the remaining 53 the diagnosis was SCD. A significant bronchodilator response was observed only in PCD associated with the MBL2-3 genotype, which is known to be associated with low/undetectable MBL serum levels. Also, bronchiectasis severity was significantly greater in subjects with MBL2-3 in both PCD and SCD. No other association was found between MBL genotypes and clinical findings. MBL plays a relatively minor role as a disease modifier in PCD. A similar finding in SCD supports the likely significance of this result.

Culture of Primary Ciliary Dyskinesia Epithelial Cells at Air-Liquid Interface Can Alter Ciliary Phenotype but Remains a Robust and Informative Diagnostic Aid

BackgroundThe diagnosis of primary ciliary dyskinesia (PCD) requires the analysis of ciliary function and ultrastructure. Diagnosis can be complicated by secondary effects on cilia such as damage during sampling, local inflammation or recent infection. To differentiate primary from secondary abnormalities, re-analysis of cilia following culture and re-differentiation of epithelial cells at an air-liquid interface (ALI) aids the diagnosis of PCD. However changes in ciliary beat pattern of cilia following epithelial cell culture has previously been described, which has brought the robustness of this method into question. This is the first systematic study to evaluate ALI culture as an aid to diagnosis of PCD in the light of these concerns.MethodsWe retrospectively studied changes associated with ALI-culture in 158 subjects referred for diagnostic testing at two PCD centres. Ciliated nasal epithelium (PCD n = 54; non-PCD n = 111) was analysed by high-speed digital video microscopy and transmission electron microscopy before and after culture.ResultsCiliary function was abnormal before and after culture in all subjects with PCD; 21 PCD subjects had a combination of static and uncoordinated twitching cilia, which became completely static following culture, a further 9 demonstrated a decreased ciliary beat frequency after culture. In subjects without PCD, secondary ciliary dyskinesia was reduced.ConclusionsThe change to ciliary phenotype in PCD samples following cell culture does not affect the diagnosis, and in certain cases can assist the ability to identify PCD cilia.

Ciliary ultrastructure in patients with chronic rhinosinusitis and primary ciliary dyskinesia

The Cilia represent one of the main mechanisms contributing to the clearance of microorganisms and particles from the respiratory epithelium. Primary ciliary dyskinesia (PCD) is a genetically determined disorder characterized by irreversible systemic dysmotility of the cilia. Secondary ciliary dyskinesia (SCD) differs from primary defects on the reversible ultrastructural alterations that can occur after any insult to a previously normal mucosa. Hence, this study aimed to describe and compare the main ultrastructural ciliary features in PCD and SCD through transmission electron microscopy. The most frequent PCD abnormalities were missing or short dynein arms, missing central microtubules, and displacement of one of the nine peripheral doublets. The most common changes found in SCD were compound cilia and peripheral microtubule alterations associated with modifications of the respiratory epithelium. PCD presented a higher percentage of altered cilia (>30 %) when compared to SCD (5 %), demonstrating that SCD is more limited in area than PCD. Whereas in PCD the changes in the dynein arms and in the central microtubules are fundamental for diagnostic confirmation, the diagnosis of SCD usually involves compound cilia and disarrangements in peripheral microtubules.

Rapid diagnosis of primary ciliary dyskinesia: cell culture and soft computing analysis

Diagnosis of primary ciliary dyskinesia (PCD) sometimes requires repeated nasal brushing to exclude secondary ciliary alterations. Our aim was to evaluate whether the use of a new method of nasal epithelial cell culture can speed PCD diagnosis in doubtful cases and to identify which are the most informative parameters by means of a multilayer artificial neural network (ANN). A cross-sectional study was performed in patients with suspected PCD. All patients underwent nasal brushing for ciliary motion analysis, ultrastructural assessment and evaluation of ciliary function after ciliogenesis in culture by ANN. 151 subjects were studied. A diagnostic suspension cell culture was obtained in 117 nasal brushings. A diagnosis of PCD was made in 36 subjects (29 of whom were children). In nine out of the 36 patients the diagnosis was made only after a second brushing, because of equivocal results of both tests at first examination. In each of these subjects diagnosis of PCD was confirmed by cell culture results. Cell culture in suspension evaluated by means of ANN allows the separation of PCD from secondary ciliary dyskinesia patients after only 5 days of culture and allows diagnosis to be reached in doubtful cases, thus avoiding the necessity of a second sample.

