Do Causes Influence Functional Aspects and Quality of Life in Patients with Nonfibrocystic Bronchiectasis?

Background: The denomination of noncystic fibrosis bronchiectasis (NCFB) includes several causes, and differences may be expected between the patient subgroups regarding age, comorbidities, and clinical and functional evolution. This study sought to identify the main causes of NCFB in a cohort of stable adult patients and to investigate whether such conditions would be different in their clinical, functional, and quality of life aspects. Methods: Between 2017 and 2019, all active patients with NCFB were prospectively evaluated searching for clinical data, past medical history, dyspnea severity grading, quality of life data, microbiological profile, and lung function (spirometry and six-minute walk test). Results: There was a female predominance; mean age was 54.7 years. Causes were identified in 82% of the patients, the most frequent being postinfections (n = 39), ciliary dyskinesia (CD) (n = 32), and chronic obstructive pulmonary disease (COPD) (n = 29). COPD patients were older, more often smokers (or former smokers) and with more comorbidities; they also had worse lung function (spirometry and oxygenation) and showed worse performance in the six-minute walk test (6MWT) (walked distance and exercise-induced hypoxemia). Considering the degree of dyspnea, in the more symptomatic group, patients had higher scores in the three domains and total score in SGRQ, besides having more exacerbations and more patients in home oxygen therapy. Conclusions: Causes most identified were postinfections, CD, and COPD. Patients with COPD are older and have worse pulmonary function and more comorbidities. The most symptomatic patients are clinically and functionally more severe, besides having worse quality of life.

Pregnancy and delivery in a patient with a Fontan circulation and primary ciliary dyskinesia: A case report.

A patient had primary ciliary dyskinesia with a complex cardiac malformation. As a child, she had benefited from a Fontan surgery to maintain a proper cardiac function. In such patients, whether it is safe to become pregnant is controversial. This case illustrates the possibility of carrying a pregnancy to term and providing a vaginal birth if a rigorous preconception consultation is performed to ensure care by a multidisciplinary specialized team, and the patient is properly informed of the risks.

A Young Girl With Bronchiectasis and Elevated Sweat Chloride.

CASE PRESENTATION: A 14-year old girl presented with history of productive cough since the age of 3 years. For the past 6 years, she complained of chest tightness and wheezing. There was also nasal stuffiness and discharge for the past 6 years. She denied history of hemoptysis, ear discharge, or chest pain. There was no history of respiratory distress at the time of birth. Her brother also suffered from productive cough and wheezing since the age of 3 years. However, both her parents were asymptomatic.

Ciliopathies and the Kidney: A Review.

Primary cilia are specialized sensory organelles that protrude from the apical surface of most cell types. During the past 2 decades, they have been found to play important roles in tissue development and signal transduction, with mutations in ciliary-associated proteins resulting in a group of diseases collectively known as ciliopathies. Many of these mutations manifest as renal ciliopathies, characterized by kidney dysfunction resulting from aberrant cilia or ciliary functions. This group of overlapping and genetically heterogeneous diseases includes polycystic kidney disease, nephronophthisis, and Bardet-Biedl syndrome as the main focus of this review. Renal ciliopathies are characterized by the presence of kidney cysts that develop due to uncontrolled epithelial cell proliferation, growth, and polarity, downstream of dysregulated ciliary-dependent signaling. Due to cystic-associated kidney injury and systemic inflammation, cases result in kidney failure requiring dialysis and transplantation. Of the handful of pharmacologic treatments available, none are curative. It is important to determine the molecular mechanisms that underlie the involvement of the primary cilium in cyst initiation, expansion, and progression for the development of novel and efficacious treatments. This review updates research progress in defining key genes and molecules central to ciliogenesis and renal ciliopathies.

Do pulmonary and extrapulmonary features differ among cystic fibrosis, primary ciliary dyskinesia, and healthy children?

BACKGROUND: Primary ciliary dyskinesia (PCD) is generally likened to cystic fibrosis (CF) due to similarities in impaired mucociliary clearance and some other symptoms. The aim of our study was to investigate pulmonary and extrapulmonary characteristics of children with CF and PCD since no studies have addressed respiratory muscle strength in children with PCD and to compare the results to those obtained from healthy age-matched controls. METHODS: Pulmonary and extrapulmonary characteristics were assessed by 6-min walk test, spirometry, maximum inspiratory and expiratory pressure measurements, and knee extensor strength test in the children with CF, PCD, and healthy controls. RESULTS: Children with PCD and CF had similar PFT results, except forced expiratory flow between 25% and 75% of vital capacity (FEF25-75 ) which was lower in PCD (p = .04). Maximum inspiratory pressure (MIP) value was lower in the children with CF compared with the healthy controls (p = .016), MEP value of the children with PCD was worse than those with CF and healthy controls (p = .013 and p = .013), respectively. 6-min walk test (6MWT) distance of the children with CF was lower than their healthy counterparts (p = .003). Knee extensor muscle strength differed among the children with PCD, CF, and healthy control groups, but post hoc test failed to show statistical significance (p = .010). CONCLUSION: Children with CF and PCD had some impairments in pulmonary functions, respiratory muscle strength, functional capacity, and peripheral muscle strength compared with healthy children. However, the unique characteristics of each disease should be considered during physiotherapy assessment and treatment. The clinicians may especially focus on the respiratory and peripheral muscle strength of the children with PCD.

