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Refereed/Peer-reviewed Nasal nitric oxide (nNO) is extremely low in most people with primary ciliary dyskinesia (PCD) and its measurement is an important contributor to making the diagnosis. Existing guidelines and technical standards focus on nNO measurements in older, cooperative children using chemiluminescence analysers. However, measurements of nNO in pre-school-age children (age 2–5 years) may facilitate early diagnosis and electrochemical rather than chemiluminescence analysers are widely used. Pre-schoolers often need different methods to be employed when measuring nNO. Hence, a European Respiratory Society Task Force has developed this technical standard as the first step towards standardising sampling, analysis and reporting of nNO measured as part of the diagnostic testing for PCD in all age groups, including pre-school-age children. Furthermore, we considered both chemiluminescence and electrochemical analysers that are in use worldwide. There was a paucity of quality evidence for electrochemical analysers and sampling methods used in young children, and the Task Force proposes future research priorities to allow updates of this technical standard.

Ciliopathies may be classed as primary or motile depending on the underlying ciliary defect and are usually considered distinct clinical entities. Primary ciliopathies are associated with multisystem syndromes typically affecting the brain, kidney, and eye, as well as other organ systems such as the liver, skeleton, auditory system, and metabolism. Motile ciliopathies are a heterogenous group of disorders with defects in specialised motile ciliated tissues found within the lung, brain, and reproductive system, and are associated with primary ciliary dyskinesia, bronchiectasis, infertility and rarely hydrocephalus. Primary and motile cilia share defined core ultra-structures with an overlapping proteome, and human disease phenotypes can reflect both primary and motile ciliopathies. CEP164 encodes a centrosomal distal appendage protein vital for primary ciliogenesis. Human CEP164 mutations are typically described in patients with nephronophthisis-related primary ciliopathies but have also been implicated in motile ciliary dysfunction. Here we describe a patient with an atypical motile ciliopathy phenotype and biallelic CEP164 variants. This work provides further evidence that CEP164 mutations can contribute to both primary and motile ciliopathy syndromes, supporting their functional and clinical overlap, and informs the investigation and management of CEP164 ciliopathy patients.

Introduction In primary ciliary dyskinesia (PCD) impaired mucociliary clearance leads to recurrent airway infections and progressive lung destruction, and concern over chronic airway infection and patient-to-patient transmission is considerable. So far, there has been no defined consensus on how to control infection across centres caring for patients with PCD. Within the BEAT-PCD network, COST Action and ERS CRC together with the ERN-Lung PCD core a first initiative has now been taken towards creating such a consensus statement. Methods A multidisciplinary international PCD expert panel was set up to create a consensus statement for infection prevention and control (IP&C) for PCD, covering diagnostic microbiology, infection prevention for specific pathogens considered indicated for treatment and segregation aspects. Using a modified Delphi process, consensus to a statement demanded at least 80% agreement within the PCD expert panel group. Patient organisation representatives were involved throughout the process. Results We present a consensus statement on 20 IP&C statements for PCD including suggested actions for microbiological identification, indications for treatment of Pseudomonas aeruginosa, Burkholderia cepacia and nontuberculous mycobacteria and suggested segregation aspects aimed to minimise patient-to-patient transmission of infections whether in-hospital, in PCD clinics or wards, or out of hospital at meetings between people with PCD. The statement also includes segregation aspects adapted to the current coronavirus disease 2019 (COVID-19) pandemic. Conclusion The first ever international consensus statement on IP&C intended specifically for PCD is presented and is targeted at clinicians managing paediatric and adult patients with PCD, microbiologists, patient organisations and not least the patients and their families., For the first time ever, an international consensus statement for infection prevention and control in PCD is presented. A total of 20 statements were developed in a collaboration of BEAT-PCD, COST Action, ERS CRC and ERN-LUNG PCD Core Network. https://bit.ly/3yuahKt

BackgroundPrimary ciliary dyskinesia (PCD) is a heterogeneous inherited disorder caused by mutations in approximately 50 cilia-related genes. PCD genotype–phenotype relationships have mostly arisen from small case series because existing statistical approaches to investigating relationships have been unsuitable for rare diseases.MethodsWe applied a topological data analysis (TDA) approach to investigate genotype–phenotype relationships in PCD. Data from separate training and validation cohorts included 396 genetically defined individuals carrying pathogenic variants in PCD genes. To develop the TDA models, 12 clinical and diagnostic variables were included. TDA-driven hypotheses were subsequently tested using traditional statistics.ResultsDisease severity at diagnosis, measured by forced expiratory volume in 1 s (FEV1) z-score, was significantly worse in individuals with CCDC39 mutations (compared to other gene mutations) and better in those with DNAH11 mutations; the latter also reported less neonatal respiratory distress. Patients without neonatal respiratory distress had better preserved FEV1 at diagnosis. Individuals with DNAH5 mutations were phenotypically diverse. Cilia ultrastructure and beat pattern defects correlated closely to specific causative gene groups, confirming these tests can be used to support a genetic diagnosis.ConclusionsThis large scale, multi-national study presents PCD as a syndrome with overlapping symptoms and variations in phenotype according to genotype. TDA modelling confirmed genotype–phenotype relationships reported by smaller studies (e.g. FEV1 worse with CCDC39 mutation) and identified new relationships, including FEV1 preservation with DNAH11 mutations and diversity of severity with DNAH5 mutations.

Primary ciliary dyskinesia is an incurable, rare, inherited, chronic condition. Treatment includes regular clearing of airway mucus, aggressive treatment of infections and management of hearing loss. Caregiver burden has not been explored, hence we interviewed 18 English speaking mothers and 6 English speaking fathers of children under 6 years who were diagnosed with PCD around the world. The parents described how the child’s diagnosis, treatment regimen, and health status impacted their life. They discussed the impact of the COVID-19 pandemic and they talked about the different ways they cope with challenges that arise. The need for integrated social care is discussed.

Air&ndash, 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.