Primary ciliary dyskinesia, an orphan disease

Primary ciliary dyskinesia (PCD) is a rare autosomal recessive disease, caused by specific primary structural and/or functional abnormalities of the motile cilia, in contrast with the transitory abnormalities seen in secondary ciliary dyskinesia. Disease-causing mutations in at least 16 genes have already been identified. The true incidence of PCD may be higher than currently reported, because the diagnosis is challenging and often missed. For the confirmation of PCD, both ciliary motility as well as ciliary ultrastructure must be evaluated. An early and adequate diagnosis and therapy can theoretically prevent bronchiectasis. Measurement of nasal nitric oxide has some value as a screening test but cannot be performed in young children. In the respiratory tract epithelium, impaired mucociliary clearance leads to chronic and/or recurrent upper and lower respiratory tract infections. In up to 75% of the patients, respiratory manifestations start in the newborn period, although the diagnosis is often missed at that time. During embryogenesis, nodal cilia, which are motile cilia, determine the correct lateralization of the organs. Dysfunction of these cilia leads to random lateralization and thus situs inversus in approximately 50% of the patients with PCD. The tail of a spermatozoon has a structure similar to that of a motile cilium. Consequently, male infertility due to immotile spermatozoa is often part of the characteristics of PCD. Given the heterogeneity and the rarity of the disorder, therapy is not evidence-based. Many treatment schedules are proposed in analogy with the treatment for cystic fibrosis. Respiratory infections, situs inversus and male infertility are typical manifestations of PCD, a rare autosomal recessive disorder.

Development and Validation of a Method of Cilia Motility Analysis for the Early Diagnosis of Primary Ciliary Dyskinesia

BackgroundPrimary ciliary dyskinesia (PCD) is a clinically uniform entity, but cilia motility and structure can vary between patients, making the diagnosis difficult. The aim of this study was to evaluate the sensitivity and specificity in diagnosing PCD of a system of high-resolution digital high-speed video analysis with proprietary software that we developed for analysis of ciliary motility (Desinsoft-Bio 200). The secondary aim was to correlate nasal ciliary activity with clinical and structural abnormalities in PCD. Material and methodsWe analysed nasal mucociliary transport, cilia ultrastructure, nasal ciliary beat frequency and beat pattern studied by high-resolution digital high-speed video in 25 cases of PCD (11 Kartagener syndrome), 27 secondary ciliary dyskinesia and 34 healthy volunteers. ResultsNasal mucociliary transport was defective in both primary and secondary ciliary dyskinesia. Ciliary immotility was observed only in 6 patients with Kartagener syndrome and correlated with the absence of dynein. We observed a correlation between partial dynein deficiencies and ciliary dyskinesia. Cilia activity and structure were normal in secondary ciliary dyskinesia. ConclusionNasal mucociliary transport showed high sensitivity for PCD diagnosis with a low specificity. High-resolution digital high-speed video has a high sensitivity and specificity for diagnosing PCD. This system of video analysis is more useful than ultrastructural study and mucociliary transport for PCD screening. Dynein absence is correlated with cilia immotility and is more common in patients with Kartagener syndrome.

Desarrollo y validación de un método de análisis de la movilidad ciliar para el diagnóstico precoz de la discinesia ciliar primaria

BackgroundPrimary ciliary dyskinesia (PCD) is a clinically uniform entity, but cilia motility and structure can vary between patients, making the diagnostic difficult. The aim of this study was to evaluate the sensitivity and specificity in diagnosing PCD of a system of high-resolution digital high-speed video analysis with proprietary software that we developed for analysis of ciliary motility (Desinsoft-Bio 200). The secondary aim was to correlate nasal ciliary activity with clinical and structural abnormalities in PCD. Material and methodsWe analysed nasal mucociliary transport, cilia ultrastructure, nasal ciliary beat frequency and beat pattern studied by high-resolution digital high-speed video in 25 cases of PCD (11 Kartagener syndrome), 27 secondary ciliary dyskinesia and 34 healthy volunteers. ResultsNasal mucociliary transport was defective in both primary and secondary ciliary dyskinesia. Ciliary immotility was observed only in 6 patients with Kartagener syndrome and correlated with the absence of dynein. We observed a correlation between partial dynein deficiencies and ciliary dyskinesia. Cilia activity and structure was normal in secondary ciliary dyskinesia. ConclusionNasal mucociliary transport showed high sensitivity for PCD diagnosis with a low specificity. High-resolution digital high-speed video has a high sensitivity and specificity for diagnosing PCD. This system of video analysis is more useful than ultrastructural study and mucociliary transport for PCD screening. Dynein absence is correlated with cilia immotility and is more common in patients with Kartagener syndrome.

