Diagnosis, monitoring, and treatment of primary ciliary dyskinesia: PCD foundation consensus recommendations based on state of the art review

Inhaled DNAI1 mRNA therapy for treatment of primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder caused by mutations in one of at least 50 different genes that encode proteins involved in the biogenesis, structure, or function of motile cilia. Genetically inherited defects in motile cilia cause PCD, a debilitating respiratory disease for which there is no approved therapy. The dynein axonemal intermediate chain 1 (DNAI1) protein is a key structural element of the ciliary outer dynein arm (ODA) critical for normal ciliary activity and subsequent clearance of mucus from the conducting airways in humans. Loss-of-function mutations in DNAI1 account for up to 10% of all PCD cases, with functional abnormalities in patients presenting at or near birth and leading to a life-long course of disability, including progressive loss of lung function and bronchiectasis by adulthood. This underscores the significant unmet need for disease-modifying treatments that restore ciliary activity and mucociliary clearance in PCD patients. In this work, we demonstrate that lipid nanoparticle (LNP)-formulated human DNAI1 mRNA can be delivered as an aerosol to primary human bronchial epithelial cell models and to nonhuman primate (NHP) lungs. Additionally, we show that delivery of aerosolized LNP-DNAI1 mRNA to NHPs leads to detectable levels of newly translated human DNAI1 protein, at doses that overlap with exposures in an in vitro cell-based PCD model enabling rescue of ciliary function. Therefore, these data support further development of the inhaled DNAI1 mRNA therapy in clinical studies as a potential disease-modifying treatment for PCD.

Lung Function Recovery from Pulmonary Exacerbations Treated with Oral Antibiotics in Primary Ciliary Dyskinesia

Rationale: Patients with primary ciliary dyskinesia (PCD) experience acute pulmonary exacerbations (PExs). In patients with cystic fibrosis (CF), PExs that were treated with oral antibiotics (oPExs) were found to be related to short- and long-term lung function deficits; however, the impact of oPExs on lung function in patients with PCD has not yet been assessed. Objectives: We sought to assess the impact of oPExs on lung function recovery in PCD and determine the factors associated with poorer response. Methods: This was a retrospective study of pediatric patients with PCD who were followed from 2000 to 2022 at The Hospital for Sick Children (Toronto, Ontario, Canada). PExs were defined as an increase in baseline symptoms with a physician's decision to treat with systemic intravenous or oral antibiotics. Lung function recovery was defined as a forced expiratory volume in 1 second (FEV1) measurement ⩾90% of a stable baseline within 12 months before the PEx. Univariate and multivariate analyses were completed to identify risk factors for nonresponse. Results: A total of 337 PEx events in 85 patients were included in this analysis, of which 297 (88%) were treated with oral antibiotics. The mean follow up time for patients was 6.7 years (SD = 3.5), and the mean age of patients with an oPEx was 12.5 years (SD = 3.2). Patients with an oPEx had a significant drop from baseline in mean FEV1 values at the time of the PEx (85.1-69.5%), with absolute and relative changes of -10.4% and -12.9%, respectively. At follow up (3 mo post PEx) and up to 12 mo post PEx, the means for FEV1 were 79.6% and 84.1%, respectively. A total of 73.2% of the patients had lung function recovery at the follow up visit, which increased to 84.2% within 1 year postevent. We identified two risk factors for nonresponse: being a nonresponder on the last PEx and younger age at time of the oPEx. Conclusions: oPExs in patients with PCD show a similar pattern previously seen in patients with CF who showed a decrease in FEV1 during exacerbation and an improvement posttherapy. Most oPEx events recover to baseline FEV1 within the year postexacerbation, with younger age and being a nonresponder in the last PEx identified as risk factors for nonresponse.

Overlapping Clinical Phenotypes in Patients with Primary Ciliary Dyskinesia or Activated Phosphoinositide 3-Kinase Delta Syndrome

Primary ciliary dyskinesia and activated phosphoinositide 3-kinase delta syndrome type 1 present similarly, with recurrent respiratory infections and reduced nasal nitric oxide levels. When diagnostic confirmation of primary ciliary dyskinesia with genetic testing and/or ciliary electron microscopy is inconclusive, activated phosphoinositide 3-kinase delta syndrome type 1 and other inborn errors of immunity must be investigated.

Primary ciliary dyskinesia cases bronchoscopic sampling and TEM analysis: sampling & diagnosis in PCD

Primary ciliary dyskinesia (PCD) is a rare, genetically heterogeneous disorder characterized by impaired ciliary structure and function, leading to chronic respiratory symptoms and recurrent infections. Despite its clinical significance, PCD diagnosis remains challenging due to its variable presentation and the lack of a gold standard diagnostic test. Specific clinical criteria, including neonatal respiratory distress and laterality defects, aid in suspicion of PCD, but confirmatory diagnosis often requires a combination of tests. In this study, we aimed to assess the efficacy of bronchoscopic techniques in obtaining respiratory epithelial samples for transmission electron microscopy (TEM) analysis. We enrolled adults with bronchiectasis and suspected PCD who underwent fiberoptic bronchoscopy. Bronchial forceps and brush biopsies were obtained from specific bronchial segments under conscious sedation. Tissue samples were processed for TEM analysis to identify ultrastructural axonemal defects associated with PCD. Our study included 10 patients (3 females, 7 males) aged 19-38 years, with detailed demographics and clinical characteristics provided. Evaluation of tracheobronchial biopsy samples revealed higher histological scores for the presence of ciliated cells and transverse sections of cilia in pellets obtained from brush biopsies and fixative solutions of forceps biopsy compared to forceps biopsy tissue samples. Electron microscopic examination of ultra-thin sections demonstrated abundant ciliated cells and abnormal cilia structures, aiding in the diagnosis of PCD in pellets. PCD represents a significant etiology of bronchiectasis, emphasizing the need for accurate diagnosis and appropriate management strategies. Our findings highlight the importance of bronchoscopic techniques, including bronchial brushing alongside forceps biopsies, in enhancing diagnostic yield and guiding timely intervention to improve patient outcomes.

Primary Ciliary Dyskinesia: Aetiology, Diagnosis and Clinical Management

Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterized by abnormal function of motile cilia. The condition usually manifests in early life with neonatal distress, chronic sinopulmonary disease and organ laterality disorders. In adults, it is an underdiagnosed cause of bronchiectasis as well as subfertility. This review provides an overview of PCD for clinicians. We discuss its aetiology, its presentation, how it is diagnosed and its multidisciplinary clinical management.

An amino acid-resolution interactome for motile cilia identifies the structure and function of ciliopathy protein complexes

Motile cilia are ancient, evolutionarily conserved organelles whose dysfunction underlies motile ciliopathies, a broad class of human diseases. Motile cilia contain a myriad of different proteins that assemble into an array of distinct machines, and understanding the interactions and functional hierarchies among them presents an important challenge. Here, we defined the protein interactome of motile axonemes using cross-linking mass spectrometry in Tetrahymena thermophila. From over 19,000 cross-links, we identified over 4,700 unique amino acid interactions among over 1,100 distinct proteins, providing both macromolecular and atomic-scale insights into diverse ciliary machines, including the intraflagellar transport system, axonemal dynein arms, radial spokes, the 96-nm ruler, and microtubule inner proteins. Guided by this dataset, we used vertebrate multiciliated cells to reveal functional interactions among several poorly defined human ciliopathy proteins. This dataset provides a resource for studying the biology of an ancient organelle and the molecular etiology of human genetic disease.

Beyond the present: current and future perspectives on the role of infections in pediatric PCD

Introduction

Primary Ciliary Dyskinesia (PCD) is a rare genetic disorder affecting motile cilia, leading to impaired mucociliary clearance and increased susceptibility to respiratory infections. These infections contribute to long-term complications such as bronchiectasis and lung function decline.

Objectives

This review explores both the acute and long-term impact of respiratory infections in children with PCD, while highlighting the multiple contributors to infection susceptibility. The review also evaluates emerging personalized approaches such as gene and mRNA therapy that hold promise for restoring ciliary function and reducing the burden of acute infections in pediatric PCD.

Key findings and conclusions

Acute respiratory infections have a significant impact on morbidity in pediatric PCD, driving progressive airway remodeling. While current treatment strategies focus on managing infections directly, emerging therapies targeting inflammation and genetic causes hold promise for reducing infection burden and improving long-term outcomes. Future advances in personalized medicine could further enhance therapeutic approaches in this population.

