Primary ciliary dyskinesia: diagnostic and phenotypic features

Accuracy of Nasal Nitric Oxide Measurement as a Diagnostic Test for Primary Ciliary Dyskinesia. A Systematic Review and Meta-analysis

RATIONALE

Primary ciliary dyskinesia (PCD) is a rare disorder causing chronic otosinopulmonary disease, generally diagnosed through evaluation of respiratory ciliary ultrastructure and/or genetic testing. Nasal nitric oxide (nNO) measurement is used as a PCD screening test because patients with PCD have low nNO levels, but its value as a diagnostic test remains unknown.

OBJECTIVES

To perform a systematic review to assess the utility of nNO measurement (index test) as a diagnostic tool compared with the reference standard of electron microscopy (EM) evaluation of ciliary defects and/or detection of biallelic mutations in PCD genes.

DATA SOURCES

Ten databases were searched for reference sources from database inception through July 29, 2016.

DATA EXTRACTION

Study inclusion was limited to publications with rigorous nNO index testing, reference standard diagnostic testing with EM and/or genetics, and calculable diagnostic accuracy information for cooperative patients (generally >5 yr old) with high suspicion of PCD.

SYNTHESIS

Meta-analysis provided a summary estimate for sensitivity and specificity and a hierarchical summary receiver operating characteristic curve. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess study quality, and Grading of Recommendations Assessment, Development, and Evaluation was used to assess the certainty of evidence. In 12 study populations (1,344 patients comprising 514 with PCD and 830 without PCD), using a reference standard of EM alone or EM and/or genetic testing, summary sensitivity was 97.6% (92.7-99.2) and specificity was 96.0% (87.9-98.7), with a positive likelihood ratio of 24.3 (7.6-76.9), a negative likelihood ratio of 0.03 (0.01-0.08), and a diagnostic odds ratio of 956.8 (141.2-6481.5) for nNO measurements. After studies using EM alone as the reference standard were excluded, the seven studies using an extended reference standard of EM and/or genetic testing showed a summary sensitivity of nNO measurements of 96.3% (88.7-98.9) and specificity of 96.4% (85.1-99.2), with a positive likelihood ratio of 26.5 (5.9-119.1), a negative likelihood ratio of 0.04 (0.01-0.12), and a diagnostic odds ratio of 699.3 (67.4-7256.0). Certainty of the evidence was graded as moderate.

CONCLUSIONS

nNO is a sensitive and specific test for PCD in cooperative patients (generally >5 yr old) with high clinical suspicion for this disease. With a moderate level of evidence, this meta-analysis confirms that nNO testing using velum closure maneuvers has diagnostic accuracy similar to EM and/or genetic testing for PCD when cystic fibrosis is ruled out. Thus, low nNO values accompanied by an appropriate clinical phenotype could be used as a diagnostic PCD test, though EM and/or genetics will continue to provide confirmatory information.

Seeing cilia: imaging modalities for ciliary motion and clinical connections

The respiratory tract is lined with multiciliated epithelial cells that function to move mucus and trapped particles via the mucociliary transport apparatus. Genetic and acquired ciliopathies result in diminished mucociliary clearance, contributing to disease pathogenesis. Recent innovations in imaging technology have advanced our understanding of ciliary motion in health and disease states. Application of imaging modalities including transmission electron microscopy, high-speed video microscopy, and micron-optical coherence tomography could improve diagnostics and be applied for precision medicine. In this review, we provide an overview of ciliary motion, imaging modalities, and ciliopathic diseases of the respiratory system including primary ciliary dyskinesia, cystic fibrosis, chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis.

Computed tomography in adult patients with primary ciliary dyskinesia: Typical imaging findings

Objectives

Among patients with non-cystic fibrosis bronchiectasis, 1–18% have an underlying diagnosis of primary ciliary dyskinesia (PCD) and it is suspected that there is under-recognition of this disease. Our intention was to evaluate the specific features of PCD seen on computed tomography (CT) in the cohort of bronchiectasis in order to facilitate the diagnosis.

Materials and methods

One hundred and twenty-one CTs performed in patients with bronchiectasis were scored for the involvement, type, and lobar distribution of bronchiectasis, bronchial dilatation, and bronchial wall thickening. Later, associated findings such as mucus plugging, tree in bud, consolidations, ground glass opacities, interlobular thickening, intralobular lines, situs inversus, emphysema, mosaic attenuation, and atelectasis were registered. Patients with PCD (n = 46) were compared to patients with other underlying diseases (n = 75).

Results

In patients with PCD, the extent and severity of the bronchiectasis and bronchial wall thickness were significantly lower in the upper lung lobes (p<0.001-p = 0.011). The lobar distribution differed significantly with a predominance in the middle and lower lobes in patients with PCD (<0.001). Significantly more common in patients with PCD were mucous plugging (p = 0.001), tree in bud (p <0.001), atelectasis (p = 0.009), and a history of resection of a middle or lower lobe (p = 0.047). Less common were emphysematous (p = 0.003) and fibrotic (p<0.001) changes. A situs inversus (Kartagener’s Syndrome) was only seen in patients with PCD (17%, p <0.001).

Conclusion

Typical imaging features in PCD include a predominance of bronchiectasis in the middle and lower lobes, severe tree in bud pattern, mucous plugging, and atelectasis. These findings may help practitioners to identify patients with bronchiectasis in whom further work-up for PCD is called for.

Compound Heterozygous Variants in the Coiled-Coil Domain Containing 40 Gene in a Chinese Family with Primary Ciliary Dyskinesia Cause Extreme Phenotypic Diversity in Cilia Ultrastructure

Purpose: Primary ciliary dyskinesia (PCD) is a rare genetic disorder manifested with recurrent infections of respiratory tract and infertility. Mutations in more than 20 genes including the Coiled-Coil Domain Containing 40 (CCDC40) gene are associated with PCD. A Chinese proband with a clinical diagnosis of PCD was analyzed for mutations in these genes to identify the genetic basis of the disease in the family. The proband showed altered mucociliary clearance of the airways, various degree of hyperemia and edema of the mucous membrane, left/right body asymmetry, infertility and ultrastructural abnormality of cilia in both sperm and bronchioles. Methods: The DNA from the proband was analyzed for genetic variation in a subset of genes known to cause PCD using targeted next generation sequencing in order to understand the molecular and genetic basis of the PCD in present family. The result of targeted next generation sequencing has been validated by Sanger sequencing and q-PCR. Results: Targeted next-generation sequencing identified two novel mutations (c.1259delA and EX17_20 deletion) in CCDC40 gene that causes abnormal CCDC40 mRNA expression. These two novel variants cause disorganization of axoneme filaments, which resulted in reduction of sperm motility and phenotypic diversity in ultrastructure of cilia in the proband. Conclusion: These findings highlight the significance of the mutations in CCDC40 as novel candidates for genetic testing in PCD patients as well as the key role of ICSI treatment for the families affected by this ciliary dysmotility. Our findings showed that our work enriched the performance of cilia ultrastructure which were not previously reported in PCD patients.