ObjectiveIn England, the National Health Service commissioned a National Management Service for children with primary ciliary dyskinesia (PCD). The aims of this study were to describe the health of children seen in this Service and compare lung function to children with cystic fibrosis (CF).DesignMulti-centre service evaluation of the English National Management PCD Service.SettingFour nationally commissioned PCD centres in England.Patients333 children with PCD reviewed in the Service in 2015; lung function data were also compared with 2970 children with CF.ResultsMedian age at diagnosis for PCD was 2.6 years, significantly lower in children with situs inversus (1.0 vs 6.0 years, p1) was 76.8% in PCD (n=240) and 85.0% in CF, and FEV1 was lower in children with PCD up to the age of 15 years. Approximately half of children had some hearing impairment, with 26% requiring hearing aids. Children with a lower body mass index (BMI) had lower FEV1 (pHaemophilus influenzae.ConclusionsWe provide evidence that children with PCD in England have worse lung function than those with CF. Nutritional status should be considered in PCD management, as those with a lower BMI have significantly lower FEV1. Hearing impairment is common but seems to improve with age. Well-designed and powered randomised controlled trials on management of PCD are needed to inform best clinical practice.

Primary ciliary dyskinesia (PCD) is an autosomal recessive condition characterized by dysmotile cilia. Typically associated with defects in the cilia structure, it results in impaired mucociliary clearance of pathogens from the lungs and sinuses. Consequently, patients suffer from recurrent sinopulmonary and middle ear infections. We report on the management of a 5-year-old boy who presented with increased work of breathing, fever and crepitations, with an existing diagnosis of PCD with situs inversus totalis. Chest X-ray imaging revealed right lower lobe collapse. He was managed with intensive physiotherapy, nebulized mucolytic agents and antibiotics. However, due to a poor response, he underwent flexible bronchoscopy, which allowed removal of a mucus plug and subsequent re-expansion of his collapsed lobe. Although there is limited evidence for the management of PCD, here we discuss the accepted strategies for its management, based on expert opinion and guidelines for other suppurative lung diseases.

We welcome the correspondence from Lavie and Amirav (1), highlighting the difficulties diagnosing primary ciliary dyskinesia (PCD) and the role of high-speed video analysis (HSVA). As members of the European Respiratory Society (ERS) PCD Diagnostic Task Force (2) and/or large PCD Centres, we agree that HSVA has an important role that is not recognized by the American Thoracic Society (ATS) PCD Diagnostic Guideline (3). This risks a large proportion of false-negative “missed” diagnoses and a sizable number of false-positive cases; we make additional important observations.

Primary ciliary dyskinesia (PCD) is a rare heterogeneous disorder, usually inherited as an autosomal recessive condition but X-linked inheritance is also described. Abnormal ciliary function in childhood leads to neonatal respiratory distress in term infants, persistent wet cough, bronchiectasis, chronic rhinosinusitis, and hearing impairment; approximately 50% of patients have situs inversus. There is a paucity of evidence for treating PCD, hence consensus guidelines are predominantly influenced by knowledge from cystic fibrosis (CF). Extrapolation of evidence from other diseases is inappropriate since differences in pathophysiology, morbidity and prognosis risk treatment failure and lack of adherence. Areas covered: Review authors searched PubMed and Cochrane databases for publications relating to management of children with PCD. Because of the paucity of data, we emphasise the need for well-designed clinical trials with PCD patients rather than reliance on evidence from other diseases. Expert commentary: The evidence for treatment of PCD is poor, and management is often extrapolated from studies of patients with CF or chronic rhinosinusitis. However, much work is underway to improve the situation and international consortia and networks are conducting well-designed projects to inform the management of children with PCD.

BackgroundPrimary ciliary dyskinesia (PCD), a genetically heterogeneous condition enriched in some consanguineous populations, results from recessive mutations affecting cilia biogenesis and motility. Currently, diagnosis requires multiple expert tests.MethodsThe diagnostic utility of multigene panel next-generation sequencing (NGS) was evaluated in 161 unrelated families from multiple population ancestries.ResultsMost (82%) families had affected individuals with biallelic or hemizygous (75%) or single (7%) pathogenic causal alleles in known PCD genes. Loss-of-function alleles dominate (73% frameshift, stop-gain, splice site), most (58%) being homozygous, even in non-consanguineous families. Although 57% (88) of the total 155 diagnostic disease variants were novel, recurrent mutations and mutated genes were detected. These differed markedly between white European (52% of families carry DNAH5 or DNAH11 mutations), Arab (42% of families carry CCDC39 or CCDC40 mutations) and South Asian (single LRRC6 or CCDC103 mutations carried in 36% of families) patients, revealing a striking genetic stratification according to population of origin in PCD. Genetics facilitated successful diagnosis of 81% of families with normal or inconclusive ultrastructure and 67% missing prior ultrastructure results.ConclusionsThis study shows the added value of high-throughput targeted NGS in expediting PCD diagnosis. Therefore, there is potential significant patient benefit in wider and/or earlier implementation of genetic screening.

Primary ciliary dyskinesia (PCD) generally causes symptoms from the first weeks of life, but diagnosis is usually delayed for years or can be missed altogether. Referral for diagnostic testing is often late because key symptoms, such as wet cough, chronic rhinitis and recurrent upper and lower respiratory tract infection, are non-specific. An international survey of patients reported that 37% had >40 visits to medical professionals due to PCD-related symptoms before being referred for diagnostic testing [1]. Approximately 50% of children with PCD have situs inversus, a rare condition in the general population, and it is therefore not surprising that these patients are investigated earlier. A European survey found that age of diagnosis was at 3.5 years in those with situs inversus and 5.8 years in children with normal situs [2]. Assuming a prevalence of 1 in 10 000 [3], we expect ∼1180 diagnosed children in England (childhood population ∼11.8 million); however, there are currently only ∼340 children in the National Paediatric PCD Service. This highlights a huge proportion of undiagnosed patients even in a country with a national PCD service [4]. This is in stark contrast to cystic fibrosis (CF) where neonatal screening programmes ensure that diagnosis occurs in early infancy in many countries, with positive impact on clinical outcome [5]. Young children with PCD have similarly impaired forced expiratory volume in 1 s to children with CF [6], and require multidisciplinary treatment. Early diagnosis facilitates a management plan, including regular airway clearance physiotherapy, surveillance for airway pathogens with treatment of respiratory exacerbations, genetic counselling for families, audiology monitoring and management of conductive hearing loss [7, 8]. We expect that early diagnosis would delay respiratory decline and ensure specialist treatment of ear, hearing and nasal issues, thereby optimising health, psychological, social and educational outcomes. There is no single gold standard test for PCD diagnosis. Presently, the diagnosis is made in patients with a compatible medical history following a demanding combination of tests including nasal nitric oxide (nNO), high-speed video microscopy, transmission electron microscopy, genetics, and culture of respiratory epithelial cells [7, 9–12]. These tests are costly and need experienced staff using sophisticated equipment, hence testing is restricted to reference centres which may be geographically distant from the patient. Identifying the correct patients for testing is therefore important and screening tools are needed. Although individual symptoms are non-specific, the pattern of symptoms is often characteristic. A typical history might include neonatal respiratory distress in an infant with no risk factors, a daily wet cough starting in early infancy, recurrent chest infections, persistent rhinitis and serous otitis media. Screening tools (e.g. PICADAR) to identify patients based on their clinical history are helpful but require a history that might not yet have evolved in young infants [13, 14].