Understanding primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a rare, inherited disease characterized by impaired motile ciliary function leading to chronic sinopulmonary disease, persistent middle ear effusions, laterality defects, and subfertility. Over fifty PCD-associated genes have also been identified, which have provided new insights into the processes involved into ciliary assembly, structure, and function. Historically, the diagnosis of PCD was based on the presence of ultrastructural defects in the ciliary axoneme but with identification of a growing number of disease-associated genes, genetic testing has become a first-line diagnostic tool. Other approaches have also evolved, that have improved our diagnostic capabilities. Treatments for PCD have lagged, and though our growing understanding of the genetic and pathophysiological bases of the disease of PCD may yield to better therapeutic strategies.

Primary Ciliary Dyskinesia Complicated by Stroke in an Elderly Male: A Case Report

Kartagener syndrome (KS) is an uncommon hereditary disorder, featuring situs inversus, chronic sinusitis, and bronchiectasis. Our case report presents a 60-year-old Asian male with KS who was incidentally diagnosed with KS upon presenting with an ischemic cerebrovascular accident (CVA). The patient had a longstanding history of poorly controlled type 2 diabetes mellitus and hypertension, presenting with acute right-sided weakness and speech impairment. His history of recurrent respiratory infections and infertility, combined with family findings of dextrocardia and male infertility, suggested KS. On physical examination, the patient exhibited signs of dextrocardia. Imaging confirmed situs inversus and dextrocardia, while neurological evaluation revealed an embolic stroke in the left middle cerebral artery territory. Certain cardiovascular anomalies in KS may affect stroke risk; however, their co-occurrence in the patient appears to be coincidental, given the patient's baseline risk for stroke. A high-resolution chest CT demonstrated bronchiectasis and carotid Doppler ultrasound identified atherosclerotic plaques, likely contributing to the stroke. This case highlights the need for heightened awareness of neurological events, such as stroke, in patients with KS. Cardiovascular risk factors, compounded by the complexity of the syndrome, require prompt evaluation and multidisciplinary care to prevent severe complications.

The Impact of Age of Diagnosis in Children with Primary Ciliary Dyskinesia

Rationale: The typical symptoms of primary ciliary dyskinesia (PCD) manifest after birth and in early infancy, but diagnosis is often not confirmed during infancy. There is currently a lack of evidence in PCD regarding the impact of the age of the patient at the time of diagnosis on clinical outcomes. Objective: To determine whether early diagnosis of PCD is related to improved long-term outcomes. Methods: This was a retrospective study of patients diagnosed with PCD between 2000 and 2022. We divided our cohort into three groups according to the age at diagnosis: (1) early diagnosis (age <1 year), typical diagnosis (age 1-7 years), and late diagnosis (age 8-14 years). We compared various clinical long-term outcomes between the groups. Results: During the study period, 110 patients were included in the analysis, with 41 patients in the early diagnosis group, 35 in the typical diagnosis group, and 34 in the late diagnosis group. Unexplained neonatal respiratory distress and organ laterality defect were more common in the early diagnosis group, with respective rates in the early, typical, and late diagnosis groups of 80%, 53%, and 61% for neonatal respiratory distress (P = 0.045) and 64%, 50%, and 18% for laterality defect (P < 0.001). At the end of the first decade of life, patients in the early and typical-age diagnosis groups had better forced expiratory volume in 1 second compared with the late diagnosis group (93.5% and 93.1% vs. 80.2%; P = 0.002), but there was no significant change in the annual rate of decline between the groups when diagnosis had been confirmed. Patients diagnosed late had significantly higher rates of pulmonary exacerbations than those diagnosed at a typical age (1.95 vs. 0.75 per year; P < 0.01) Conclusions: Late diagnosis (age ≥8 years) was associated with lower forced expiratory volume in 1 second throughout childhood, although, once diagnosed, the annual rate of decline was not different. These findings demonstrate the negative effect of delayed diagnosis in pediatric PCD.

Human asthenozoospermia: Update on genetic causes, patient management, and clinical strategies

BACKGROUND

In mammals, sperm fertilization potential relies on efficient progression within the female genital tract to reach and fertilize the oocyte. This fundamental property is supported by the flagellum, an evolutionarily conserved organelle, which contains dynein motor proteins that provide the mechanical force for sperm propulsion and motility. Primary motility of the sperm cells is acquired during their transit through the epididymis and hyperactivated motility is acquired throughout the journey in the female genital tract by a process called capacitation. These activation processes rely on the micro-environment of the genital tracts. In particular, during capacitation, a panoply of ion transporters located at the surface of the sperm cells mediate complex ion exchanges, which induce an increase in plasma membrane fluidity, the alkalinization of the cytoplasm and protein phosphorylation cascades that are compulsory for sperm hyperactivation and fertilization potential. As a consequence, both structural and functional defects of the sperm flagellum can affect sperm motility, resulting in asthenozoospermia, which constitutes the most predominant pathological condition associated with human male infertility.

OBJECTIVES

Herein, we have performed a literature review to provide a comprehensive description of the recent advances in the genetics of human asthenozoospermia.

RESULTS AND DISCUSSION

We describe the currently knowledge on gene mutations that affect sperm morphology and motility, namely, asthenoteratozoospermia; we also specify the gene mutations that exclusively affect sperm function and activation, resulting in functional asthenozoospermia. We discuss the benefit of this knowledge for patient and couple management, in terms of genetic counselling and diagnosis of male infertility as a sole phenotype or in association with ciliary defects. Last, we discuss the current strategies that have been initiated for the development of potential therapeutical and contraceptive strategies targeting genes that are essential for sperm function and activation.

Olfactory Dysfunction in Primary Ciliary Dyskinesia

Objective

Individuals with primary ciliary dyskinesia (PCD) frequently report olfactory dysfunction, yet this deficit is poorly documented. The purpose of this study was to characterize the presence and degree of olfactory dysfunction in PCD compared to controls and determine whether certain PCD genes are associated with worse olfaction.

Study Design

A prospective cohort study.

Setting

Tertiary referral center.

Methods

We administered the University of Pennsylvania Smell Identification Test (UPSIT) to individuals with PCD. Participants were divided into 3 age groups (15-29 years, 30-44 years, and 45+ years) and compared to age- and sex-matched normal controls (n = 2170).

Results

Twenty-nine individuals with PCD (8 males and 21 females) met the criteria (median age: 38 years; interquartile range: 22-47). Only 27.6% of patients with PCD had UPSIT scores within the normosmia range. The UPSIT median scores of each PCD age group were significantly lower than the median scores of the controls (P < .0001 for each age group). UPSIT scores generally worsened with age: mean 33 (mild hyposmia) for 15 to 29 years, 26.8 (moderate hyposmia) for 30 to 44 years, and 20.9 (severe hyposmia) for 45+ years. The most common genes coded were absent inner dynein arm/microtubule disorientation (IDA/MTD) defect (11/24, 45.8%), followed by absent outer dynein arm defect (8/24, 33.3%). The CCDC39 gene (IDA/MTD) was associated with worse olfactory dysfunction.

Conclusion

Individuals with PCD have a substantially higher prevalence and degree of olfactory dysfunction compared to age-matched controls. Our study is the first to report greater olfactory dysfunction with age in PCD patients, highlighting an important area for research.

Therapies Used by Children With Primary Ciliary Dyskinesia: A Natural History Study

INTRODUCTION

Primary ciliary dyskinesia (PCD) management has not been systematically evaluated and is largely empirical.

METHODS

Pediatric participants with PCD were enrolled in a prospective, longitudinal, multicenter, observational study. Therapies were recorded at annual visits and categorized by type. Age-related trends in prevalence of therapies were described by serial cross-sectional analyses. Generalized estimating equations analyzed covariates affecting prevalence of certain therapies and whether these covariates impacted oral antibiotic courses.