No evidence of cholesteatoma in untreated otitis media with effusion in children with primary ciliary dyskinesia

INTRODUCTION

Primary Ciliary Dyskinesia (PCD) describes a group of inherited disorders that result in abnormal ciliary motion leading to mucous stasis. Clinical features include almost universally otitis media with effusion (OME), particularly in infants. PCD patients provide us with a cohort of patients with OME that is not treated with ventilatory tube (VT) insertion as these have been shown to result in frequent complications including chronic otorrhoea, early extrusion and persistent perforation without significant improvement to hearing in the long term. This cohort was used to investigate whether children with PCD and OME not treated with VT were predisposed to cholesteatoma formation in the setting of a paediatric quaternary referral centre.

METHODS

A retrospective chart review was performed of all the children attending a multi-disciplinary PCD clinic at a national quaternary referral centre with a diagnosis of OME. We reviewed otoscopic findings, and audiometry and tympanometry results. We assessed the children in four groups: Watchful waiting, hearing aids, VT, and VT and hearing aids.

RESULTS

One-hundred-and-one of 107 patients included in the study had a diagnosis of otitis media with effusion. No child with OME and PCD was diagnosed with a cholesteatoma during the follow up period. The only children who had insertion of a ventilatory tube were those who had the procedure prior to the formal diagnosis of PCD. We found a significant complication rate in the children with VT insertion. Hearing improved over time. The prevalence of retraction pockets in untreated OME was 1.72% (3 out of 174 ears).

CONCLUSIONS

In children with PCD, OME is an almost universal finding in younger children, but not in adolescents. The study supports the current preference to avoid VT insertion in children with PCD as it confers a significantly higher rate of complications. No cases of cholesteatoma were found in this cohort of PCD children with OME managed without VTs.

Nontuberculous mycobacterial disease in childhood - update on diagnostic approaches and treatment

Recent studies suggest that the incidence of nontuberculous mycobacterial infections in children may be increasing. Nontuberculous mycobacterial lymphadenitis, skin and soft tissue infection, and pulmonary disease each present unique challenges in relation to diagnosis and treatment. In this update, we critically review the recent literature on the epidemiology, clinical features, diagnostic approaches and treatment of nontuberculous mycobacterial disease in children. In addition, we outline key areas warranting further research.

Gas exchanges in children with cystic fibrosis or primary ciliary dyskinesia: A retrospective study

Primary ciliary dyskinesia (PCD) and cystic fibrosis (CF) both entail bronchiectasis and pulmonary impairment as measured using spirometry, during childhood. We aimed at looking whether blood gas exchanges progressed differently between CF and PCD children in a retrospective study of repeated measurements. Comparisons between groups (Wilcoxon-Mann-Whitney and Chi-squared tests) and a mixed linear model, adjusted for age, evaluated associations between diseases and PaO₂, PaCO_2, or PaO_2-PaCO₂ ratio. Among 42 PCD and 73 CF children, 62% and 59% had respectively bronchiectasis (P = 0.75). Spirometry and blood gases were similar at inclusion (PaO₂ median [IQR] PCD -1.80 [-3.40; -0.40]; CF -1.80 [-4.20; 0.60] z-scores; P = 0.72). PaO₂ and PaO₂-PaCO₂ ratio similarly and significantly decreased with age in both groups (P < 0.01) whereas PaCO₂ increased more in CF (P = 0.02) remaining within the range of normal (except for one child). To conclude, gas exchange characteristics, similarly initially impaired in PCD and CF children, tended to less deteriorate with time in PCD children who could benefit from an early diagnosis.

Primary Ciliary Dyskinesia Due to Microtubular Defects is Associated with Worse Lung Clearance Index

Purpose

Primary ciliary dyskinesia (PCD) is characterised by repeated upper and lower respiratory tract infections, neutrophilic airway inflammation and obstructive airway disease. Different ultrastructural ciliary defects may affect lung function decline to different degrees. Lung clearance index (LCI) is a marker of ventilation inhomogeneity that is raised in some but not all patients with PCD. We hypothesised that PCD patients with microtubular defects would have worse (higher) LCI than other PCD patients.

Methods

Spirometry and LCI were measured in 69 stable patients with PCD. Age at testing, age at diagnosis, ethnicity, ciliary ultrastructure, genetic screening result and any growth of Pseudomonas aeruginosa was recorded.

Results

Lung clearance index was more abnormal in PCD patients with microtubular defects (median 10.24) than those with dynein arm defects (median 8.3, p = 0.004) or normal ultrastructure (median 7.63, p = 0.0004). Age is correlated with LCI, with older patients having worse LCI values (p = 0.03, r = 0.3).

Conclusion

This study shows that cilia microtubular defects are associated with worse LCI in PCD than dynein arm defects or normal ultrastructure. The patient’s age at testing is also associated with a higher LCI. Patients at greater risk of obstructive lung disease should be considered for more aggressive management. Differences between patient groups may potentially open avenues for novel treatments.

Electronic supplementary material

The online version of this article (10.1007/s00408-018-0086-x) contains supplementary material, which is available to authorized users.

Clinical Features and Associated Likelihood of Primary Ciliary Dyskinesia in Children and Adolescents

RATIONALE

Primary ciliary dyskinesia (PCD), a genetically heterogeneous, recessive disorder of motile cilia, is associated with distinct clinical features. Diagnostic tests, including ultrastructural analysis of cilia, nasal nitric oxide measurements, and molecular testing for mutations in PCD genes, have inherent limitations.

OBJECTIVES

To define a statistically valid combination of systematically defined clinical features that strongly associates with PCD in children and adolescents.

METHODS

Investigators at seven North American sites in the Genetic Disorders of Mucociliary Clearance Consortium prospectively and systematically assessed individuals (aged 0-18 yr) referred due to high suspicion for PCD. The investigators defined specific clinical questions for the clinical report form based on expert opinion. Diagnostic testing was performed using standardized protocols and included nasal nitric oxide measurement, ciliary biopsy for ultrastructural analysis of cilia, and molecular genetic testing for PCD-associated genes. Final diagnoses were assigned as "definite PCD" (hallmark ultrastructural defects and/or two mutations in a PCD-associated gene), "probable/possible PCD" (no ultrastructural defect or genetic diagnosis, but compatible clinical features and nasal nitric oxide level in PCD range), and "other diagnosis or undefined." Criteria were developed to define early childhood clinical features on the basis of responses to multiple specific queries. Each defined feature was tested by logistic regression. Sensitivity and specificity analyses were conducted to define the most robust set of clinical features associated with PCD.