Psychiatric and general health effects of COVID-19 pandemic on children with chronic lung disease and parents' coping styles.

BACKGROUND: We aim to assess the anxiety and depressive symptoms related to the COVID-19 pandemic in children with chronic lung disease and their parents and also to evaluate parents' coping strategies. METHODS: Parents of children aged 4-18 years, with chronic lung disease (study group n = 113) and healthy control (n = 108) were enrolled in the study. General Health Questionnaire-12, specific COVID-19 related anxiety questions, The Coping Orientation to Problems Experienced inventory, coronavirus-related psychiatric symptom scale in children-parental form were used to analyze the psychiatric effects of COVID-19. Parents were also asked about how online education affected their family life and children. All data were compared between children/parents in the study and control groups. Risk factors related with anxiety scores of children were also analyzed. RESULTS: Talking about the pandemic, concern about coronavirus transmission, taking precaution to prevent coronavirus transmission, making pressure to protect from COVID-19 were significantly higher in parents within the study group (p < .05). Parents in the study group used more problem-focused coping than parents in the control group (p = .003). Anxiety symptoms score was higher in children of the study group (p = .007). Parents in the study group found online education more useful than parents in the control group. CONCLUSION: Children with chronic lung diseases and their parents have more anxiety due to COVID-19 pandemic and these parents use more mature coping strategies to manage the stress of the pandemic. Longitudinal and larger studies should be done in all aspects of online education in children with chronic lung diseases.

Comparison of Multiple Breath Washout and Spirometry in Children with Primary Ciliary Dyskinesia and Cystic Fibrosis and Healthy Controls.

Rationale: In cystic fibrosis (CF), the lung clearance index (LCI), derived from multiple breath washout (MBW), is more sensitive in detecting early lung disease than FEV1; MBW has been less thoroughly evaluated in young patients with primary ciliary dyskinesia (PCD).Objectives: Our objectives were 1) to evaluate the sensitivity of MBW and spirometry for the detection of mild lung disease in young children with PCD and CF compared with healthy control (HC) subjects and 2) to compare patterns of airway obstruction between disease populations.Methods: We used a multicenter, single-visit, observational study in children with PCD and CF with a forced expiratory volume in 1 second (FEV1) greater than 60% predicted and HC subjects, ages 3-12 years. Nitrogen MBW and spirometry were performed and overread for acceptability. χ2 and Kruskall-Wallis tests compared demographics and lung function measures between groups, linear regression evaluated the effect of disease state, and Spearman's rank correlation coefficient compared the LCI and spirometric measurements.Results: Twenty-five children with PCD, 49 children with CF, and 80 HC children were enrolled, among whom 17 children with PCD (68%), 36 children with CF (73%), and 53 (66%) HC children performed both acceptable spirometry and MBW; these children made up the analytic cohort. The median age was 9.0 years (interquartile range [IQR], 6.8-11.1). The LCI was abnormal (more than 7.8) in 10 of 17 (59%) patients with PCD and 21 of 36 (58%) patients with CF, whereas FEV1 was abnormal in three of 17 (18%) patients with PCD and six of 36 (17%) patients with CF. The LCI was significantly elevated in patients with PCD and CF compared with HC subjects (ratio of geometric mean vs. HC: PCD 1.27; 95% confidence interval [CI], 1.15-1.39; and CF 1.24; 95% CI, 1.15-1.33]). Children with PCD had lower midexpiratory-phase forced expiratory flow % predicted compared with children with CF (62% [IQR, 50-78%] vs. 85% [IQR, 68-99%]; P = 0.05). LCI did not correlate with FEV1.Conclusions: The LCI is more sensitive than FEV1 in detecting lung disease in young patients with PCD, similar to CF. LCI holds promise as a sensitive endpoint for the assessment of early PCD lung disease.

Clinical features and management of children with primary ciliary dyskinesia in England.

OBJECTIVE: In England, the National Health Service commissioned a National Management Service for children with primary ciliary dyskinesia (PCD). The aims of this study were to describe the health of children seen in this Service and compare lung function to children with cystic fibrosis (CF). DESIGN: Multi-centre service evaluation of the English National Management PCD Service. SETTING: Four nationally commissioned PCD centres in England. PATIENTS: 333 children with PCD reviewed in the Service in 2015; lung function data were also compared with 2970 children with CF. RESULTS: Median age at diagnosis for PCD was 2.6 years, significantly lower in children with situs inversus (1.0 vs 6.0 years, p<0.001). Compared with national data from the CF Registry, mean (SD) %predicted forced expiratory volume in one second (FEV1) was 76.8% in PCD (n=240) and 85.0% in CF, and FEV1 was lower in children with PCD up to the age of 15 years. Approximately half of children had some hearing impairment, with 26% requiring hearing aids. Children with a lower body mass index (BMI) had lower FEV1 (p<0.001). One-third of children had positive respiratory cultures at review, 54% of these grew Haemophilus influenzae. CONCLUSIONS: We provide evidence that children with PCD in England have worse lung function than those with CF. Nutritional status should be considered in PCD management, as those with a lower BMI have significantly lower FEV1. Hearing impairment is common but seems to improve with age. Well-designed and powered randomised controlled trials on management of PCD are needed to inform best clinical practice.