RESULTS

A total of 137 participants completed 897 visits over 13 years. All but one received ≥ 1 antibiotic courses during study participation, most often cephalosporins (74%) or amoxicillin-clavulanate (73%). Thirty-one percent reported chronic azithromycin use. Per participant, there was an average of 2.3 (SD = 2.2) oral antibiotic courses annually. The rate of reported antibiotic courses at the 6 United States sites was 2.6 times higher compared to the Canadian site (p < 0.001). As patients got older, they were more likely to report use of amoxicillin-clavulanate (p < 0.001), chronic azithromycin (p < 0.001), fluroquinolones (p < 0.001), inhaled steroids with long-acting beta-agonists (p = 0.010), and hypertonic saline (p < 0.001). Compared to outer dynein arm defects, those with inner dynein arm/microtubular disorganization defects reported increased use of chronic azithromycin (p = 0.011) and inhaled steroids (p = 0.015).

DISCUSSION

Older participants and those with inner dynein arm/microtubular disorganization defects reported more therapies likely due to disease progression and more severe phenotypes, respectively. We report that a wide range of therapies are used in PCD without disease-specific studies defining benefits and risks.

Impact of local anesthesia on ciliary dyskinesia diagnosis by digital high-speed videomicroscopy

This prospective study investigates the impact of local anesthesia on ciliary function in nasal epithelium. The primary objective was to assess whether lidocaine 2% and naphazoline 0.5% nasal spray alter ciliary beat frequency and pattern in subjects undergoing nasal brushing, aiming to enhance primary ciliary dyskinesia (PCD) diagnosis.

HYPOTHESIS

It was hypothesized that local anesthesia administration would not significantly affect ciliary function in nasal epithelium.

STUDY DESIGN

A prospective, simple-blind randomized study was conducted between 2020 and 2023. The study employed digital high-speed videomicroscopy to analyze ciliary beat frequency and pattern.

PATIENT/SUBJECT SELECTION

A cohort of 38 participants was recruited, consisting of 25 healthy volunteers and 13 referred individuals (including seven diagnosed with PCD). Selection criteria ensured the absence of chronic respiratory diseases, recent respiratory tract infections, or regular use of nasal medications.

METHODOLOGY

Participants underwent nasal brushing with administration of lidocaine and naphazoline nasal spray in one nostril and saline in the contralateral nostril. Ciliary beat frequency and pattern were measured using digital high-speed video microscopy.

RESULTS

Nasal spray administration did not significantly alter ciliary beat frequency or pattern compared to saline (p = 0.841 and p = 0.125, respectively). Subgroup analysis revealed consistent results across healthy volunteers, referred patients, and PCD patients.

CONCLUSION

Local anesthesia with lidocaine and naphazoline spray did not affect ciliary function outcomes. These findings support the safe use of these agents in clinical practice for PCD diagnostic procedures. Further research with larger cohorts is warranted for validation.

Comparison of Longitudinal Outcomes in Children with Primary Ciliary Dyskinesia and Cystic Fibrosis

Rationale: Primary ciliary dyskinesia (PCD) and cystic fibrosis (CF) are both genetic diseases of mucociliary clearance resulting in progressive lung disease with onset in early life. PCD is often considered to be milder than CF in childhood, based on minimal evidence. Similar to CF, genotype-phenotype associations exist in PCD; pathogenic variants in CCDC39 and CCDC40, causing inner dynein arm/microtubular defects (IDA/MTD), are associated with more severe disease. Objectives: To compare longitudinal outcomes in matched children with PCD and CF. We hypothesized that children with PCD with IDA/MTD defects would have lower lung function but better nutritional indices than matched children with CF with minimal function genotypes (i.e., those associated with pancreatic insufficiency). Methods: Children with PCD enrolled in a prospective, multicenter, observational study were matched with patients with CF from the Cystic Fibrosis Foundation Patient Registry by birth cohort, age, sex, race/ethnicity, and year of study visit. The association of disease group overall and by severity class (PCD-IDA/MTD vs. all other defects and CF-minimal vs. residual function) with longitudinal outcomes up to age 17 was evaluated with cubic spline mixed effects models. Results: Groups included 136 children with PCD (40 IDA/MTD, 96 other) and 476 with CF (446 minimal function, 30 residual function). Below age 14, the PCD group had similar or lower estimated mean forced expiratory volume in 1 second percent predicted compared with CF (e.g., at age 10, -5.4% predicted lower; 95% confidence interval [CI], -7.7, -3.1). Compared with the CF-minimal function (pancreatic insufficient) group, the PCD-IDA/MTD group had similar body mass index; estimated mean forced expiratory volume in 1 second percent predicted was significantly lower by age 10 (mean difference, -10.6%; 95% CI, -14.7, -6.4), increasing at age 14 (mean difference, -15.7%; 95% CI, -20.3, -11.2). The CF cohort had increased prevalence of Pseudomonas aeruginosa cultured on one or more occasions compared with children with PCD (67% vs. 27%; P < 0.001); there was no difference in the prevalence of P. aeruginosa between children with PCD-IDA/MTD and PCD-other. Conclusions: In childhood, average lung function abnormalities in PCD are not milder than CF, particularly for those with IDA/MTD ciliary defects. New guidelines and treatments to improve outcomes in PCD are urgently needed.

Comparison of respiratory functions, muscle strength, and physical activity among children with primary ciliary dyskinesia with and without Kartagener's syndrome and healthy controls

INTRODUCTION

Kartagener's syndrome (KS), consisting of bronchiectasis, situs inversus totalis, and sinusitis, is a subtype of primary ciliary dyskinesia (PCD). The presence of KS may affect respiratory and physical functions.

PURPOSE

This study aimed to compare respiratory functions, exercise capacity, muscle strength, and physical activity levels among children with PCD with/without KS and healthy peers.

METHODS

Fifteen patients with KS, 23 with PCD without KS, and 27 controls were compared. Pulmonary function, functional exercise capacity (6-minute walk test - 6MWT), maximal inspiratory, expiratory (MIP, MEP), and skeletal muscle strength, inspiratory muscle endurance (IME), and physical activity level were evaluated.

RESULTS

The forced expiratory volume in one second (FEV1) % (p = .009), forced expiratory flow from 25%-75% (FEF25-75%) % (p = .001), MIP (p = .034), MEP (p = .003), 6MWT distance (p = .001), and daily steps (p = .034) were significantly different among the groups. Quadriceps femoris (QF) muscle strength and IME were similar in groups (p ˃ .05). FEV1% (p = .002), FEF25-75% % (p = .001), MIP (p = .027), MEP (p = .001), and 6MWT distance (p = .003) in patients with KS; 6MWT distance (p = .003) in patients with PCD without KS was significantly lower than controls.

CONCLUSION

The presence of KS affects pulmonary function, respiratory muscle strength, and physical activity more. Exercise capacity and physical activity levels are decreased, inspiratory muscle endurance and QF muscle strength are preserved in patients with KS and PCD without KS. Kartagener's syndrome further impairs pulmonary and extrapulmonary outcomes; the reasons should be investigated, and the necessity of rehabilitation approaches that will prevent deterioration come to the fore.

Lung ultrasound in children with primary ciliary dyskinesia or cystic fibrosis

INTRODUCTION

Primary ciliary dyskinesia (PCD) and cystic fibrosis (CF) are respiratory conditions requiring regular chest radiography (CXR) surveillance to monitor pulmonary disease. However, CXR is insensitive for lung disease in CF and PCD. Lung ultrasound (LU) is a radiation-free alternative showing good correlation with severity of lung disease in CF but has not been studied in PCD.

METHOD

Standardized, six-zone LU studies and CXR were performed on a convenience sample of children with PCD or CF during a single visit when well. LU studies were graded using the LU scoring system, while CXR studies received a modified Chrispin-Norman score. Scores were correlated with clinical outcomes.

RESULT

Data from 30 patients with PCD and 30 with CF (median age PCD 11.5 years, CF 9.1 years) with overall mild pulmonary disease (PCD median FEV1 90% predicted, CF FEV1 100%) were analyzed. LU abnormalities appear in 11/30 (36%) patients with PCD and 9/30 (30%) with CF. Sensitivity, specificity, positive predictive, and negative predictive values for abnormal LU compared to the gold standard of CXR are 42%, 61%, 42%, and 61% in PCD, and 44%, 81%, 50%, and 77% in CF, respectively. Correlation between LU and CXR scores are poor for both diseases (PCD r = -0.1288, p = 0.4977; CF r = 0.0343, p = 0.8571), and LU score does not correlate with clinical outcomes in PCD.