MEASUREMENTS AND MAIN RESULTS

From 534 participants 18 years of age and younger, 205 were identified as having "definite PCD" (including 164 with two mutations in a PCD-associated gene), 187 were categorized as "other diagnosis or undefined," and 142 were defined as having "probable/possible PCD." Participants with "definite PCD" were compared with the "other diagnosis or undefined" group. Four criteria-defined clinical features were statistically predictive of PCD: laterality defect; unexplained neonatal respiratory distress; early-onset, year-round nasal congestion; and early-onset, year-round wet cough (adjusted odds ratios of 7.7, 6.6, 3.4, and 3.1, respectively). The sensitivity and specificity based on the number of criteria-defined clinical features were four features, 0.21 and 0.99, respectively; three features, 0.50 and 0.96, respectively; and two features, 0.80 and 0.72, respectively.

CONCLUSIONS

Systematically defined early clinical features could help identify children, including infants, likely to have PCD. Clinical trial registered with ClinicalTrials.gov (NCT00323167).

Airway Clearance Techniques for Primary Ciliary Dyskinesia; is the Cystic Fibrosis literature portable?

Primary Ciliary Dyskinesia (PCD) is a rare inherited disease with impaired mucociliary clearance. Airway clearance techniques (ACTs) are commonly recommended for patients with PCD to facilitate mucus clearance, despite a lack of evidence in this group. Current physiotherapy practice in PCD is based on evidence extrapolated from the field of Cystic Fibrosis (CF). This paper focuses on the available evidence and outlines challenges in extrapolating evidence between the conditions for best clinical practice.

Hearing loss in children with primary ciliary dyskinesia

OBJECTIVES

To evaluate the type and severity of hearing impairment in pediatric patients with primary ciliary dyskinesia (PCD) and relate these measures to patient demographics, treatment options, and other otologic factors.

METHODS

A retrospective analysis of children with a diagnosis of PCD, Kartagener's syndrome, or situs inversus in the AudGen Database was conducted. Audiograms were analyzed for type of hearing loss (HL), severity, laterality, and progression. Medical charts were reviewed to identify factors that influence severity and progression of hearing loss.

RESULTS

56 patients met inclusion criteria and 42 patients had HL. 66.6% had bilateral and 33.3% had unilateral loss (70 total ears with HL). Conductive hearing loss (CHL) was the most common type of HL, though 30% of children had some sensorineural component to their hearing loss. 92.9% of children with HL received at least one diagnosis of otitis media, but HL did not improve in the majority (77.8%) of ears in our study regardless of ear tube placement.

CONCLUSIONS

Slight to mild CHL and all types of otitis media are prevalent among patients with PCD, and some of these children have sensorineural hearing loss (SNHL). All patients diagnosed with situs inversus at birth should be evaluated by an otolaryngologist.

Congenital Heart Defects and Ciliopathies Associated With Renal Phenotypes

Congenital heart disease (CHD) is one of the most common birth defects, and recent studies indicate cilia-related mutations play a central role in the genetic etiology of CHD. As cilia are also known to have important roles in kidney development and disease, it is not surprising that renal anomalies were found to be enriched among CHD mutant mice recovered in a large-scale mouse forward genetic screen. Indeed 42% of mutations identified to cause both CHD and renal anomalies were cilia-related. Many of these cilia mutations comprise cilia transition zone or inversin compartment components, consistent with the known role of these cilia proteins in a wide variety of ciliopathies. The high prevalence of CHD with congenital anomalies of the kidney and urinary tract (CAKUT) observed in mice was also corroborated with clinical studies that showed 20-30% of CHD patients have renal anomalies. Together these findings suggest CHD patients may benefit from early screening for renal anomalies to allow early diagnosis and intervention to improve outcome for this vulnerable patient population.

A pediatric disease to keep in mind: diagnostic tools and management of bronchiectasis in pediatric age

Bronchiectasis in pediatric age is a heterogeneous disease associated with significant morbidity.The most common medical conditions leading to bronchial damage are previous pneumonia and recurrent lower airway infections followed by underlying diseases such as immune-deficiencies, congenital airway defects, recurrent aspirations and mucociliary clearance disorders.The most frequent symptom is chronic wet cough. The introduction of high-resolution computed tomography (HRCT) has improved the time of diagnosis allowing earlier treatment.However, the term "bronchiectasis" in pediatric age should be used with caution, since some lesions highlighted with HRCT may improve or regress. The use of chest magnetic resonance imaging (MRI) as a radiation-free technique for the assessment and follow-up of lung abnormalities in non-Cystic Fibrosis chronic lung disease is promising.Non-Cystic Fibrosis Bronchiectasis management needs a multi-disciplinary team. Antibiotics and airway clearance techniques (ACT) represent the pillars of treatment even though guidelines in children are lacking. The Azithromycin thanks to its antinflammatory and direct antimicrobial effect could be a new strategy to prevent exacerbations.

Lessons From Unilateral Loss of Cilia: Early Nasal Nitric Oxide Gas Mixing and the Role of Sinus Patency in Determining Nasal Nitric Oxide

Nasal nitric oxide (nNO) measurement is a diagnostic test for primary ciliary dyskinesia (PCD). Here, we have shown the development of unilateral PCD-like symptoms associated with low nNO. A 60-year-old man had been previously healthy but developed unilateral, severe pansinusitis. He required surgical drainage of all left sinuses, and biopsies showed loss of the ciliated epithelium. At 4 weeks, he had unilateral (left-sided), profuse, clear rhinorrhea characteristic of PCD, and his surgical ostia were all patent endoscopically. His left-sided nNO was less than the right side by 37 ± 1.2 nL/min; this difference decreased to 18 ± 0.87 nL/min at 5 weeks and was gone by 6 weeks when his symptoms resolved. Measurements of 2- and 10-second measurements, in addition to standard nNO measurements, identified this discordance. We conclude that nNO reflects, in part, the production of NO by the ciliated epithelium, not just in the absence or occlusion of sinuses. Early (nasal/sinus volume) measures may be better for diagnosing PCD in than standard, steady-state assays in certain populations.