Primary ciliary dyskinesia (PCD) is a rare, heterogeneous genetic disorder where impaired mucociliary clearance is caused by dysfunctional motile cilia leading to bronchiectasis. There is limited evidence characterising the nutritional status of children with PCD, although lower body mass index (BMI) z-score has been associated with worse lung function (FEVAll children (n = 43) with PCD, aged16 years, from a single tertiary centre were prospectively enrolled. Information on clinical phenotype and nutritional status including bioelectrical impedance spectroscopy (BIS) phase-angle was collected.There was a weak positive association between height-for-age z-score (HAZ) and FEVWe have characterised the nutritional phenotype of a cohort of children with PCD. Monitoring vitamin D levels is important in PCD patients. There is a weak association between lung function and nutritional status, and measures of BIS phase-angle. The use of BIS phase-angle may allow for early identification of at risk children and may therefore be of benefit for nutritional assessments in the clinical setting. These findings will help inform a future nutritional intervention strategy in children with PCD.

Primary ciliary dyskinesia (PCD) is a rare heterogenous condition that causes progressive suppurative lung disease, chronic rhinosinusitis, chronic otitis media, infertility and abnormal situs. ‘Better Experimental Approaches to Treat Primary Ciliary Dyskinesia’ (BEAT-PCD) is a network of scientists and clinicians coordinating research from basic science through to clinical care with the intention of developing treatments and diagnostics that lead to improved long-term outcomes for patients. BEAT-PCD activities are supported by EU funded COST Action (BM1407). The second BEAT-PCD conference, and third PCD training school were held jointly in April 2017 in Valencia, Spain. Presentations and workshops focussed on advancing the knowledge and skills relating to PCD in: basic science, epidemiology, diagnostic testing, clinical management and clinical trials. The multidisciplinary conference provided an interactive platform for exchanging ideas through a program of lectures, poster presentations, breakout sessions and workshops. Three working groups met to plan consensus statements. Progress with BEAT-PCD projects was shared and new collaborations were fostered. In this report, we summarize the meeting, highlighting developments made during the meeting. Electronic supplementary material The online version of this article (10.1186/s12919-018-0098-9) contains supplementary material, which is available to authorized users.

RationalePrimary ciliary dyskinesia is a genetically heterogeneous inherited condition characterised by progressive lung disease arising from abnormal cilia function. Approximately half of patients have situs inversus. The estimated prevalence of primary ciliary dyskinesia in the UK South Asian population is 1:2265. Early, accurate diagnosis is key to implementing appropriate management but clinical diagnostic tests can be equivocal.ObjectivesTo determine the importance of genetic screening for primary ciliary dyskinesia in a UK South Asian population with a typical clinical phenotype, where standard testing is inconclusive.MethodsNext-generation sequencing was used to screen 86 South Asian patients who had a clinical history consistent with primary ciliary dyskinesia. The effect of a CCDC103 p.His154Pro missense variant compared with other dynein arm-associated gene mutations on diagnostic/phenotypic variability was tested. CCDC103 p.His154Pro variant pathogenicity was assessed by oligomerisation assay.ResultsSixteen of 86 (19%) patients carried a homozygous CCDC103 p.His154Pro mutation which was found to disrupt protein oligomerisation. Variable diagnostic test results were obtained including normal nasal nitric oxide levels, normal ciliary beat pattern and frequency and a spectrum of partial and normal dynein arm retention. Fifteen (94%) patients or their sibling(s) had situs inversus suggesting CCDC103 p.His154Pro patients without situs inversus are missed.ConclusionsThe CCDC103 p.His154Pro mutation is more prevalent than previously thought in the South Asian community and causes primary ciliary dyskinesia that can be difficult to diagnose using pathology-based clinical tests. Genetic testing is critical when there is a strong clinical phenotype with inconclusive standard diagnostic tests.

Non-typeable

International audience; The diagnosis of primary ciliary dyskinesia is often confirmed with standard, albeit complex and expensive, tests. In many cases, however, the diagnosis remains difficult despite the array of sophisticated diagnostic tests. There is no “gold standard” reference test. Hence, a Task Force supported by the European Respiratory Society has developed this guideline to provide evidence-based recommendations on diagnostic testing, especially in light of new developments in such tests, and the need for robust diagnoses of patients who might enter randomised controlled trials of treatments. The guideline is based on pre-defined questions relevant for clinical care, a systematic review of the literature, and assessment of the evidence using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. It focuses on clinical presentation, nasal nitric oxide, analysis of ciliary beat frequency and pattern by high-speed video-microscopy analysis, transmission electron microscopy, genotyping and immunofluorescence. It then used a modified Delphi survey to develop an algorithm for the use of diagnostic tests to definitively confirm and exclude the diagnosis of primary ciliary dyskinesia; and to provide advice when the diagnosis was not conclusive. Finally, this guideline proposes a set of quality criteria for future research on the validity of diagnostic methods for primary ciliary dyskinesia.