CONCLUSION

The correlation of LU findings with CXR surveillance studies is poor in patients with mild disease burdens from PCD or CF, and LU scores do not correlate with clinical outcomes in PCD.

Recognizing clinical features of primary ciliary dyskinesia in the perinatal period

Primary ciliary dyskinesia (PCD) is a rare, motile ciliopathy inherited through mostly autosomal recessive variants that results in chronic ear, sinus, and respiratory disease. Despite neonatal respiratory distress being a common presenting symptom in term infants with PCD, the diagnosis is often delayed due to non-familiarity of neonatal caregivers with phenotypic and diagnostic features of this disease. Organ laterality defects, prenatal cerebral ventriculomegaly, and a family history of suppurative respiratory disease may occur in PCD and should prompt neonatal testing for this condition. In this review of neonatal PCD diagnoses in a large PCD clinic, prevalence and details of neonatal PCD issues are presented, highlighting the typically delayed onset of neonatal respiratory distress and lobar atelectasis on chest radiography, specific presentations in premature neonates, and responses to perinatal therapies.

Impact of General Anesthesia on Ciliary Functional Analysis by Digital High-Speed Videomicroscopy in Suspected Primary Ciliary Dyskinesia

Digital high-speed videomicroscopy (DHSV) is a crucial tool for evaluating ciliary function in children suspected of primary ciliary dyskinesia (PCD). However, until now, samples are taken without anesthesia due to uncertainty about its effect on ciliary function and DHSV interpretation. This study aimed to investigate the impact of general anesthesia on ciliary functional analysis by DHSV in a series of three patients listed for ENT surgeries, which could improve diagnostic procedures for pediatric patients. Patient 1 (7-year-old girl) underwent adenotonsillectomy and tympanostomy placement tube, while patients 2 (17-month-old boy) and 3 (15-month-old girl) underwent adenoidectomy and tympanostomy placement tube. All patients underwent nasal brushing before general anesthesia (control sample). Experimental samples were taken in the contralateral nostril at the time of equilibration of the anesthetic agents (sevoflurane, propofol, sufentanil). Ciliary beat frequency and pattern were measured using digital high-speed videomicroscopy. Our findings highlighted the variability of respiratory ciliary function under general anesthesia among individuals. Our results emphasize the need for caution when interpreting ciliary function data obtained during general anesthesia. Further research with larger cohorts is warranted for validation.

Alexithymia in primary ciliary dyskinesia

OBJECTIVE

Recent evidence suggests that alexithymic deficits in emotional processing may also affect physical health, and alexithymia may also be associated with organic disorders. The emotional well-being of patients with primary ciliary dyskinesia (PCD) is often negatively affected by uncertainty about the prognosis, lack of ongoing medical care, and lack of symptom control. This study aims to evaluate the frequency of alexithymia and its possible impact on the management of childhood PCD.

MATERIALS AND METHODS

Subjects were recruited from patients with PCD and healthy volunteers aged 8-18 years. The questionnaire included sociodemographic characteristics and self-report scales. Data were compared between patient and control groups.

RESULTS

In the >14 years of age group, the total Toronto Alexithymia Scale (TAS-20) score was significantly higher in the patients (56.60 ± 13.01) compared to the control group (46.47 ± 7.50) (p = .007). There were 6 (30) patients with a TAS-20 score ≥61. There was a significant correlation between TAS-20 and Pediatric Quality of Life (PedsQL) score (child), but no correlation between TAS-20 and Kovacs Children Depression Inventory (CDI) and PedsQL score (parents). The TAS-20 score was significantly higher in patients with bronchiectasis (p = .035), nasal polyps (p = .045), and siblings with PCD (p = .001). Furthermore, the TAS-20 score had a significant negative correlation with pulmonary function tests.

CONCLUSION

Although this study is based on limited data from a single center and cannot be generalized to all PCD patient communities, our results show that PCD patients are more likely to have alexithymia compared to healthy controls and highlight the need to evaluate for alexithymia in patients with PCD. It is important for pediatric pulmonologists to have a thorough knowledge of the alexithymic features associated with PCD and to refer patients to pediatric psychiatry when necessary, especially in patients who are noncompliant with treatment protocols.

Delayed Diagnosis of Primary Ciliary Dyskinesia in Low-Middle-Income Countries: The Clinical Value of Nasal Nitric Oxide

Primary ciliary dyskinesia (PCD) is a rare lung disease that causes chronic oto-sino-pulmonary disease with irreversible lung damage. Several diagnostic methods exist, but electron microscopy (EM) is the most accurate tool, as it visualizes alterations in the axonemal ultrastructure; however, some patients may present a normal ciliary structure. Therefore, other diagnostic methods have been promoted, such as genetic studies or immunofluorescence of specific markers; nonetheless, they are not very accessible and expensive and even present a high level of false negatives. The quantification of nasal nitric oxide (nNO) has been a well-known tool for decades for the screening of this pathology, and recent studies have highlighted its high predictive value in the diagnosis of PCD, as it is a rapid tool in its processing, execution, and accessibility, especially in countries with limited health resources. We present the case of a patient with respiratory symptoms since childhood and extensive lung damage (cystic bronchiectasis); due to lack of access to EM or immunofluorescence, determinations of nNO were performed and found to be compatible with PCD.

Epidemiology of bronchiectasis

Bronchiectasis is a chronic respiratory disease characterised by permanent enlargement of the airways associated with cough, sputum production and a history of pulmonary exacerbations. In the past few years, incidence and prevalence of bronchiectasis have increased worldwide, possibly due to advances in imaging techniques and disease awareness, leading to increased socioeconomic burden and healthcare costs. Consistently, a mortality increase in bronchiectasis patient cohorts has been demonstrated in certain areas of the globe, with mortality rates of 16-24.8% over 4-5 years of follow-up. However, heterogeneity in epidemiological data is consistent, as reported prevalence in the general population ranges from 52.3 to more than 1000 per 100 000. Methodological flaws in the designs of available studies are likely to underestimate the proportion of people suffering from this condition worldwide and comparisons between different areas of the globe might be unreliable due to different assessment methods or local implementation of the same method in different contexts. Differences in disease severity associated with diverse geographical distribution of aetiologies, comorbidities and microbiology might explain an additional quota of heterogeneity. Finally, limited access to care in certain geographical areas is associated with both underestimation of the disease and increased severity and mortality. The aim of this review is to provide a snapshot of available real-world epidemiological data describing incidence and prevalence of bronchiectasis in the general population. Furthermore, data on mortality, healthcare burden and high-risk populations are provided. Finally, an analysis of the geographical distribution of determinants contributing to differences in bronchiectasis epidemiology is offered.

Ciliary Function, Antigen Stasis and Asthma

The prevalence of asthma exceeds 3% of the population. Asthma is observed to be more common in children following severe viral lower respiratory illnesses that affect ciliary function, but mechanisms linking ciliary function to asthma pathogenesis have been obscure. Recent data regarding primary ciliary dyskinesia (PCD) may help us to understand the association. Here, I will review what is known about the relationship between ciliary function and asthma. PCD is caused by pathologic variants in over 50 different genes that affect the structure and function of motile cilia. At the cellular level, a characteristic feature shared by most PCD patients is that antigens and other particles are not cleared from the epithelial surface. Poor antigen clearance results in pro-oxidant pathway activation and airway epithelial damage and may predispose PCD patients to DUOX1- and IL33-mediated asthma. Secondary ciliary dysfunction, such as that caused by viruses or by smoking, can also contribute to asthma development. Moreover, variants in genes that affect the function of cilia can be associated with poor lung function, even in the absence of PCD, and with increased asthma severity. The role of antigen stasis on the surface of dysfunctional airway cilia in the pathophysiology of asthma is a novel area for research, because specific airway clearance techniques and other therapeutic interventions, such as antioxidants, could be of value in preventing the development of asthma.

Innovations in Childhood Interstitial and Diffuse Lung Disease

Children's interstitial and diffuse lung diseases (chILDs) are a heterogenous and diverse group of lung disorders presenting during childhood. Infants and children with chILD disorders present with respiratory signs and symptoms as well as diffuse lung imaging abnormalities. ChILD disorders are associated with significant health care resource utilization and high morbidity and mortality. The care of patients with chILD has been improved through multidisciplinary care, multicenter collaboration, and the establishment of patient research networks in the United Stated and abroad. This review details past and current innovations in the diagnosis and clinical care of children with chILD.