Chemoattractants and cytokines in primary ciliary dyskinesia and cystic fibrosis: key players in chronic respiratory diseases

Patients with primary ciliary dyskinesia (PCD) and cystic fibrosis (CF), two inherited disorders, suffer from recurrent airway infections characterized by persistent bacterial colonization and uncontrollable inflammation. Although present in high counts, neutrophils fail to clear infection in the airways. High levels of C-X-C motif chemokine ligand 8/interleukin-8 (CXCL8/IL-8), the most potent chemokine to attract neutrophils to sites of infection, are detected in the sputum of both patient groups and might cause the high neutrophil influx in the airways. Furthermore, in CF, airway neutrophils are highly activated because of the genetic defect and the high levels of proinflammatory chemoattractants and cytokines (e.g., CXCL8/IL-8, tumor necrosis factor-α and IL-17). The overactive state of neutrophils leads to lung damage and fuels the vicious circle of infection, excessive inflammation and tissue damage. The inflammatory process in CF airways is well characterized, whereas the lung pathology in PCD is far less studied. The knowledge of CF lung pathology could be useful to guide molecular investigations of the inflammatory processes in PCD lungs. Current available therapies can not completely remedy the chronic airway infections in these diseases. This review gives an overview of the role that chemoattractants and cytokines play in these neutrophil-dominated lung pathologies. Finally, the most frequently applied treatments in CF and PCD and new experimental therapies to reduce neutrophil-dominated airway inflammation are described.

Clinical care for primary ciliary dyskinesia: current challenges and future directions

Primary ciliary dyskinesia (PCD) is a rare genetic disease that affects the motility of cilia, leading to impaired mucociliary clearance. It is estimated that the vast majority of patients with PCD have not been diagnosed as such, providing a major obstacle to delivering appropriate care. Challenges in diagnosing PCD include lack of disease-specific symptoms and absence of a single, "gold standard", diagnostic test. Management of patients is currently not based on high-level evidence because research findings are mostly derived from small observational studies with limited follow-up period. In this review, we provide a critical overview of the available literature on clinical care for PCD patients, including recent advances. We identify barriers to PCD research and make suggestions for overcoming challenges.

Primary ciliary dyskinesia: mechanisms and management

Primary ciliary dyskinesia is a genetically heterogeneous disorder of motile cilia that is predominantly inherited in an autosomal-recessive fashion. It is associated with abnormal ciliary structure and/or function leading to chronic upper and lower respiratory tract infections, male infertility, and situs inversus. The estimated prevalence of primary ciliary dyskinesia is approximately one in 10,000-40,000 live births. Diagnosis depends on clinical presentation, nasal nitric oxide, high-speed video-microscopy analysis, transmission electron microscopy, genetic testing, and immunofluorescence. Here, we review its clinical features, diagnostic methods, molecular basis, and available therapies.

Diagnosis and management of children with primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a rare, genetic disorder of the motile cilia characterised by chronic lung disease, nasal and sinus disease, chronic ear infections with glue ear leading to possible hearing impairment, and subfertility. Half of patients have organ laterality defects. Despite symptoms being present from birth, PCD remains underdiagnosed. Early diagnosis and symptom management may reduce morbidity, improve quality of life and ensure children are adequately supported to meet their full potential. This article seeks to raise awareness of PCD in children's nurses who are well placed to identify children for referral to the national PCD diagnostic service. It examines the clinical characteristics of the disease along with the complexities and limitations of diagnostic testing. In addition, it explores the management of children with PCD within the national PCD management service for children.

Movement

Primary ciliary dyskinesia is an inherited disease characterized by impaired ciliary function leading to diverse clinical manifestations, including chronic sinopulmonary disease, persistent middle ear effusions, laterality defects, and infertility. Our understanding of the complex genetics and functional phenotypes of primary ciliary dyskinesia has rapidly grown, and over 35 disease-associated genes have been identified, which segregate into genes that encode axonemal motor proteins, regulatory proteins within the cilium, and cytoplasmic proteins involved in ciliary assembly. These findings have yielded unexpected insights into the clinical heterogeneity of disease and are beginning to revolutionize diagnostic testing for primary ciliary dyskinesia.

An effective combination of whole-exome sequencing and runs of homozygosity for the diagnosis of primary ciliary dyskinesia in consanguineous families

Primary ciliary dyskinesia (PCD) is clinically characterized by neonatal respiratory distress, chronic sinusitis, bronchiectasis and infertility, and situs inversus in 50% of the patients. PCD is a result of mutations in genes encoding proteins involved in ciliary function, and is primarily inherited in an autosomal recessive fashion. Diagnosis of PCD is often a challenging task due to its high clinical and genetic heterogeneities. In the present study, we attempted to use whole-exome sequencing (WES) combined with runs of homozygosity (ROH) approaches to identify the genetic defects in four Chinese consanguineous families with clinical PCD. We successfully identified three recently acknowledged PCD genes: DYX1C1, CCNO and ARMC4, and one well-characterized PCD gene, DNAI1. Our study provides compelling evidence that WES in combination with ROH analysis is an efficient diagnostic tool for identifying genetic causes of PCD in consanguineous families. Furthermore, our work expands the genetic mutation spectrum in PCD, and provides the additional tools to better serve the counseling of the families with PCD.

The Saudi Thoracic Society guidelines for diagnosis and management of noncystic fibrosis bronchiectasis

This is the first guideline developed by the Saudi Thoracic Society for the diagnosis and management of noncystic fibrosis bronchiectasis. Local experts including pulmonologists, infectious disease specialists, thoracic surgeons, respiratory therapists, and others from adult and pediatric departments provided the best practice evidence recommendations based on the available international and local literature. The main objective of this guideline is to utilize the current published evidence to develop recommendations about management of bronchiectasis suitable to our local health-care system and available resources. We aim to provide clinicians with tools to standardize the diagnosis and management of bronchiectasis. This guideline targets primary care physicians, family medicine practitioners, practicing internists and respiratory physicians, and all other health-care providers involved in the care of the patients with bronchiectasis.

Primary Ciliary Dyskinesia: An Update on Clinical Aspects, Genetics, Diagnosis, and Future Treatment Strategies

Primary ciliary dyskinesia (PCD) is an orphan disease (MIM 244400), autosomal recessive inherited, characterized by motile ciliary dysfunction. The estimated prevalence of PCD is 1:10,000 to 1:20,000 live-born children, but true prevalence could be even higher. PCD is characterized by chronic upper and lower respiratory tract disease, infertility/ectopic pregnancy, and situs anomalies, that occur in ≈50% of PCD patients (Kartagener syndrome), and these may be associated with congenital heart abnormalities. Most patients report a daily year-round wet cough or nose congestion starting in the first year of life. Daily wet cough, associated with recurrent infections exacerbations, results in the development of chronic suppurative lung disease, with localized-to-diffuse bronchiectasis. No diagnostic test is perfect for confirming PCD. Diagnosis can be challenging and relies on a combination of clinical data, nasal nitric oxide levels plus cilia ultrastructure and function analysis. Adjunctive tests include genetic analysis and repeated tests in ciliary culture specimens. There are currently 33 known genes associated with PCD and correlations between genotype and ultrastructural defects have been increasingly demonstrated. Comprehensive genetic testing may hopefully screen young infants before symptoms occur, thus improving survival. Recent surprising advances in PCD genetic designed a novel approach called "gene editing" to restore gene function and normalize ciliary motility, opening up new avenues for treating PCD. Currently, there are no data from randomized clinical trials to support any specific treatment, thus, management strategies are usually extrapolated from cystic fibrosis. The goal of treatment is to prevent exacerbations, slowing the progression of lung disease. The therapeutic mainstay includes airway clearance maneuvers mainly with nebulized hypertonic saline and chest physiotherapy, and prompt and aggressive administration of antibiotics. Standardized care at specialized centers using a multidisciplinary approach that imposes surveillance of lung function and of airway biofilm composition likely improves patients' outcome. Pediatricians, neonatologists, pulmonologists, and ENT surgeons should maintain high awareness of PCD and refer patients to the specialized center before sustained irreversible lung damage develops. The recent creation of a network of PCD clinical centers, focusing on improving diagnosis and treatment, will hopefully help to improve care and knowledge of PCD patients.