Nasal nitric oxide (nNO) concentrations are low in patients with primary ciliary dyskinesia (PCD) providing a noninvasive screening test.We conducted a systematic review of the literature to examine the utility of nNO in screening for PCD, in particular 1) different respiratory manoeuvres during sampling (velum closure, tidal breathing, etc.), 2) accuracy in screening young/uncooperative children, 3) stationary versus portable analysers, and 4) nNO in “atypical” PCD.96 papers were assessed according to modified PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria and 22 were included in this review.Meta-analysis of 11 studies comparing nNO during a velum closure breath hold gave a mean±sd nNO of 19.4±18.6 nL·min-1 in PCD (n = 478) and 265.0±118.9 nL·min-1 in healthy controls (n = 338). Weighted mean difference for PCD versus healthy controls was 231.1 nL·min-1 (95% CI 193.3–268.9; n = 338) and 114.1 nL·min-1 (95% CI 101.5–126.8; n = 415) for PCD versus cystic fibrosis. Five studies of nNO measurement during tidal breathing demonstrated that this is an acceptable manoeuvre in young children where velum closure is not possible, but the discriminatory value was reduced. Four small studies of portable NO analysers suggest these are reliable tools for screening for PCD. However, nNO must be interpreted alongside clinical suspicion. Future studies should focus on standardising sampling techniques and reporting.

Primary ciliary dyskinesia (PCD) is a heterogeneous autosomal recessive condition affecting around 1:15,000. In people with PCD, microscopic motile cilia do not move normally resulting in impaired clearance of mucus and debris leading to repeated sinopulmonary infection. If diagnosis is delayed, permanent bronchiectasis and deterioration of lung function occurs. Other complications associated with PCD include congenital heart disease, hearing impairment and infertility. A small number of longitudinal studies suggest that lung function deteriorates before diagnosis of PCD but may stabilise following diagnosis with subsequent specialist management. Early diagnosis is therefore essential, but for a number of reasons referral for diagnostic testing is often delayed until older childhood or even adulthood. Functional diagnostic tests for PCD are expensive, time consuming and require specialist equipment and scientists. In the last few years, there have been considerable developments to identify genes associated with PCD, currently enabling 65% of patients to be identified by bi-allelic mutations. The rapid identification of new genes continues. This review will consider the evidence that early diagnosis of PCD is beneficial. It will review the recent advances in identification of PCD-associated genes and will discuss the role of genetic testing in PCD. It will then consider whether screening for PCD antenatally or in the new born is likely to become a feasible and acceptable for this rare disease.

BACKGROUND: We report on a follow-up clinical and serological investigation of 274 children who received seasonal influenza vaccine (trivalent inactivated vaccine [TIV]) 1 year after receipt of either AS03(B)-adjuvanted subunit or whole virus monovalent A(H1N1)pdm09 vaccine and describe the antibody responses to the H3N2 A/Perth/16/2009 and B/Brisbane/60/2008 components of TIV. METHODS: Vaccine responses were analyzed using hemagglutination inhibition (HAI) assays. In children aged 3 years, responses to the H3 and B components of TIV were similar between vaccine groups. Sera taken before and after the pandemic vaccine were also analyzed by HAI using A/Perth/16/2009 virus. This analysis showed that 11.1% of children receiving the AS03(B)-adjuvanted vaccine but only 1.4% in the nonadjuvanted group had a 4-fold rise to A/Perth/16/2009. CONCLUSION: AS03B-adjuvanted A(H1N1)pdm09 influenza vaccine generates a cross-reactive antibody response to H3N2 in children and enhances responses to heterologous subtypes in children aged

PYRRO-C3D is a cephalosporin-3-diazeniumdiolate nitric oxide (NO) donor prodrug designed to selectively deliver NO to bacterial infection sites. The objective of this study was to assess the activity of PYRRO-C3D against nontypeable Haemophilus influenzae (NTHi) biofilms and examine the role of NO in reducing biofilm-associated antibiotic tolerance. The activity of PYRRO-C3D on in vitro NTHi biofilms was assessed through CFU enumeration and confocal microscopy. NO release measurements were performed using an ISO-NO probe. NTHi biofilms grown on primary ciliated respiratory epithelia at an air-liquid interface were used to investigate the effects of PYRRO-C3D in the presence of host tissue. Label-free liquid chromatography-mass spectrometry (LC/MS) proteomic analyses were performed to identify differentially expressed proteins following NO treatment. PYRRO-C3D specifically released NO in the presence of NTHi, while no evidence of spontaneous NO release was observed when the compound was exposed to primary epithelial cells. NTHi lacking β-lactamase activity failed to trigger NO release. Treatment significantly increased the susceptibility of in vitro NTHi biofilms to azithromycin, causing a log fold reduction (10-fold reduction or 1-log-unit reduction) in viability ( P < 0.05) relative to azithromycin alone. The response was more pronounced for biofilms grown on primary respiratory epithelia, where a 2-log-unit reduction was observed ( P < 0.01). Label-free proteomics showed that NO increased expression of 16 proteins involved in metabolic and transcriptional/translational functions. NO release from PYRRO-C3D enhances the efficacy of azithromycin against NTHi biofilms, putatively via modulation of NTHi metabolic activity. Adjunctive therapy with NO mediated through PYRRO-C3D represents a promising approach for reducing biofilm-associated antibiotic tolerance.

Diagnosis of primary ciliary dyskinesia (PCD) lacks a “gold standard” test and is therefore based on combinations of tests including nasal nitric oxide (nNO), high-speed video microscopy analysis (HSVMA), genotyping and transmission electron microscopy (TEM). There are few published data on the accuracy of this approach. Using prospectively collected data from 654 consecutive patients referred for PCD diagnostics we calculated sensitivity and specificity for individual and combination testing strategies. Not all patients underwent all tests. HSVMA had excellent sensitivity and specificity (100% and 93%, respectively). TEM was 100% specific, but 21% of PCD patients had normal ultrastructure. nNO (30 nL·min−1 cut-off) had good sensitivity and specificity (91% and 96%, respectively). Simultaneous testing using HSVMA and TEM was 100% sensitive and 92% specific. In conclusion, combination testing was found to be a highly accurate approach for diagnosing PCD. HSVMA alone has excellent accuracy, but requires significant expertise, and repeated sampling or cell culture is often needed. TEM alone is specific but misses 21% of cases. nNO (≤30 nL·min−1) contributes well to the diagnostic process. In isolation nNO screening at this cut-off would miss ∼10% of cases, but in combination with HSVMA could reduce unnecessary further testing. Standardisation of testing between centres is a future priority., Combination testing in PCD diagnosis remains the most accurate approach, but standardisation is needed http://ow.ly/TLEDu