Advanced Diagnostic and Therapeutic Bronchoscopy in Pediatrics

Advanced diagnostic and therapeutic flexible bronchoscopy in children is a rapidly evolving field. Recent advances in technology and awareness of indications, risks, and benefits by pediatric providers have greatly increased the use of advanced techniques in children. This review highlights advanced diagnostic procedures including assessment of endobronchial lesions, mediastinal/hilar masses, and peripheral lung nodules as well as therapeutic techniques for restoring airway lumen patency, managing persistent air leaks, and treating tracheoesophageal fistulas in children as well as the potential to spare these patients more invasive procedures.

Respiratory Aspects of Primary Ciliary Dyskinesia

This review article explores the respiratory aspects of primary ciliary dyskinesia (PCD), a rare, heterogenous, genetic disorder characterized by impaired motile ciliary function. It discusses the clinical diagnosis and management strategies for PCD-related respiratory disease, including chronic sinusitis, otitis media with effusion, recurrent pneumonia, and bronchiectasis. The review emphasizes the need for a multidisciplinary approach to optimize care and clinical trials to improve outcomes in individuals with PCD, highlighting the importance of accurate diagnosis.

Characterization of pathogenic genetic variants in Russian patients with primary ciliary dyskinesia using gene panel sequencing and transcript analysis

BACKGROUND

Primary ciliary dyskinesia (PCD) is a group of rare genetically heterogeneous disorders caused by defective cilia and flagella motility. The clinical phenotype of PCD patients commonly includes chronic oto-sino-pulmonary disease, infertility, and, in about half of cases, laterality defects due to randomization of left-right body asymmetry. To date, pathogenic variants in more than 50 genes responsible for motile cilia structure and assembly have been reported in such patients. While multiple population-specific mutations have been described in PCD cohorts from different countries, the data on genetic spectrum of PCD in Russian population are still extremely limited.

RESULTS

The present study provides a comprehensive clinical and genetic characterization of 21 Russian families with PCD living in various country regions. Anomalies of ciliary beating in patients` respiratory epithelial cells were confirmed by high-speed video microscopy. In the most cases, custom-designed panel sequencing allowed to uncover causative variants in well-known or rarely mentioned PCD-related genes, including DNAH5, DNAH11, CFAP300, LRRC6, ZMYND10, CCDC103, HYDIN, ODAD4, DNAL1, and OFD1. The variations comprised common mutations, as well as novel genetic variants, some of which probably specific for Russian patients. Additional targeted analysis of mRNA transcripts from ciliated cells enabled us to specify functional effects of newly identified genetic variants in DNAH5 (c.2052+3G>T, c.3599-2A>G), HYDIN (c.10949-2A>G, c.1797C>G), and ZMYND10 (c.510+1G>C) on splicing process. In particular, the splice site variant c.2052+3G>T, detected in four unrelated families, resulted in skipping of exon 14 in DNAH5 transcripts and, according to haplotype analysis of affected probands, was proposed as an ancestral founder mutation in Udmurt population.

CONCLUSIONS

The reported data provide a vital insight into genetic background of primary ciliary dyskinesia in the Russian population. The findings clearly illustrate the utility of gene panel sequencing coupled with transcriptional analysis in identification and clinical interpretation of novel genetic variants.

Development and Initial Characterization of Pigs with DNAI1 Mutations and Primary Ciliary Dyskinesia

Mutations in more than 50 different genes cause primary ciliary dyskinesia (PCD) by disrupting the activity of motile cilia that facilitate mucociliary transport (MCT). Knowledge of PCD has come from studies identifying disease-causing mutations, characterizing structural cilia abnormalities, finding genotype-phenotype relationships, and studying the cell biology of cilia. Despite these important findings, we still lack effective treatments and people with PCD have significant pulmonary impairment. As with many other diseases, a better understanding of pathogenic mechanisms may lead to effective treatments. To pursue disease mechanisms, we used CRISPR-Cas9 to develop a PCD pig with a disrupted DNAI1 gene. PCD pig airway cilia lacked the outer dynein arm and had impaired beating. MCT was impaired under both baseline conditions and after cholinergic stimulation in PCD pigs. Neonatal PCD pigs developed neonatal respiratory distress with evidence of atelectasis, air trapping, and airway mucus obstruction. Despite airway mucus accumulation, lung bacterial counts were similar between neonatal wild-type and PCD pigs. Sinonasal disease was present in all neonatal PCD pigs. Older PCD pigs developed worsening airway mucus obstruction, inflammation, and bacterial infection. This pig model closely mimics the disease phenotype seen in people with PCD and can be used to better understand the pathophysiology of PCD airway disease.

Evaluation of Open-Source Ciliary Analysis Software in Primary Ciliary Dyskinesia: A Comparative Assessment

Primary Ciliary Dyskinesia (PCD) is a rare genetic disorder characterized by alterations in motile cilia function. The diagnosis of PCD is challenging due to the lack of standardized methods in clinical practice. High-speed video microscopy analysis (HSVA) directly evaluates ciliary beat frequency (CBF) in PCD. Recently, open-source ciliary analysis software applications have shown promise in measuring CBF accurately. However, there is limited knowledge about the performance of different software applications, creating a gap in understanding their comparative effectiveness in measuring CBF in PCD. We compared two open-source software applications, CiliarMove (v219) and Cilialyzer (v1.2.1-b3098cb), against the manual count method. We used high-speed videos of nasal ciliary brush samples from PCD RSPH4A-positive (PCD (RSPH4A)) patients and healthy controls. All three methods showed lower median CBF values for patients with PCD (RSPH4A) than in healthy controls. CiliarMove and Cilialyzer identified lower CBF in patients with PCD (RSPH4A), similarly to the manual count. Cilialyzer, CiliarMove, and manual count methods demonstrated statistical significance (p-value < 0.0001) in the difference of median CBF values between patients with PCD (RSPH4A) and healthy controls. Correlation coefficients between the manual count values against both software methods demonstrated positive linear relationships. These findings support the utility of open-source software-based analysis tools. Further studies are needed to validate these findings with other genetic variants and identify the optimal software for accurate CBF measurement in patients with PCD.

Beyond Bronchopulmonary Dysplasia: A Comprehensive Review of Chronic Lung Diseases in Neonates

In neonates, pulmonary diseases such as bronchopulmonary dysplasia and other chronic lung diseases (CLDs) pose significant challenges due to their complexity and high degree of morbidity and mortality. This review discusses the etiology, pathophysiology, clinical presentation, and diagnostic criteria for these conditions, as well as current management strategies. The review also highlights recent advancements in understanding the pathophysiology of these diseases and evolving strategies for their management, including gene therapy and stem cell treatments. We emphasize how supportive care is useful in managing these diseases and underscore the importance of a multidisciplinary approach. Notably, we discuss the emerging role of personalized medicine, enabled by advances in genomics and precision therapeutics, in tailoring therapy according to an individual's genetic, biochemical, and lifestyle factors. We conclude with a discussion on future directions in research and treatment, emphasizing the importance of furthering our understanding of these conditions, improving diagnostic criteria, and exploring targeted treatment modalities. The review underscores the need for multicentric and longitudinal studies to improve preventative strategies and better understand long-term outcomes. Ultimately, a comprehensive, innovative, and patient-centered approach can enhance the quality of care and outcomes for neonates with CLDs.

Estimates of primary ciliary dyskinesia prevalence: a scoping review

Background

Primary ciliary dyskinesia (PCD) is a rare multisystem genetic disease caused by dysfunctional motile cilia. Despite PCD being the second most common inherited airway disease after cystic fibrosis, PCD continues to be under-recognised globally owing to nonspecific clinical features and the lack of a gold standard diagnostic test. Commonly repeated prevalence estimates range from one in 10 000 to one in 20 000, based on regional epidemiological studies with known limitations. The purpose of this scoping review was to appraise the PCD literature, to determine the best available global PCD prevalence estimate and to inform the reader about the potential unmet health service needs in PCD. The primary objective of the present study was to systematically review the literature about PCD prevalence estimates.

Methods

A scoping review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) methodology. Included studies estimated PCD prevalence and used cohort, clinical or genomic data. Case reports, conference abstracts, review articles, animal studies or non-English articles were excluded.