Primary ciliary dyskinesia presenting with spontaneous pneumothorax: Case report and review of the literature

BACKGROUND

Primary ciliary dyskinesia (PCD) is an autosomal recessive heterogeneous group of conditions with variable clinical findings.

CASE PRESENTATION

A 36-year-old nonsmoking Chinese man present to the emergency department of our hospital with acute-onset breathlessness and sudden-onset left-sided chest pain. The patient had 6 years primary infertility and suffered from recurrent episodes of respiratory tract infections since childhood. Chest X-ray was performed, which showed a left-sided pneumothorax with lung collapse. His conditions improved in clinical symptoms after 3 days of closed thoracic drainage. Radiographic findings after lung recruitment revealed bronchiectasis and bronchiolitis but no situs inversus. Paranasal sinus computed tomography (CT) showed maxillary sinusitis and ethmoid sinusitis. Pulmonary function tests demonstrated severe obstructive ventilation functional impairment. Bronchial mucosal cilia showed the absence of both outer and inner dynein arms of the microtubules (ODA and IDA). A culture of bronchoalveolar lavage fluid was positive for Pseudomonas aeruginosa. His clinical symptoms and CT images showed improvement after 1 month of treatment. A literature review revealed that few patients are diagnosed with PCD complicated with spontaneous pneumothorax. Within one year of follow-up, the patient showed good responses to local ICS+ LA beta₂ agonist combined with oral carbocistein.

CONCLUSIONS

Pneumothorax might be one of the complications of the PCD. Combination therapy including ICS+ LA beta₂ agonist and carbocistein could be a potential therapy to reduce the frequency of acute exacerbations and delay progression of PCD.

MPEG1/perforin-2 mutations in human pulmonary nontuberculous mycobacterial infections

Perforin-2 is a highly conserved pore-forming protein encoded by macrophage expressed gene 1 (MPEG1). A number of studies have shown that Perforin-2-deficient mice are unable to survive following a bacterial challenge that is nonlethal in WT mice. There is also recent evidence that Mpeg1+/- heterozygous mice display an intermediate killing ability compared with Mpeg1 WT and Mpeg1-/- mice. Despite these in vivo findings, to date, no perforin-2 deficiencies have been associated with human disease. Here, we report four patients with persistent nontuberculous mycobacterial infection who had heterozygous MPEG1 mutations. In vitro, neutrophils, macrophages, and B cells from these patients were unable to kill Mycobacterium avium as efficiently as normal controls. CRISPR mutagenesis validated the deleterious antibacterial activity of these mutations. These data suggest that perforin-2 haploinsufficiency may contribute to human susceptibility to infections with intracellular bacteria.

[Bronchiectasis]

The paper presents information on possible approaches to the classification, pathogenesis, and determination of the etiological causes of bronchiectasis. It discusses a group of bronchiectasis-associated diseases. It gives a detailed diagnostic algorithm aimed to establish the etiology of bronchiectasis and the markers of the efficiency of different treatment options. Much attention is paid to genetically predetermined bronchiectasis. Universal approaches to treating patients with bronchiectasis as a whole, as well as treatments for certain entities of bronchiectasis are discussed.

Respiratory manifestations in 38 patients with Alström syndrome

OBJECTIVES

Alström syndrome (AS) is a rare, multi-system condition characterized by retinal degeneration, sensorineural hearing loss, obesity, insulin-resistant diabetes, hypertriglyceridemia, cardiomyopathy, hepatorenal disease, and recurrent respiratory infections. It belongs to a group of genetic disorders known as primary ciliopathies, which includes autosomal dominant and recessive polycystic kidney diseases, as well as Joubert and Bardet-Biedl syndromes. Prior studies have suggested phenotypic overlap between primary ciliopathies affecting the non-motile, sensory cilia, and primary ciliary dyskinesia (PCD), a motile ciliopathy characterized by respiratory tract disease.

METHODS

We describe the burden of oto-sino-pulmonary disease in 38 individuals with AS and examines the degree of clinical overlap between PCD and AS. Evaluation at the NIH Clinical Center included clinical examination, chest imaging, and clinical history surveys, as well as measurement of nasal nitric oxide (nNO) in nine patients.

RESULTS

Recurrent otitis media was ubiquitous in the AS cohort (92%) with 50% requiring pressure equalization tube placement. A history of bronchitis/pneumonia and sinusitis was reported in 61% and 50% of individuals, respectively. PCD-characterizing symptoms (laterality defects, unexplained neonatal respiratory distress, year-round nasal congestion, and wet cough) were far less prevalent in the AS cohort compared to PCD, and the average nNO production in the AS cohort was 232 ± 57.1 nl/min compared to a cut-off of <77 nl/min for PCD.

CONCLUSIONS

These data suggest that the oto-sino-respiratory complications in AS are prominent enough to warrant increased clinical attention, but significantly impaired respiratory cilia function as seen in PCD is unlikely in AS. (www.clinicaltrials.gov, trial NCT00068224) Pediatr Pulmonol. 2017;52:487-493. © 2016 Wiley Periodicals, Inc.

The patient's experience of primary ciliary dyskinesia: a systematic review

Background

Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterised by progressive sinopulmonary disease, with symptoms starting soon after birth. The aim of this study is to critically review, analyse, and synthesise the literature in order to understand the experiences of patients with primary ciliary dyskinesia (PCD) and the impact on health-related quality of life.

Method

MEDLINE, EBSCO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO and EMBASE were searched according to the inclusion criteria. A qualitative analysis of 14 studies was conducted.