Symptoms of primary ciliary dyskinesia (PCD) are nonspecific and guidance on whom to refer for testing is limited. Diagnostic tests for PCD are highly specialised, requiring expensive equipment and experienced PCD scientists. This study aims to develop a practical clinical diagnostic tool to identify patients requiring testing. Patients consecutively referred for testing were studied. Information readily obtained from patient history was correlated with diagnostic outcome. Using logistic regression, the predictive performance of the best model was tested by receiver operating characteristic curve analyses. The model was simplified into a practical tool (PICADAR) and externally validated in a second diagnostic centre. Of 641 referrals with a definitive diagnostic outcome, 75 (12%) were positive. PICADAR applies to patients with persistent wet cough and has seven predictive parameters: full-term gestation, neonatal chest symptoms, neonatal intensive care admittance, chronic rhinitis, ear symptoms, situs inversus and congenital cardiac defect. Sensitivity and specificity of the tool were 0.90 and 0.75 for a cut-off score of 5 points. Area under the curve for the internally and externally validated tool was 0.91 and 0.87, respectively. PICADAR represents a simple diagnostic clinical prediction rule with good accuracy and validity, ready for testing in respiratory centres referring to PCD centres., PICADAR is a simple diagnostic prediction tool for PCD with good accuracy and validity that is now ready for testing http://ow.ly/X6y9s

Two doses of AS03B-adjuvanted pandemic influenza vaccine may be sufficient to maintain seroprotection across 2 influenza seasons. Administration of trivalent influenza vaccine to children who previously received 2 doses of pandemic influenza vaccine is safe and is immunogenic for the H1N1 strain., Background. We investigated antibody persistence in children 1 year after 2 doses of either an AS03B-adjuvanted split-virion or nonadjuvanted whole-virion monovalent pandemic influenza vaccine and assessed the immunogenicity and reactogenicity of a subsequent dose of trivalent influenza vaccine (TIV). Methods. Children previously immunized at age 6 months to 12 years in the original study were invited to participate. After a blood sample was obtained to assess persistence of antibody against swine influenza A/H1N1(2009) pandemic influenza, children received 1 dose of 2010/2011 TIV, reactogenicity data were collected for 7 days, and another blood sample was obtained 21 days after vaccination. Results. Of 323 children recruited, 302 received TIV. Antibody persistence (defined as microneutralization [MN] titer ≥1:40) 1 year after initial vaccination was significantly higher in the AS03B-adjuvanted compared with the whole-virion vaccine group, 100% (95% confidence interval [CI], 94.1%–100%) vs 32.4% (95% CI, 21.5%–44.8%) in children immunized

Chronic Obstructive Pulmonary Disease (COPD) has a high mortality. Many indices have been developed to classify disease severity including the 2007 and 2011 GOLD classification and BODE index. However, no study has compared the prediction of mortality by those indices. This is an observational study of 96 patients with COPD and followed prospectively for a median of 60 months. We performed at baseline pulmonary function tests, 6-minute walking test, dyspnea scale mMRC, anthropometric and questionnaire measures of exacerbations. BODE index and GOLD 2007 and GOLD 2011 classification was calculated. The capacity of all indices to predict mortality was compared using Cox proportional hazard analysis and Kaplan Meier survival cruves. A total of 55 men and 41 women were studied, of whom 50% died during a follow-up time mean of 69 +/- 37 months. The mean FEV1 was 27% +/- 5%. Statistically significant associations were observed between mortality and BODE index (p = 0.024) and male sex (p = 0.021). Cox regression analysisshowed that the only statistically significant association was with BODE (p=0,037; IC: 95% 1,024-2,17). The Kaplan-Meier curves for BODE, 2007 GOLD and GOLD ABCD were calculated and are The BODE index predicts all cause mortality better than the old GOLD classification based on FEV1 and the new ABCD grading . We also observed that patients classified as GOLD B has higher mortality than those classified as GOLD C.