Results

A literature review identified 3484 unique abstracts; 34 underwent full-text review and eight met the inclusion/exclusion criteria. Seven articles were based on epidemiological studies of specific geographical regions and provided prevalence estimates that ranged from approximately one to 44.1 in 100 000. Only one study estimated global prevalence, using two large genomic databases, and calculated it to be ∼13.2 in 100 000 (based on pathogenic variants in 29 disease-causing genes).

Conclusions

A population-based genomic approach for estimating global prevalence has found that PCD is much more prevalent than previously cited in the literature. This highlights the potential unmet health service needs of people living with PCD.

Primary Ciliary Dyskinesia: A Clinical Review

Primary ciliary dyskinesia (PCD) is a rare, genetically heterogeneous, motile ciliopathy, characterized by neonatal respiratory distress, recurrent upper and lower respiratory tract infections, subfertility, and laterality defects. Diagnosis relies on a combination of tests for confirmation, including nasal nitric oxide (nNO) measurements, high-speed videomicroscopy analysis (HSVMA), immunofluorescent staining, axonemal ultrastructure analysis via transmission electron microscopy (TEM), and genetic testing. Notably, there is no single gold standard confirmatory or exclusionary test. Currently, 54 causative genes involved in cilia assembly, structure, and function have been linked to PCD; this rare disease has a spectrum of clinical manifestations and emerging genotype-phenotype relationships. In this review, we provide an overview of the structure and function of motile cilia, the emerging genetics and pathophysiology of this rare disease, as well as clinical features associated with motile ciliopathies, novel diagnostic tools, and updates on genotype-phenotype relationships in PCD.

Kartagener's Syndrome: A Case Series

Kartagener's syndrome is an uncommon autosomal recessive ciliary dyskinesia. It combines a triad comprised of bronchiectasis, chronic sinusitis, and situs inversus. This work aims to describe the clinical and paraclinical aspects of primary ciliary dyskinesia using Kartagener's syndrome as a model and to highlight the difficulties of confirming the diagnosis in our context. We report four observations (three boys and one girl with an average age of 10 years) of Kartagener's syndrome collected in the department of pediatric pneumo-allergology. Chronic bronchorrhea and otorhinolaryngological manifestations were found in all cases. Signs of neonatal respiratory distress syndrome were found in only one case. One child had dysmorphic facial features suggestive of Noonan's syndrome and conductive hearing loss. Digital hippocratism was found in half of the cases, along with pulmonary crackles and heart sounds perceived on the right. A chest CT scan showed bronchiectasis in all patients and necrotic adenopathy suggestive of tuberculosis in one case. Sinus imaging showed an appearance of pansinusitis. All children had abdominal situs inversus with dextrocardia. They had received antibiotic therapy with amoxicillin-clavulanic acid associated with respiratory physiotherapy. The girl had benefited from a right lobectomy with a follow-up of 18 months and a good evolution. In light of these four observations, Kartagener's syndrome is a rare disease but can be compatible with normal life if the treatment is done early. However, in our context, the difficulty of confirming the diagnosis explains its delay with the risk of progression of pulmonary lesions.

Bronchiectasis management in adults: state of the art and future directions

Formerly regarded as a rare disease, bronchiectasis is increasingly recognised. A renewed interest in this disease has led to significant progress in bronchiectasis research. Randomised clinical trials (RCTs) have demonstrated the benefits of airway clearance techniques, inhaled antibiotics and long-term macrolide therapy in bronchiectasis patients. However, the heterogeneity of bronchiectasis remains one of the most challenging aspects of management. Phenotypes and endotypes of bronchiectasis have been identified to help find "treatable traits" and partially overcome disease complexity. The goals of therapy for bronchiectasis are to reduce the symptom burden, improve quality of life, reduce exacerbations and prevent disease progression. We review the pharmacological and non-pharmacological treatments that can improve mucociliary clearance, reduce airway inflammation and tackle airway infection, the key pathophysiological features of bronchiectasis. There are also promising treatments in development for the management of bronchiectasis, including novel anti-inflammatory therapies. This review provides a critical update on the management of bronchiectasis focusing on treatable traits and recent RCTs.

Primary Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is a rare, genetic disease characterized by dysfunctional motile cilia and abnormal mucociliary clearance, resulting in chronic sino-oto-pulmonary disease, neonatal respiratory distress, subfertility, and organ laterality defects. Over the past 2 decades, research and international collaborations have led to an improved understanding of disease prevalence, classic and variable phenotypes, novel diagnostics, genotype-phenotype correlations, long term morbidity, and innovative therapeutics. However, PCD is often underrecognized in clinical settings and the recent analyses of genetic databases suggest that only a fraction of these patients are being accurately diagnosed. Knowledge of significant advancements, from pathophysiology to the expanded range of clinical manifestations, will have important clinical impacts. These may include increasing disease recognition, improving diagnostic testing and management, and establishing an adequate pool of affected patients to enroll in upcoming clinical therapeutic trials. The objective of this state-of-the-art review is for readers to gain a greater understanding of the clinical spectrum of motile ciliopathies, cutting-edge diagnostic practices, emerging genotype-phenotype associations, and currently accepted management of people with PCD.

A novel homozygous RSPH4A variant in a family with primary ciliary dyskinesia and literature review

Introduction: Primary ciliary dyskinesia (PCD) is a rare heterogeneous disease caused by abnormalities in motile cilia. In this case report, we first analyzed the clinical and genetic data of a proband who was suspected of having PCD on the basis of her clinical and radiological findings. Methods: Whole-exome sequencing was performed, and a variant in the RSPH4A gene was identified in the proband. Sanger sequencing was used for validation of RSPH4A variants in the proband, her sister, her daughter and her parents. Finally, the phenotypic features of the patient were analyzed, and the current literature was reviewed to better understand the gene variants in PCD related to hearing loss and the clinical manifestations of the RSPH4A variant in PCD. Results: The chief clinical symptoms of this proband included gradual mixed hearing loss, otitis media, anosmia, sinusitis, recurrent cough and infertility. Her DNA sequencing revealed a novel homozygous T to C transition at position 1321 within exon 3 of RSPH4A according to genetic testing results. This variant had never been reported before. The homozygous variant resulted in an amino acid substitution of tryptophan by arginine at position 441 (p.Trp441Arg). The same variant was also found in the proband's sister, and a heterozygous pathogenic variant was identified among immediate family members, including the proband's daughter and parents. Discussion: A literature review showed that 16 pathogenic variants in RSPH4A have been reported. Hearing loss had only been observed in patients with the RSPH4A (c.921+3_6delAAGT) splice site mutation, and the specific type of hearing loss was not described.

FOXJ1 Variants Causing Primary Ciliary Dyskinesia with Hydrocephalus: A Case Report from Japan

Primary ciliary dyskinesia (PCD) is a genetic disease characterized by motile cilia dysfunction, mostly inherited in an autosomal recessive or X-linked manner. We herein report a 29-year-old woman with PCD caused by a heterozygous frameshift mutation due to a single nucleotide deletion in exon 3 of FOXJ1. Heterozygous de novo mutations in FOXJ1 have been reported as an autosomal-dominant cause of PCD. The patient had situs inversus, congenital heart disease, infertility, and hydrocephalus. However, the nasal nitric oxide level was normal. Long-term macrolide therapy was remarkably effective. This is the first case report of PCD caused by a FOXJ1 variant in Japan.

Ciliary Functional Analysis in Chronic Rhinosinusitis with Polyps after Multimodal Intervention: Oral Corticosteroid, Functional Endoscopic Sinus Surgery, and Omalizumab Injection

In her late 50 s, a woman with a medical history of endoscopic sinus surgery for chronic rhinosinusitis with nasal polyps (CRSwNP) experienced a relapse of nasal polyps, significantly impacting her breathing and sense of smell. She underwent a multifaceted treatment approach, including oral corticosteroids, functional endoscopic sinus surgery, and omalizumab injections. Digital high-speed videomicroscopy (DHSV) revealed only partial improvement in ciliary beat pattern and ciliary beat frequency with oral corticosteroid treatment, while significant improvement in these ciliary parameters was observed with omalizumab injections. Furthermore, administration of omalizumab resulted in a decrease in her SNOT-22 (Sinonasal Outcome Test 22) score. Notably, this case report represents the first study investigating ciliary function using DHSV in a patient treated with omalizumab.