Results

Fourteen studies were included in the review, five with qualitative methodologies. Studies originated from the UK, USA, Italy, Denmark and Belgium, one study included a survey distributed internationally. Significant relationships were found between age and worsening of respiratory symptoms, physical, and mental domains of health-related quality of life, with a greater decline compared with reference populations. Variations between the UK and Italy were found for health-related quality of life and its correlation with time since diagnosis. PCD was found to have a physical impact in all age groups: patients found it difficult to keep up with others, and found energy levels were easily depleted compared to family or peers. In terms of social impact, symptoms lead to embarrassment and a sense of isolation, with patients concealing symptoms and/or their diagnosis. In turn, isolation was also linked with the lack of public and medical knowledge. In relation to emotional impact, anxiety was reported in a number of qualitative studies; patients were anxious about getting sick or when thinking about their future health. The burden of treatment and factors influencing adherence were also discussed in depth.

Conclusion

Health-related quality of life decreases with age in patients with PCD. For all age groups, PCD was found to greatly impact physical, emotional, social functioning, and treatment burden. More research is needed on the psychosocial impact of the illness, disease burden and its effect on quality of life.

Extended Endoscopic and Open Sinus Surgery for Refractory Chronic Rhinosinusitis

This review discusses extended endoscopic and open sinus surgery for refractory chronic rhinosinusitis. Extended maxillary sinus surgery including endoscopic maxillary mega-antrostomy, endoscopic modified medial maxillectomy, and inferior meatal antrostomy are described. Total/complete ethmoidectomy with mucosal stripping (nasalization) is discussed. Extended endoscopic sphenoid sinus procedures as well as their indications and potential risks are reviewed. Extended endoscopic frontal sinus procedures, such the modified Lothrop procedure, are described. Extended open sinus surgical procedures, such as the Caldwell-Luc approach, frontal sinus trephine procedure, external frontoethmoidectomy, frontal sinus osteoplastic flap with or without obliteration, and cranialization, are discussed.

Assessment of ciliary phenotype in primary ciliary dyskinesia by micro-optical coherence tomography

Ciliary motion defects cause defective mucociliary transport (MCT) in primary ciliary dyskinesia (PCD). Current diagnostic tests do not assess how MCT is affected by perturbation of ciliary motion. In this study, we sought to use micro-optical coherence tomography (μOCT) to delineate the mechanistic basis of cilia motion defects of PCD genes by functional categorization of cilia motion. Tracheae from three PCD mouse models were analyzed using μOCT to characterize ciliary motion and measure MCT. We developed multiple measures of ciliary activity, integrated these measures, and quantified dyskinesia by the angular range of the cilia effective stroke (ARC). Ccdc39^-/- mice, with a known severe PCD mutation of ciliary axonemal organization, had absent motile ciliary regions, resulting in abrogated MCT. In contrast, Dnah5^-/- mice, with a missense mutation of the outer dynein arms, had reduced ciliary beat frequency (CBF) but preserved motile area and ciliary stroke, maintaining some MCT. Wdr69^-/- PCD mice exhibited normal motile area and CBF and partially delayed MCT due to abnormalities of ciliary ARC. Visualization of ciliary motion using μOCT provides quantitative assessment of ciliary motion and MCT. Comprehensive ciliary motion investigation in situ classifies ciliary motion defects and quantifies their contribution to delayed mucociliary clearance.

Bacterial infections in patients with primary ciliary dyskinesia: Comparison with cystic fibrosis

Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder associated with severely impaired mucociliary clearance caused by defects in ciliary structure and function. Although recurrent bacterial infection of the respiratory tract is one of the major clinical features of this disease, PCD airway microbiology is understudied. Despite the differences in pathophysiology, assumptions about respiratory tract infections in patients with PCD are often extrapolated from cystic fibrosis (CF) airway microbiology. This review aims to summarize the current understanding of bacterial infections in patients with PCD, including infections with Pseudomonas aeruginosa, Staphylococcus aureus, and Moraxella catarrhalis, as it relates to bacterial infections in patients with CF. Further, we will discuss current and potential future treatment strategies aimed at improving the care of patients with PCD suffering from recurring bacterial infections.

Validation of a health-related quality of life instrument for primary ciliary dyskinesia (QOL-PCD)

Background

Quality of life (QOL)-primary ciliary dyskinesia (PCD) is the first disease-specific, health-related QOL instrument for PCD. Psychometric validation of QOL-PCD assesses the performance of this measure in adults, including its reliability, validity and responsiveness to change.

Methods

Seventy-two adults (mean (range) age: 33 years (18–79 years); mean (range) FEV₁% predicted: 68 (26–115)) with PCD completed the 49-item QOL-PCD and generic QOL measures: Short-Form 36 Health Survey, Sino-Nasal Outcome Test 20 (SNOT-20) and St George Respiratory Questionnaire (SGRQ)-C. Thirty-five participants repeated QOL-PCD 10–14 days later to measure stability or reproducibility of the measure.

Results

Multitrait analysis was used to evaluate how the items loaded on 10 hypothesised scales: physical, emotional, role and social functioning, treatment burden, vitality, health perceptions, upper respiratory symptoms, lower respiratory symptoms and ears and hearing symptoms. This analysis of item-to-total correlations led to 9 items being dropped; the validated measure now comprises 40 items. Each scale had excellent internal consistency (Cronbach's α: 0.74 to 0.94). Two-week test–retest demonstrated stability for all scales (intraclass coefficients 0.73 to 0.96). Significant correlations were obtained between QOL-PCD scores and age and FEV₁. Strong relationships were also found between QOL-PCD scales and similar constructs on generic questionnaires, for example, lower respiratory symptoms and SGRQ-C (r=0.72, p<0.001), while weak correlations were found between measures of different constructs.

Conclusions

QOL-PCD has demonstrated good internal consistency, test–retest reliability, convergent and divergent validity. QOL-PCD offers a promising tool for evaluating new therapies and for measuring symptoms, functioning and QOL during routine care.

Laparoscopy-assisted distal gastrectomy in a case of gastric cancer with situs inversus totalis: a case report

Situs inversus totalis (SIT) is a rare congenital condition in which abdominal and thoracic organs are transposed from normal positions. Laparoscopy-assisted distal gastrectomy for situs inversus totalis is technically difficult and has rarely been reported. Here, we report the case of man in his 40s with situs inversus totalis and a preoperative diagnosis of stage IA gastric cancer (cT1b, cN0, cM0). We successfully performed laparoscopy-assisted distal gastrectomy with D1+ lymph node dissection and Billroth I reconstruction. To ensure a safe procedure, we evaluated the vessels preoperatively with 3-D CT angiography. Furthermore, we performed the surgery by reversing our surgical positions, using a two-monitor method, and then reconstructing under direct vision through the incision. The surgery was performed with minimal blood loss, and no severe postoperative complications were observed. Histopathological examination revealed poorly to moderately differentiated stage IA (pT1b, pN0, pM0) adenocarcinoma. No recurrence has been observed as of 2 years postoperatively.