Robust diagnosis of primary ciliary dyskinesia (PCD) is important if patients are to receive appropriate specialist management before irreversible deterioration of lung function occurs. Early diagnosis also enables patients and their families to receive appropriate genetic counseling, disease-specific management of ear and rhino-sinus disease, and screening for PCD-associated problems (e.g., cardiac problems) (1, 2). The association of extremely low levels of nasal nitric oxide (nNO) in PCD has been recognized for over 15 years, and measurement of nNO is increasingly used as a screening test for PCD in Europe (1). The manuscript by Leigh and coworkers in this edition of AnnalsATS (3) provides an important advance in the use of nNO for clinical and research purposes. Their data confirm that nNO is a reliable investigation for PCD in the North American population and setting, including identification of “atypical” patients with PCD who might otherwise be missed due to normal ciliary ultrastructure. The authors provide evidence that a standardized protocol using different NO analyzers can be used to reliably differentiate patients with PCD from patients without PCD and from healthy children, in geographically dispersed centers. They have additionally developed cutoff values using data from their large study population, which can now be validated in other populations. There is no “gold standard” diagnostic test to identify all PCD phenotypes, and diagnostic workup requires access to a number of specialist investigations. Previously, ciliary ultrastructure analyzed by electron microscopy (EM) was considered diagnostic, but there is an increasing literature on normal ciliary ultrastructure, at EM resolution, in PCD. This indicates that PCD will be missed in centers where diagnosis depends solely on EM (2, 4). It is also recognized that certain EM defects previously considered diagnostic might on occasion represent secondary changes that resolve on repeat testing (4, 5). In Europe, assessment of ciliary beat frequency (CBF) and pattern (CBP) by high-resolution, high-speed video microscopy (HSVm) is recommended as a functional test for PCD (1, 6). If HSVm analysis is abnormal, re-differentiation of basal epithelial cells at an air–liquid interface (ALI) in cell culture enables reassessment of ciliary function and ultrastructure to differentiate primary from secondary dyskinesia (1). Alternatively, immunoflorescent (IF) staining of ciliary proteins can support diagnosis of PCD (7). EM, HSVm, ALI-culture, and IF all require a high degree of expertise in addition to expensive equipment and infrastructure. These techniques are therefore restricted to a few highly specialized centers, limiting easy access to diagnostic testing (8). Diagnosis supported by bi-allelic mutations in genes known to be associated with PCD is promising; currently genotyping detects only 50–65% of patients (2), but as new genes are rapidly identified this will become increasingly sensitive. The evidence provided by Leigh and coleagues (3) is therefore to be welcomed by clinicians, researchers, and in particular families who are unable to travel to a highly specialized center. It is to be hoped that the U.S. Food and Drug Administration and other regulatory authorities will approve nNO analyzers for clinical use given the evidence that nNO is a reliable screening test for PCD and that valid measurements can be taken at sites geographically distant from a diagnostic center using standardized protocols. Leigh and coworkers report a cutoff value for nNO of 77 nL/min providing sensitivity of 0.98 and specificity greater than 0.999. This cutoff value was validated across six other sites, identifying 70 of the 71 (98.6%) participants with confirmed PCD. A previous study used a cutoff for nNO of 105 parts per billion and reported a specificity of 88%, a sensitivity of 100%, and a positive predictive value of 89% for correctly diagnosing PCD (9). While there are now substantial data to demonstrate that nNO measurement is helpful in guiding the diagnostic pathway, we need to recognize limitations of this measurement. Standardized methods (10) to measure nNO are not appropriate for younger children, precisely the age group that need targeting for diagnostic measurement. Tidal measurements allow levels to be measured in young infants, although there is limited experience in this younger age group (1, 11, 12). Patients with other with upper and lower airway diseases have been reported to have reduced nNO levels, although usually not as low as in PCD; such diseases include cystic fibrosis, nasal polyps and chronic sinusitis. A few groups have recently reported normal levels of nasal NO in a minority of patients with PCD (1, 11, 13). These studies highlight that patients with a history strongly suggestive of PCD should not be excluded from further diagnostic evaluation on the basis of nNO, and also that, while providing an excellent screening test, nNO is not diagnostic and low levels should trigger referral to a highly specialized diagnostic center. A priority for researchers is to understand the cause of the extraordinarily low nNO observed in PCD (14). From a clinical perspective, the next hurdle to overcome is the lack of regulatory approvals of nNO analyzers for PCD diagnosis, as well as the cost and therefore availability of devices. Until recently, the only commercially available analyzers for measuring nNO were nonportable desktop analyzers, which are extremely expensive. More reasonably priced portable machines (15) are now available, although they are not yet fully validated nor approved for clinical use. Manufacturers should be encouraged to develop, validate, and seek approvals for user-friendly, reasonably priced nNO analyzers. This will lead to a step change in the diagnosis of PCD by reliably identifying patients for referral to specialist diagnostic centers.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Non-typeable Haemophilus influenzae (NTHi) is the most common pathogen in primary ciliary dyskinesia (PCD) patients. We hypothesised that abnormal ciliary motility and low airway nitric oxide (NO) levels on airway epithelial cells from PCD patients might be permissive for NTHi colonisation and biofilm development. We used a primary epithelial cell co-culture model to investigate NTHi infection. Primary airway epithelial cells from PCD and non-PCD patients were differentiated to ciliation using an air–liquid interface culture and then co-cultured with NTHi. NTHi adherence was greater on PCD epithelial cells compared to non-PCD cells ( p

Primary ciliary dyskinesia (PCD) is a genetic disease characterized by abnormalities in ciliary function, leading to compromised airway clearance and chronic bacterial infection of the upper and lower airways. The compositions of these infections and the relationships between their characteristics and disease presentation are poorly defined. We describe here the first systematic culture-independent evaluation of lower airway bacteriology in PCD. Thirty-three airway samples (26 from sputum, 7 from bronchoalveolar lavage [BAL] fluid) were collected from 24 PCD patients aged 4 to 73 years. 16S rRNA quantitative PCR and pyrosequencing were used to determine the bacterial loads and community compositions of the samples. Bacterial loads, which ranged from 1.3 × 10 4 to 5.2 × 10 9 CFU/ml, were positively correlated with age ( P = 0.002) but not lung function. An analysis of ∼7,000 16S rRNA sequences per sample identified bacterial species belonging to 128 genera. The concurrently collected paired samples showed high bacterial community similarity. The mean relative abundance of the dominant genera was 64.5% (standard deviation [SD], 24.5), including taxa reported through standard diagnostic microbiology (members of the genera Pseudomonas , Haemophilus , and Streptococcus ) and those requiring specific ex vivo growth conditions (members of the genera Prevotella and Porphyromonas ). The significant correlations observed included a positive relationship between Pseudomonas aeruginosa relative abundance and age and a negative relationship between P. aeruginosa relative abundance and lung function. Members of the genus Ralstonia were also found to contribute substantially to the bacterial communities in a number of patients. Follow-up samples from a subset of patients revealed high levels of bacterial community temporal stability. The detailed microbiological characterization presented here provides a basis for the reassessment of the clinical management of PCD airway infections.

Background Nasal nitric oxide (nNO) levels are very low in primary ciliary dyskinesia (PCD) and it is used as a screening test. Methods We assessed the reliability and usability of a hand-held analyser in comparison to a stationary nitric oxide (NO) analyser in 50 participants (15 healthy, 13 PCD, 22 other respiratory diseases; age 6–79 years). Nasal NO was measured using a stationary NO analyser during a breath-holding maneuver, and using a hand-held analyser during tidal breathing, sampling at 2 ml/sec or 5 ml/sec. The three methods were compared for their specificity and sensitivity as a screen for PCD, their success rate in different age groups, within subject repeatability and acceptability. Correlation between methods was assessed. Results Valid nNO measurements were obtained in 94% of participants using the stationary analyser, 96% using the hand-held analyser at 5 ml/sec and 76% at 2 ml/sec. The hand-held device at 5 ml/sec had excellent sensitivity and specificity as a screening test for PCD during tidal breathing (cut-off of 30 nL/min,100% sensitivity, >95% specificity). The cut-off using the stationary analyser during breath-hold was 38 nL/min (100% sensitivity, 95% specificity). The stationary and hand-held analyser (5 ml/sec) showed reasonable within-subject repeatability(% coefficient of variation = 15). Conclusion The hand-held NO analyser provides a promising screening tool for PCD.