Situs Ambiguus Is Associated With Adverse Clinical Outcomes in Children With Primary Ciliary Dyskinesia

BACKGROUND

Primary ciliary dyskinesia (PCD) is a rare disorder of motile cilia associated with situs abnormalities. At least 12% of patients with PCD have situs ambiguus (SA), including organ laterality defects falling outside normal arrangement (situs solitus [SS]) or mirror image inversion (situs inversus totalis [SIT]).

RESEARCH QUESTION

Do patients with PCD and SA achieve worse clinical outcomes compared with those with SS or SIT?

STUDY DESIGN AND METHODS

This cross-sectional, multicenter study evaluated participants aged 21 years or younger with PCD. Participants were classified as having SA, including heterotaxy, or not having SA (SS or SIT). Markers of disease severity were compared between situs groups, adjusting for age at enrollment and severe CCDC39 or CCDC40 genotype, using generalized linear models and logistic and Poisson regression.

RESULTS

In 397 participants with PCD (mean age, 8.4 years; range, 0.1-21), 42 patients were classified as having SA, including 16 patients (38%) with complex cardiovascular malformations or atrial isomerism, 13 patients (31%) with simple CVM, and 13 patients (31%) without cardiovascular malformations. Of these, 15 patients (36%) underwent cardiac surgery, 24 patients (57%) showed an anatomic spleen abnormality, and seven patients (17%) showed both. The remaining 355 participants did not have SA, including 152 with SIT and 203 with SS. Overall, 70 participants (17%) harbored the severe CCDC39 or CCDC40 genotype. Compared with participants without SA, those with SA showed lower median BMI z scores (P = .03), lower FVC z scores (P = .01), and more hospitalizations and IV antibiotic courses for acute respiratory infections during the 5 years before enrollment (P < .01). Participants with cardiovascular malformations requiring surgery or with anatomic spleen abnormalities showed lower median BMI z scores and more hospitalizations and IV therapies for respiratory illnesses compared with participants without SA.

INTERPRETATION

Children with PCD and SA achieve worse nutritional and pulmonary outcomes with more hospitalizations for acute respiratory illnesses than those with SS or SIT combined. Poor nutrition and increased hospitalizations for respiratory infections in participants with SA and PCD are associated with cardiovascular malformations requiring cardiac surgery, splenic anomalies, or both.

TRIAL REGISTRY

ClinicalTrials.gov; Nos.: NCT02389049 and NCT00323167; URL: www.

CLINICALTRIALS

gov.

Stepwise genetic approach for the diagnosis of primary ciliary dyskinesia in highly consanguineous populations

BACKGROUND

The American Thoracic Society guidelines for the diagnosis of primary ciliary dyskinesia (PCD) consider the presence of a bi-allelic pathogenic variant confirmatory for the diagnosis of PCD, with genetic testing recommended when other confirmatory diagnostic tests are less accessible. We present our experience with genetic testing as first line with a proposed algorithm for high consanguinity populations.

METHODS

Patients with a suspected diagnosis of PCD underwent genetic testing according to a diagnostic algorithm composed of three steps: (1) patients with a previously known causative familial/Bedouin tribal pathogenic variant completed direct testing for a single variant; (2) if the initial test was negative or there was no known pathogenic variant, a PCD genetic panel was completed; (3) if the panel was negative, whole exome sequencing (WES) was completed.

RESULTS

Since the implementation of the protocol, diagnosis was confirmed by genetic testing in 21 patients. The majority of them were of Bedouin origin (81%) and had a positive history of consanguinity (65%). Nine patients (43%) had a sibling with a confirmed diagnosis. Most patients (15/21, 71%) were diagnosed by direct pathogenic variant testing and the remainder by genetic panel (19%) and WES (10%). Disease-causing variants were found in nine genes, with DNAL1 (24%) and DNAAF3, DNAAF5, ZMYND10 (14% each) as the most prevalent ones.

CONCLUSIONS

In highly consanguineous regions, a stepwise genetic testing approach is recommended. This approach may be particularly useful in areas where the ability to obtain confirmatory diagnostic tests through other modalities is less accessible.

Primary ciliary dyskinesia: An update on contemporary diagnosis

KEY POINTS

Primary ciliary dyskinesia (PCD) is a complex diagnosis without a universal diagnostic test Clinicians must have some skepticism of historic diagnoses of PCD Clinicians should consider a diagnosis of PCD in patients with recalcitrant disease.

Late Diagnosis of Kartagener Syndrome in an Adult Female

Kartagener syndrome (KS), also known as primary ciliary dyskinesia, is a rare genetic disorder commonly diagnosed early in childhood. It is characterized by a triad of findings, namely, situs inversus, chronic sinusitis, and bronchiectasis. Here, we present the case of a 73-year-old female who incidentally presented the KS triad during her imaging tests in the emergency department of our institution for COVID-19 symptoms.

Antigen stasis and airway nitrosative stress in human primary ciliary dyskinesia

Nasal nitric oxide (nNO) is low in most patients with primary ciliary dyskinesia (PCD). Decreased ciliary motion could lead to antigen stasis, increasing oxidant production and NO oxidation in the airways. This could both decrease gas phase NO and increase nitrosative stress. We studied primary airway epithelial cells from healthy controls (HCs) and patients with PCD with several different genotypes. We measured antigen clearance in fenestrated membranes exposed apically to the fluorescently labeled antigen Dermatophagoides pteronyssinus (Derp1-f). We immunoblotted for 3-nitrotyrosine (3-NT) and for oxidative response enzymes. We measured headspace NO above primary airway cells without and with a PCD-causing genotype. We measured nNO and exhaled breath condensate (EBC) H2O2 in vivo. Apical Derp1-f was cleared from HC better than from PCD cells. DUOX1 expression was lower in HC than in PCD cells at baseline and after 24-h Derp1-f exposure. HC cells had less 3-NT and NO3- than PCD cells. However, NO consumption by HC cells was less than that by PCD cells; NO loss was prevented by superoxide dismutase (SOD) and by apocynin. nNO was higher in HCs than in patients with PCD. EBC H2O2 was lower in HC than in patients with PCD. The PCD airway epithelium does not optimally clear antigens and is subject to oxidative and nitrosative stress. Oxidation associated with antigen stasis could represent a therapeutic target in PCD, one with convenient monitoring biomarkers.NEW & NOTEWORTHY The PCD airway epithelium does not optimally clear antigens, and antigen exposure can lead to NO oxidation and nitrosative stress. Oxidation caused by antigen stasis could represent a therapeutic target in PCD, and there are convenient monitoring biomarkers.

Advancing Primary Ciliary Dyskinesia Diagnosis through High-Speed Video Microscopy Analysis

Primary ciliary dyskinesia (PCD) is an inherited disorder that impairs motile cilia, essential for respiratory health, with a reported prevalence of 1 in 16,309 within Hispanic populations. Despite 70% of Puerto Rican patients having the RSPH4A [c.921+3_921+6del (intronic)] founder mutation, the characterization of the ciliary dysfunction remains unidentified due to the unavailability of advanced diagnostic modalities like High-Speed Video Microscopy Analysis (HSVA). Our study implemented HSVA for the first time on the island as a tool to better diagnose and characterize the RSPH4A [c.921+3_921+6del (intronic)] founder mutation in Puerto Rican patients. By applying HSVA, we analyzed the ciliary beat frequency (CBF) and pattern (CBP) in native Puerto Rican patients with PCD. Our results showed decreased CBF and a rotational CBP linked to the RSPH4A founder mutation in Puerto Ricans, presenting a novel diagnostic marker that could be implemented as an axillary test into the PCD diagnosis algorithm in Puerto Rico. The integration of HSVA technology in Puerto Rico substantially enhances the PCD evaluation and diagnosis framework, facilitating prompt detection and early intervention for improved disease management. This initiative, demonstrating the potential of HSVA as an adjunctive test within the PCD diagnostic algorithm, could serve as a blueprint for analogous developments throughout Latin America.

The airway microbiota in siblings with primary ciliary dyskinesia: Related factors and correlation with clinical characteristics

OBJECTIVES-AIM

We aimed to show the composition and structure of and explore affecting factors on airway microbiota in primary ciliary dyskinesia (PCD) patients using culture-independent techniques.