Alternative inert gas washout outcomes in patients with primary ciliary dyskinesia

The lung clearance index (LCI) derived from a nitrogen multiple breath washout test (N2-MBW) is a promising tool to assess small airways disease in primary ciliary dyskinesia, but it is difficult to apply in routine clinical settings because of its long measuring time. In this study, we aimed to assess alternative indices derived from shorter washout protocols.

49 patients with primary ciliary dyskinesia (mean age 14.7±6.6 years) and 37 controls (mean age 14.3±1.4 years) performed N2-MBW and double-tracer gas (DTG) single-breath washout tests. Global (LCI and moment ratio (M2/M0)), conductive (Scond) and acinar ventilation inhomogeneity (DTG Slope III (SIII-DTG)) were determined for each individual. The main outcomes were 1) the ability to detect abnormal lung function from washout indices (>1.64 z-scores) and 2) measurement duration.

The prevalence of abnormal values for LCI2.5% was 37 out of 47 (79%), for LCI5% was 34 out of 47 (72%), for M2/M0 was 34 out of 47 (72%), for Scond was 36 out of 46 (78%) and for SIII-DTG was 12 out of 35 (34%). Mean±sd duration of measurement was 19.8±11.2 min for LCI2.5%, 10.8±4.6 min for LCI5% and 8.6±2.3 min for Scond.

Compared to standard LCI2.5%, ventilation inhomogeneity was detected by LCI5%, moment ratio and Scond with comparable sensitivity while measurement duration was significantly shorter. Longitudinal studies will show which outcome is most suitable and practical in terms of sensitivity, duration and variability within the course of primary ciliary dyskinesia lung disease.

Diagnosis of primary ciliary dyskinesia: potential options for resource-limited countries

Primary ciliary dyskinesia is a genetic disease of ciliary function leading to chronic upper and lower respiratory tract symptoms. The diagnosis is frequently overlooked because the symptoms are nonspecific and the knowledge about the disease in the primary care setting is poor. Additionally, none of the available tests is accurate enough to be used in isolation. These tests are expensive, and need sophisticated equipment and expertise to analyse and interpret results; diagnosis is therefore only available at highly specialised centres. The diagnosis is particularly challenging in countries with limited resources due to the lack of such costly equipment and expertise.

In this review, we discuss the importance of early and accurate diagnosis especially for countries where the disease is clinically prevalent but diagnostic tests are lacking. We review the diagnostic tests available in specialised centres (nasal nitric oxide, high-speed video microscopy, transmission electron microscopy, immunofluorescence and genetics). We then consider modifications that might be considered in less well-resourced countries whilst maintaining acceptable accuracy.

The international primary ciliary dyskinesia cohort (iPCD Cohort): methods and first results

Data on primary ciliary dyskinesia (PCD) epidemiology is scarce and published studies are characterised by low numbers. In the framework of the European Union project BESTCILIA we aimed to combine all available datasets in a retrospective international PCD cohort (iPCD Cohort).

We identified eligible datasets by performing a systematic review of published studies containing clinical information on PCD, and by contacting members of past and current European Respiratory Society Task Forces on PCD. We compared the contents of the datasets, clarified definitions and pooled them in a standardised format.

As of April 2016 the iPCD Cohort includes data on 3013 patients from 18 countries. It includes data on diagnostic evaluations, symptoms, lung function, growth and treatments. Longitudinal data are currently available for 542 patients. The extent of clinical details per patient varies between centres. More than 50% of patients have a definite PCD diagnosis based on recent guidelines. Children aged 10–19 years are the largest age group, followed by younger children (≤9 years) and young adults (20–29 years).

This is the largest observational PCD dataset available to date. It will allow us to answer pertinent questions on clinical phenotype, disease severity, prognosis and effect of treatments, and to investigate genotype–phenotype correlations.

The iPCD Cohort offers a unique opportunity to study PCD in an international retrospective cohort of >3000 patientshttp://ow.ly/rn0m304Jgsu

Chronic Suppurative Lung Disease in Children: Definition and Spectrum of Disease

The most common clinical suppurative lung conditions in children are empyema, lung abscess, and bronchiectasis, and to a less often necrotizing pneumonia. Until recently, bronchiectasis was the most common form of persistent suppurative lung disease in children. Protracted bacterial bronchitis is a newly described chronic suppurative condition in children, which is less persistent but more common than bronchiectasis (1). In addition, the term "chronic suppurative lung disease" has been used recently to describe the clinical features of bronchiectasis when the radiographic features needed to make a diagnosis of bronchiectasis are absent. Webster's New College Dictionary defines suppuration as the process of forming and/or discharging pus. Pus is a body fluid resulting from intense inflammation in response to infection that leads to neutrophil influx and apoptosis, microbial clearance, and often necrosis of nearby tissue. Pus is primarily composed of white blood cell debris.

Clinical and genetic analysis of a family with Kartagener syndrome caused by novel DNAH5 mutations

PURPOSE

Kartagener syndrome (KS), also known as visceral inversion-nasosinusitis-bronchiectasis syndrome, or familial bronchiectasis, is an autosomal recessive inherited disease. In this study, through two cases of KS, we aimed to assess the clinical and genetic characteristics of KS caused by DNAH5 mutations.

METHODS

The two cases of KS from the same family underwent extensive clinical assessments, with next-generation DNA sequencing and bioinformatics analysis to identify pathogenic genes. In addition, Sanger sequencing was used to verify the pedigrees.

RESULTS

The present study employed a directional capture strategy for hereditary disease screening, which correctly identified the virulence sites in the pedigree, and facilitated the differential diagnosis among multiple genes. Two novel mutations were detected in DNAH5: c.7778C>T (missense mutation) and c.13729G>A (nonsense mutation). They were not found in dbSNP, 1000 Genomes, and ExAC.

CONCLUSIONS

These findings demonstrated that new DNAH5 mutations could be used for molecular diagnosis of KS, providing families with genetic counseling and prenatal diagnosis.

Proceedings of the COST action BM1407 inaugural conference BEAT-PCD: translational research in primary ciliary dyskinesia - bench, bedside, and population perspectives

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 Framework Programme Horizon 2020 funded COST Action (BM1407). The Inaugural Conference of BEAT-PCD was held in December 2015 in Southampton, UK. The conference attracted ninety-six scientists, clinicians, allied health professionals, industrial partners and patient representatives from twenty countries. We aimed to identify the needs for PCD research and clinical care, particularly focussing on 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. This allowed us to develop plans for collaborative studies. In this report, we summarize the meeting, highlight developments, and discuss open questions thereby documenting ongoing developments in the field of PCD research.