Nitric oxide is continually synthesized in the respiratory epithelium and is upregulated in response to infection or inflammation. Primary ciliary dyskinesia is characterized by recurrent sinopulmonary infections due to impaired mucociliary clearance. Despite chronic infections, nasal nitric oxide in such patients is markedly reduced and is used as a screening test for this condition. These low levels were first described over 15 years ago but the underlying mechanisms have yet to be fully elucidated. We review epithelial nitric oxide synthesis, release and measurement in the upper airways with particular reference to primary ciliary dyskinesia. The key hypotheses that have been proposed to explain the low levels in this condition are explored and the potential benefits of augmenting airway nitric oxide levels are considered. Further work in these patients clarifying both whether the respiratory epithelium is able to biosynthesise normal levels of nitric oxide and the role played by abnormalities in the anatomy of the paranasal sinuses is essential. While nitric oxide augmentation is unlikely to be beneficial in common primary ciliary dyskinesia phenotypes, it has potential in the treatment of secondary dyskinesias and may also improve treatment of bacterial infections, particularly where biofilms are implicated.

Introduction: Pandemic influenza A H1N1 infections occurred worldwide from 2009. Children were particularly vulnerable. Novel vaccines were used during the pandemic. Objective: To assess the persistence of antibody to H1N1 influenza 1 year after children aged 6 months to 12 years had been immunised with two doses of either a non-adjuvanted whole-virion H1N1 influenza vaccine or an AS03 B-adjuvanted split-virion H1N1 influenza vaccine; and also to assess the immunogenicity and reactogenicity in this population of a single dose of 2010-11 trivalent seasonal influenza vaccine. Design: Multicentre, open-label, follow-on from randomised, head-to-head trial. Setting: Five UK sites (Southampton, Oxford, Bristol, London and Exeter). Participants: Children who completed last year's head-to-head randomised study were invited to participate. Children who had subsequently received a further dose of H1N1 vaccine, or who had already received a dose of 2010-11 trivalent seasonal influenza vaccine, were excluded. Interventions: In the previous study, children were randomised (in a 1: 1 ratio) to receive two doses, 21 days apart, of either a non-adjuvanted whole-virion H1N1 influenza vaccine or an AS03 B-adjuvanted split-virion H1N1 influenza vaccine. In this follow-on study, a blood sample was taken to assess the persistence of antibody 1 year later, followed by administration of one 0.5 ml-dose of trivalent seasonal influenza vaccine. A second blood sample was taken 3 weeks later. Main outcome measures: Comparison between vaccines of the percentage of participants with a microneutralisation (MN) titre ≥ 1: 40 and a haemagglutination titre ≥ 1: 32, 1 year after vaccination. Immunogenicity of the trivalent seasonal influenza vaccine was assessed 3 weeks after vaccination by both the MN and the haemagglutination inhibition (HI) titres. Reactogenicity data were recorded for 7 days after vaccination. Results: A total of 323 children were enrolled and 318 were included in the analysis of the persistence of antibody. One year after receipt of whole-virion vaccine, the MN titre was ≥ 1: 40 in 32.4% of those vaccinated when < 3 years old and in 65.9% of those vaccinated when ≥ 3 years old; the HI titre was ≥ 1: 32 in 63.2% and 79.1% of children in the respective age groups. One year after receipt of the adjuvanted vaccine, the MN titre was ≥ 1: 40 in 100% of those vaccinated when < 3 years old and in 96.9% of those vaccinated when ≥ 3 years old; the HI titre was ≥ 1: 32 in 98.4% and 96.9% of children in the respective age groups. Three hundred and two children were given trivalent seasonal influenza vaccination. Three weeks later, sera were obtained from 282 children; 100% had an MN titre ≥ 1: 40 and HI titre ≥ 1: 32. Trivalent seasonal influenza vaccine was well tolerated, although in children < 5 years old, fever ≥ 38 °C was reported in 13.6% of those who had previously received whole-virion vaccine, and in 18.3% of those who had received adjuvanted vaccine. Conclusions: Nearly all children who received two doses of AS03 B-adjuvanted split-virion pandemic H1N1 influenza vaccine had titres of antibody deemed protective (HI titre ≥ 1: 32, MN titre ≥ 1: 40) 1 year later. Children who received two doses of whole-virion vaccine had lower titres, although many were above the putative protective thresholds. One year after either pandemic vaccine, the 2010-11 trivalent seasonal influenza vaccine produced a marked serological response to the H1N1 component of the vaccine and was well tolerated. We propose to investigate whether or not previous receipt of monovalent influenza vaccines affected serological response to the H3N2 and B components of the 2010-11 seasonal influenza vaccine, using stored sera. Trial registration: ClinicalTrials.gov NCT01239537. Funding: The National Institute for Health Research Health Technology Assessment programme. © Queen's Printer and Controller of HMSO 2011.

In 2009, 943 children aged 6 months to 10 years were randomised to receive two doses of an oil-in water AS03B-adjuvanted split virion or a non-adjuvanted whole virion H1N1 (2009) vaccine. The large numbers allowed investigation of possible predictors of immune response and reactogenicity. We used regression analysis to examine the effect of variables including past receipt of seasonal vaccine, antipyretics post-vaccination, interval between doses and pre-existing antibodies to H1N1 (2009) on immunogenicity. We also examined the relationship between immunogenicity and reactogenicity and whether prior infection or underlying conditions affected reactogenicity. For both vaccines, haemagglutination-inhibition titres were 60% higher in children with fever ≥38. °C after vaccination and 29% lower in those previously given seasonal vaccine. Early use of antipyretics did not affect immunogenicity. Post-vaccination titres were higher with longer intervals between doses and in those with evidence of prior infection, but reactogenicity in the latter was unaffected. In the adjuvanted vaccine group, reactions were more common in children with atopy. Both vaccines were safe and immunogenic in those with prior infection. Reduction in the interval between doses for earlier protection would be at the cost of reduced immunogenicity. The effect of seasonal vaccine on immunogenicity merits further investigation. © 2011 Elsevier Ltd.