METHOD

A cross-sectional observational study was performed. We recruited 14 PCD patients (seven pairs of siblings) and nine parents. Bacterial rDNA was extracted from sputum and nasal samples. Sputum samples were also inoculated on suitable bacteriological media.

RESULTS

Thirty-three separate genera were detected in sputum samples of PCD patients, and 41 were in nasal samples of parents. The detected genera were dominated by phyla Proteobacteria in PCD patients and their parents. Culture-dependent analyses could not detect many of the bacterial species detected with culture-independent analyses. There were no significant differences in alpha diversity between the siblings' pairs, and siblings' samples did not cluster together nearly as strongly as nonsiblings' samples. Patients who had no new complaints and no bacterial growth with the culture-dependent method at the time of study and patients who had no Haemophilus influenzae growth in the previous year had a significantly greater diversity (p < .05). Microbiota communities tended to cluster together by age, pulmonary exacerbation status, the existence of at least one H. influenzae growth with culture-dependent analyses in the previous year, and forced expiratory volume in 1 sec z and FEF25-75 z-scores.

CONCLUSION

The airway microbiota of patients with PCD have presented more diverse bacterial communities than had been indicated with culture-dependent methods. The study identifies relationships between bacterial airway microbiota composition and the clinical measures of patients. Sibling pairs have no more community similarities than nonsibling PCD patients. Our results may indicate that the patients' clinical characteristics, which determine the disease severity, might affect the PCD microbiome.

Fertility care among people with primary ciliary dyskinesia

INTRODUCTION

Fertility care is important for people living with primary ciliary dyskinesia (PCD) who are at increased risk of fertility problems. We investigated fertility care in an international participatory study.

METHODS

Participants of the COVID-PCD study completed an online questionnaire addressing fertility issues. We used logistic regression to study factors associated with fertility specialist visits.

RESULTS

Among 384 respondents (response rate 53%), 266 were adults (median age 44 years, interquartile range [IQR]: 33-54, 68% female), 16 adolescents, and 102 parents of children with PCD. Only half of adult participants (128; 48%) received care from fertility specialists at a median age of 30 years (IQR: 27-33)-a median of 10 years after PCD diagnosis. Only 12% were referred to fertility specialists by their PCD physician. Fertility specialist visits were reported more often by adults with pregnancy attempts (odds ratio [OR]: 9.1, 95% confidence interval [CI]: 3.8-23.6) and among people who reported fertility as important for them (OR: 5.9, 95% CI: 2.6-14.6) and less often by females (OR: 0.4, 95% CI: 0.2-0.8). Only 56% of participants who talked with healthcare professionals about fertility were satisfied with information they received. They expressed needs for more comprehensive fertility information and reported dissatisfaction with physician knowledge about PCD and fertility.

CONCLUSION

People with PCD are inconsistently referred to fertility specialists. We recommend care from fertility specialists become standard in routine PCD care, and that PCD physicians provide initial fertility information either at diagnosis or no later than transition to adult care.

Safety and efficacy of the epithelial sodium channel blocker idrevloride in people with primary ciliary dyskinesia (CLEAN-PCD): a multinational, phase 2, randomised, double-blind, placebo-controlled crossover trial

BACKGROUND

Mucociliary clearance is dysfunctional in people with primary ciliary dyskinesia, resulting in the accumulation of dehydrated mucus in the airways that is difficult to clear. We undertook a study to assess the benefit on lung function of treatment with a nebulised epithelial sodium channel (ENaC) blocker, idrevloride, with or without hypertonic saline, in people with primary ciliary dyskinesia.

METHODS

The CLEAN-PCD trial was a phase 2, randomised, double-blind, placebo-controlled crossover trial conducted at 32 tertiary adult and paediatric care centres and university hospitals in Canada, Denmark, Germany, Italy, the Netherlands, Poland, the UK, and the USA. People with a confirmed diagnosis of primary ciliary dyskinesia, aged 12 years or older, with a percentage of predicted FEV1 (ppFEV1) in the range of 40% to <90%, were randomly assigned in a 2:2:1:1 ratio (block size=6), stratified by ppFEV1 at screening, to one of four sequences: (1) idrevloride in hypertonic saline in treatment period 1 then hypertonic saline in treatment period 2; (2) hypertonic saline in treatment period 1 then idrevloride in hypertonic saline in treatment period 2; (3) idrevloride in treatment period 1 then placebo in treatment period 2; and (4) placebo in treatment period 1 then idrevloride in treatment period 2. The idrevloride dose was 85 μg and hypertonic saline was 4·2% NaCl. 3 mL of each study treatment was nebulised twice daily for 28 days in treatment periods 1 and 2; the two 28-day treatment periods were separated by a 28-day washout period. The primary endpoint was absolute change from baseline in ppFEV1 after 28 days. Safety assessments and reports of adverse events were made at clinic visits during each treatment period and by a follow-up telephone call 28 days after the last dose of study drug. Additionally, adverse events could be reported at a follow-up telephone call 3 days after the start of dosing and as they arose. Participants who received at least one dose of study drug were included in the safety analyses (safety set), and those who also had spirometry data were included in the efficacy analyses (full analysis set). The completed study is registered (EudraCT 2015-004917-26; ClinicalTrials.govNCT02871778).

FINDINGS

Between Sep 14, 2016, and May 31, 2018, 216 patients were screened and 123 were randomly assigned to one of four crossover sequences. Across the two treatment periods, treatment with idrevloride in hypertonic saline was initiated in 80 patients and completed in 78 patients (all 78 had data available and were included in the analysis); hypertonic saline initiated in 81 patients and completed in 76 patients (75 had data available and were included in the analysis); idrevloride initiated in 37 patients and completed in 35 patients (34 had data available and were included in the analysis); and placebo initiated in 36 patients and completed in 34 patients (all 34 had data available and were included in the analysis). Greater absolute increases in ppFEV1 from baseline to 28 days of treatment were seen with idrevloride in hypertonic saline (least-squares mean absolute change from baseline 1·0 percentage points, 95% CI -0·4 to 2·4) than with hypertonic saline alone (least-squares mean absolute change from baseline of -0·5 percentage points, -2·0 to 0·9; difference 1·5 percentage points, 95% CI <0·1 to 3·0; p=0·044). There was no significant difference in ppFEV1 for the parallel comparison of idrevloride in hypertonic saline compared with placebo or the crossover comparison of idrevloride with placebo. Adverse events were similar across treatments (57 to 65% of patients). Cough occurred in a greater proportion of participants during treatments that contained idrevloride or hypertonic saline compared with placebo, and oropharyngeal pain occurred in a greater proportion of participants during idrevloride treatments than during treatment with hypertonic saline alone or placebo, whereas chest discomfort was more common during treatments that included hypertonic saline.

INTERPRETATION

In this phase 2 crossover study, idrevloride in hypertonic saline was safe and associated with improved lung function over a 28-day period in people with primary ciliary dyskinesia compared with hypertonic saline alone. Larger, longer clinical studies are warranted to explore the potential benefits of idrevloride in combination with hypertonic saline in people with primary ciliary dyskinesia.

FUNDING

Parion Sciences, under agreement with Vertex Pharmaceuticals.

Application of roc-analysis to assess the quality of predicting the risk of chronic rhinosinusitis recurrence

OBJECTIVE

Aim: To propose a new, original approach to assessing the quality of a multivariate regression model for predicting the risk of recurrence in patients with chronic rhinosinusitis based on ROC analysis with the construction of appropriate curves, estimating the area under them, as well as calculating the sensitivity, accuracy, specificity, and predictive value of a positive and negative classification results, the likelihood ratio of positive and negative patient detection results.

PATIENTS AND METHODS

Materials and Methods: 204 patients aged with a diagnosis of chronic rhinosinusitis were examined.

RESULTS

Results: To build a multivariate regression model 14 probable factors of chronic rhinosinusitis occurrence were selected to determine the diagnostic value of the proposed model we calculate the sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), the likelihood ratio of a positive test (LR+), the likelihood ratio of a negative test (LR-) and prediction accuracy % of the proposed mathematical model. In order to determine the prognostic value of the risk ratio of CRS recurrence model, ROC- analysis was performed, ROC curves were obtained.

CONCLUSION

Conclusions: The multivariate regression model makes it possible to predict potential complications and the possibility of disease recurrence. The construction of ROC-curves allows us to assert the excellent classification quality of chronic rhinosinusitis recurrence.