Nasal nitric oxide and nitric oxide synthase expression in primary ciliary dyskinesia

No study has evaluated the correlation between different expression of nitric oxide synthase (NOS) isoforms in nasal epithelial cells and nasal NO (nNO) level in primary ciliary dyskinesia (PCD). Gene expression of endothelial (NOS3) and inducible NOS (NOS2) and their correlation with nNO level, ciliary function and morphology were studied in patients with PCD or secondary ciliary dyskinesia (SCD). NOS3 gene polymorphisms were studied in blood leukocytes. A total of 212 subjects were studied (48 with PCD, 161 with SCD and three normal subjects). nNO level correlated with mean ciliary beat frequency (p = 0.044; r = 0.174). The lower the nNO level the higher was the percentage of immotile cilia (p<0.001; r = -0.375). A significant positive correlation between NOS2 gene expression and nNO levels was demonstrated in all children (p = 0.001; r = 0.428), and this correlation was confirmed in patients with PCD (p = 0.019; r = 0.484). NOS2 gene expression was lower in PCD than in SCD (p = 0.04). The NOS3 isoform correlated with missing central microtubules (p = 0.048; r = 0.447). nNO levels were higher in PCD subjects with the NOS3 thymidine 894 mutation, and this was associated with a higher ciliary beat frequency (p = 0.045). These results demonstrate a relationship between nNO level, NOS mRNA expression and ciliary beat frequency.

Agenesis of paranasal sinuses and nasal nitric oxide in primary ciliary dyskinesia

Agenesis of paranasal sinuses has only been described in case reports of patients with primary ciliary dyskinesia (PCD). As agenesis of paranasal sinuses may contribute to low nasal nitric oxide levels, a common finding in PCD, we speculated that this condition might frequently occur in PCD patients. Patients referred for PCD evaluation were consecutively recruited for 30 months. In addition to standard diagnostic testing for PCD, a computed tomography (CT) scan of paranasal sinuses was performed in all subjects. 86 patients (46 children aged 8-17 yrs) were studied. PCD was diagnosed in 41 subjects and secondary ciliary dyskinesia (SCD) was diagnosed in the remaining 45 subjects. Frontal and/or sphenoidal sinuses were either aplastic or hypoplastic on CT scans in 30 (73%) out of 41 PCD patients, but in only 17 (38%) out of 45 with SCD (p = 0.002). There was a significant inverse correlation between the score for aplasia/hypoplasia of each paranasal sinus and nasal NO values in the PCD patients (p = 0.008, r = -0.432) but not in SCD (p = 0.07, r = -0.271). The findings of aplasia/hypoplasia of the frontal and or sphenoidal sinuses may be part of the spectrum of PCD and this finding should prompt exclusion of this condition.

Cilia Motility and Structure in Primary and Secondary Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is a clinically uniform entity, although cilia motility and structure can vary among patients, making diagnosis difficult. Chronic sinusitis, bronchiectasis, sinus hypoplasia, secretory otitis media, and low fertility are common in PCD patients. The aim of this work was to correlate nasal ciliary activity with clinical and structural abnormalities in PCD. A secondary aim was to evaluate the usefulness of high-resolution digital high-speed video (DHSV) in the diagnosis of PCD. We analyzed nasal mucociliary transport and cilia ultrastructure by electron microscopy and studied nasal ciliary beat frequency (CBF) and beat pattern using high-resolution DHSV imaging in 34 healthy volunteers, 25 individuals with PCD (including 11 with Kartagener's syndrome [KS]with situs inversus), and 27 with secondary ciliary dyskinesia (SCD). Nasal mucociliary transport was defective in the PCD and SCD patients. Ciliary immotility was observed in only six KS patients and was correlated with the absence of dynein. We observed a correlation between partial dynein deficiency and an uncoordinated, stiffly vibrating ciliary beat. Cilia activity and structure were normal in the SCD patients. Nasal mucociliary transport showed a sensitivity of 100% for the diagnosis of PCD but has low specificity. High-resolution DHSV imaging has high sensitivity and specificity for the diagnosis of PCD. Video analysis is probably more useful than the study of mucociliary transport and cilia ultrastructure in screening for PCD. The absence of dynein was correlated with ciliary immotility and was more common in KS patients.