Background: Children are a priority for vaccination in an influenza pandemic, but safety and immunogenicity data for new-generation adjuvanted and whole-virion vaccines are limited. Objectives: Immunogenicity •How does the percentage of children aged 6 months to 12 years of age with a fourfold rise in microneutralisation titres between the prevaccination sample and the sample taken 3 weeks after completion of a two-dose course of the non-adjuvanted, whole-virion vaccine and the AS03B-adjuvanted split-virion vaccine compare? •How does the percentage of children aged 6 months to 12 years of age with haemagglutination inhibition titres of ? 1 : 32 3 weeks after completion of a two-dose course of the non-adjuvanted, whole-virion vaccine and the AS03B-adjuvanted split-virion vaccine compare? •How does the percentage of children aged 6 months to 12 years of age with a fourfold rise in haemagglutination inhibition titres between the prevaccination sample and the sample taken 3 weeks after completion of a two-dose course of the non-adjuvanted, whole-virion vaccine and the AS03B-adjuvanted split-virion vaccine compare? •What is the geometric mean fold rise in haemagglutination inhibition titres from baseline to 3 weeks after two doses of the non-adjuvanted, whole-virion vaccine and the AS03B-adjuvanted split-virion vaccine? •What is the geometric mean haemagglutination inhibition titre 3 weeks after two doses of the non-adjuvanted, whole-virion vaccine and the AS03B-adjuvanted split-virion vaccine? Reactogenicity •How does the percentage of children aged 6 months to 12 years of age experiencing fever and local reactions within the 7 days following each dose of the non-adjuvanted, whole-virion and the AS03B-adjuvanted split-virion vaccines compare? •What percentage of children aged 6 months to 12 years of age experience non-febrile systemic reactions within the 7 days following each dose of the non-adjuvanted, whole-virion and the AS03B-adjuvanted split-virion vaccine? Methods: The safety, reactogenicity and immunogenicity of a tocopherol/oil-in-water emulsion-adjuvanted (AS03B) egg culture-derived split-virion H1N1 vaccine and a non-adjuvanted cell culture-derived whole-virion vaccine, given as a two-dose schedule, 21 days apart, were compared in a randomised, open-label trial of children aged 6 months to 12 years of age. Local reactions and systemic symptoms were collected for 1 week post immunisation, and serum was collected at baseline and after the second dose. Results: Among 937 children receiving vaccine, per-protocol seroconversion rates were higher after the AS03B-adjuvanted vaccine than after the whole-virion vaccine (98.2% vs 80.1% in children 38.0°C in those under 5 years of age (8.9% vs 22.4%). Conclusion: In this first direct comparison of an AS03B-adjuvanted split-virion vaccine versus whole-virion non-adjuvanted H1N1 vaccine, the adjuvanted vaccine – while reactogenic – was more immunogenic, especially in younger children, indicating the potential for improved immunogenicity of influenza vaccines in this age group.

OBJECTIVES: To compare the safety, reactogenicity, and immunogenicity of an adjuvanted split virion H1N1 vaccine and a non-adjuvanted whole virion vaccine used in the pandemic immunisation programme in the United Kingdom. DESIGN: Open label, randomised, parallel group, phase II study. SETTING: Five UK centres (Oxford, Southampton, Bristol, Exeter, and London). PARTICIPANTS: Children aged 6 months to less than 13 years for whom a parent or guardian had provided written informed consent and who were able to comply with study procedures were eligible. Those with laboratory confirmed pandemic H1N1 influenza or clinically diagnosed disease meriting antiviral treatment, allergy to egg or any other vaccine components, or coagulation defects, or who were severely immunocompromised or had recently received blood products were excluded. Children were grouped by age: 6 months-or=1:40 from before vaccination to three weeks after the second dose). RESULTS: Seroconversion rates were higher after the adjuvanted split virion vaccine than after the whole virion vaccine, most notably in the youngest children (163 of 166 participants with paired serum samples (98.2%, 95% confidence interval 94.8% to 99.6%) v 157 of 196 (80.1%, 73.8% to 85.5%), Por=38 masculineC in those aged under 5 (24 (8.9%, 5.8% to 12.9%) v 57 (22.4%, 17.5% to 28.1%), P

Summary Background Patients with primary ciliary dyskinesia (PCD) have abnormal ciliary function and low nitric oxide levels. Nitric oxide (NO) biosynthesis is dependent on nitric oxide synthases (NOS). Cilia line the bronchial but not the alveolar epithelium. It has been hypothesised that NOS function relies on normal ciliary function and that in PCD bronchial but not alveolar NO might therefore be reduced. The aim of this study was to assess bronchial and alveolar NO levels primarily comparing healthy children to PCD and secondarily to cystic fibrosis (CF) and asthmatic children. Methods Multiple flow-rate fractional exhaled and nasal NO measurements were performed using a NIOX ® Flex NO analyser (Aerocrine, Sweden) in children with PCD ( n = 14), asthma ( n = 18), CF ( n = 12) and healthy controls ( n = 18). Alveolar and bronchial NO levels were derived using a model of pulmonary NO exchange-dynamics. Results Both the bronchial and alveolar NO were significantly lower in PCD than healthy controls (mean (SD) 264 (209) picolitres/second (pl/s) vs. 720 (514) pl/s, p = 0.024 and 1.7 (0.8) parts per billion (ppb) vs. 3.5 (1.3) ppb, p = 0.001 respectively.) In asthmatics bronchial NO was found to be significantly higher than in healthy controls and in children with CF alveolar NO was significantly lower (2100 (1935) pl/s, p = 0.045 and 2.5 (1.2) ppb, p = 0.034 respectively.) Conclusion Our findings do not support the hypothesis that NOS and ciliary function are coupled instead suggesting a more generalised mechanism for the low levels of NO seen in PCD. Our findings in CF and asthma corroborate evidence that these are diseases of the lung peripheries and bronchi respectively.

Background Patients with primary ciliary dyskinesia (PCD) have abnormal ciliary function and low nasal nitric oxide (nNO) and fractional exhaled NO (FeNO). Nitric oxide (NO) biosynthesis is dependent on nitric oxide synthases (NOS). Cilia line the bronchial but not the alveolar epithelium. It has been hypothesised that NOS function relies on normal ciliary function and that in PCD bronchial (JNO) but not alveolar (CalvNO) NO might therefore be reduced. The aim of this study was to compare JNO and CalvNO in children with PCD, cystic fibrosis (CF), asthma and healthy subjects.