A longitudinal evaluation of hearing and ventilation tube insertion in patients with primary ciliary dyskinesia

INTRODUCTION

Primary ciliary dyskinesia (PCD) is an autosomal recessive genetic disease, which primarily manifests with oto-sino-pulmonary symptoms. Otitis media with effusion (OME) is common from early childhood. The existing literature on OME management in PCD is conflicting. The goals of the present study were firstly to evaluate the long-term hearing in PCD patients and secondly to determine the influence of ventilation tube (VT) insertion on hearing and postoperative otorrhoea.

METHODS

A longitudinal retrospective study extracting the hearing level (pure tone average (0.5, 1, 2, 4 kHz, PTA)) and tympanometry from the medical records. Furthermore, the patient files were reviewed for VT insertion and postoperative otorrhoea. Postoperative otorrhoea was defined prolonged when it lasted for four weeks or longer.

RESULTS

Fifty-seven patients were identified in a 30-year period, age 2-72 years, and 278 audiometries were evaluated. The median number of audiometries per patient was 3 (range 1-29) and the median follow-up was 60 months (range 0-351 months). The mean PTA was 34 dB HL in patients below six years of age and improved significantly (p < 0.0001) with age. VT insertion improved hearing; however, 48% of patients with VT insertion experienced prolonged otorrhoea.

CONCLUSION

In this study of PCD patients the hearing improved as a function of age as well as following VT insertion. However, VT insertion was also associated with prolonged otorrhoea.

Diagnosis of Primary Ciliary Dyskinesia by a Targeted Next-Generation Sequencing Panel: Molecular and Clinical Findings in Italian Patients

Primary ciliary dyskinesia (PCD) is a rare genetic disorder that alters mucociliary clearance, with consequent chronic disease of upper and lower airways. Diagnosis of PCD is challenging, and genetic testing is hampered by the high heterogeneity of the disease, because autosomal recessive causative mutations were found in 34 different genes. In this study, we clinically and molecularly characterized a cohort of 51 Italian patients with clinical signs of PCD. A custom next-generation sequencing panel that enables the affordable and simultaneous screening of 24 PCD genes was developed for genetic analysis. After variant filtering and prioritization, the molecular diagnosis of PCD was achieved in 43% of the patients. Overall, 5 homozygous and 27 compound heterozygous mutations, 21 of which were never reported before, were identified in 11 PCD genes. The DNAH5 and DNAH11 genes were the most common cause of PCD in Italy, but some population specificities were identified. In addition, the number of unsolved cases and the identification of only a single mutation in six patients suggest further genetic heterogeneity and invoke the need of novel strategies to detect unconventional pathogenic DNA variants. Finally, despite the availability of mutation databases and in silico prediction tools helping the interpretation of variants in next-generation sequencing screenings, a comprehensive segregation analysis is required to establish the in trans inheritance and support the pathogenic role of mutations.

A novel method for investigating Burkholderia cenocepacia infections in patients with cystic fibrosis and other chronic diseases of the airways

BACKGROUND

Burkholderia cenocepacia is a Gram-negative, opportunistic pathogen that is a cause of morbidity and mortality in patients with cystic fibrosis (CF). Research efforts over the past few decades contributed to our understanding of these infections by identifying virulence factors. However, little is known about how this pathogen adapts to the harsh environment found inside the CF airways, which is characterized by a unique mucus containing high concentrations of inflammatory markers. The current study developed a novel model to further investigate this phenomenon.

RESULTS

Monolayers of human A549 lung carcinoma cells (HLCCs) were exposed to a mixture of artificial CF sputum medium (ASMDM) in tissue culture growth medium, and subsequently infected with B. cenocepacia K56-2 for 24 h. The data showed that this model supported B. cenocepacia growth. In addition, consistent with similar studies using current models such as CF airway tissue samples, HLCC viability was reduced by more than 70 % when grown in 60 % ASMDM and infected with B. cenocepacia compared to mock-infected controls and medium alone. Furthermore, the amount of B. cenocepacia cells associated with the HLCC monolayer was more than 10 times greater in 60 % ASMDM when compared to medium controls.

CONCLUSIONS

These findings suggest that HLCC monolayers in 60 % ASMDM serve as a valid alternative to study B. cenocepacia infections in patients with CF, and possibly other chronic diseases of the airways. Furthermore, the results obtained in this study suggest an important role for CF sputum in B. cenocepacia pathogenesis.

Collecting clinical data in primary ciliary dyskinesia- challenges and opportunities

Rationale: Primary ciliary dyskinesia (PCD) is under diagnosed and underestimated. Most clinical research has used some form of questionnaires to capture data but none has been critically evaluated particularly with respect to its end-user feasibility and utility.

Objective: To critically appraise a clinical data collection questionnaire for PCD used in a large national PCD consortium in order to apply conclusions in future PCD research.

Methods: We describe the development, validation and revision process of a clinical questionnaire for PCD and its evaluation during a national clinical PCD study with respect to data collection and analysis, initial completion rates and user feedback.

Results: 14 centers participating in the consortium successfully completed the revised version of the questionnaire for 173 patients with various completion rates for various items. While content and internal consistency analysis demonstrated validity, there were methodological deficiencies impacting completion rates and end-user utility. These deficiencies were addressed resulting in a more valid questionnaire.

Conclusions: Our experience may be useful for future clinical research in PCD. Based on the feedback collected on the questionnaire through analysis of completion rates, judgmental analysis of the content, and feedback from experts and end users, we suggest a practicable framework for development of similar tools for various future PCD research.

Clinical manifestations in primary ciliary dyskinesia: systematic review and meta-analysis

Few original studies have described the prevalence and severity of clinical symptoms of primary ciliary dyskinesia (PCD). This systematic review and meta-analysis aimed to identify all published studies on clinical manifestations of PCD patients, and to describe their prevalence and severity stratified by age and sex.We searched PubMed, Embase and Scopus for studies describing clinical symptoms of ≥10 patients with PCD. We performed meta-analyses and meta-regression to explain heterogeneity.We included 52 studies describing a total of 1970 patients (range 10-168 per study). We found a prevalence of 5% for congenital heart disease. For the rest of reported characteristics, we found considerable heterogeneity (I² range 68-93.8%) when calculating the weighted mean prevalence. Even after taking into account the explanatory factors, the largest part of the between-studies variance in symptom prevalence remained unexplained for all symptoms. Sensitivity analysis including only studies with test-proven diagnosis showed similar results in prevalence and heterogeneity.Large differences in study design, selection of study populations and definition of symptoms could explain the heterogeneity in symptom prevalence. To better characterise the disease, we need larger, multicentre, multidisciplinary, prospective studies that include all age groups, use uniform diagnostics and report on all symptoms.