Ventilation Inhomogeneity and Bronchial Basement Membrane Changes in Chronic Neutrophilic Airway Inflammation.

BACKGROUND: Bronchial epithelial reticular basement membrane (RBM) thickening occurs in diseases with both eosinophilic (allergic bronchial asthma [BA]) and neutrophilic (cystic fibrosis [CF] and primary ciliary dyskinesia [PCD]) chronic airway inflammation; however, the lung function and airway remodeling relation remains unclear. The aim of this study was to test whether ventilation inhomogeneity is related to RBM thickening. METHODS: Multiple breath washout test, endobronchial biopsy, and BAL were performed in 24 children with CF, 11 with PCD, 15 with BA, and in 19 control subjects. Lung clearance index at 2.5% (1/40th) of starting nitrogen concentration (LCI2.5), RBM thickness, and lavage fluid cytology were quantified; their mutual associations were studied by using Spearman rank correlations (r). RESULTS: In asthma, ventilation inhomogeneity (mean ± SD) was mild (LCI2.5, 9.3 ± 1.4 vs 7.9 ± 0.9 in control subjects; P = .0391), and the RBM thickened (5.26 ± 0.98 µm vs 3.12 ± 0.62 µm in control subjects; P < .0001). No relation between RBM thickness and ventilation inhomogeneity or lavage cytology was found. In CF and PCD, RBM thickness was similar to that in asthma (4.54 ± 0.66 µm and 5.27 ± 1.11 µm, respectively), but ventilation inhomogeneity was significantly higher (LCI2.5, 12.5 ± 2.4 and 11.8 ± 2.5). Both in CF and PCD, RBM thickness correlated with LCI2.5 (r = 0.594, P = .015; r = 0.821, P = .023). In PCD only, RBM thickness was also related to the number of neutrophils in lavage fluid (r = 0.821; P = .023). CONCLUSIONS: Lung function impairment in relation to RBM thickness was milder in BA than in CF and PCD. In asthma, ventilation inhomogeneity did not correlate with RBM thickness, whereas it did in CF and PCD. This outcome suggests a different structure-function relation in these diseases.

NME5 frameshift variant in Alaskan Malamutes with primary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) is a hereditary defect of motile cilia in humans and several domestic animal species. Typical clinical findings are chronic recurrent infections of the respiratory tract and fertility problems. We analyzed an Alaskan Malamute family, in which two out of six puppies were affected by PCD. The parents were unaffected suggesting autosomal recessive inheritance. Linkage and homozygosity mapping defined critical intervals comprising ~118 Mb. Whole genome sequencing of one case and comparison to 601 control genomes identified a disease associated frameshift variant, c.43delA, in the NME5 gene encoding a sparsely characterized protein associated with ciliary function. Nme5-/- knockout mice exhibit doming of the skull, hydrocephalus and sperm flagellar defects. The genotypes at NME5:c.43delA showed the expected co-segregation with the phenotype in the Alaskan Malamute family. An additional unrelated Alaskan Malamute with PCD and hydrocephalus that became available later in the study was also homozygous mutant at the NME5:c.43delA variant. The mutant allele was not present in more than 1000 control dogs from different breeds. Immunohistochemistry demonstrated absence of the NME5 protein from nasal epithelia of an affected dog. We therefore propose NME5:c.43delA as the most likely candidate causative variant for PCD in Alaskan Malamutes. These findings enable genetic testing to avoid the unintentional breeding of affected dogs in the future. Furthermore, the results of this study identify NME5 as a novel candidate gene for unsolved human PCD and/or hydrocephalus cases.

Developmental and behavioral problems in preschool-aged primary ciliary dyskinesia patients.

Primary ciliary dyskinesia (PCD) causes a broad spectrum of disease. This study aims to explore the developmental, behavioral, and social-emotional aspects of preschool-aged children with PCD. Fourteen PCD, 17 cystic fibrosis (CF) patients and 15 healthy subjects were enrolled. Developmental features of the participants were evaluated with Ages and Stages Questionnaire. Parents of participants filled out the Child Behavior Checklist (CBCL). The number of children screened positive for developmental delay was statistically higher in the PCD group. Higher numbers of children with PCD were screened positive for developmental delay in communication and problem-solving domains. Delay in fine motor skill domain was more common in children with PCD and CF compared to healthy subjects. There was no difference among the three groups in terms of gross motor and personal-social development. None of the children in all three groups was shown to have social-emotional problems. In CBCL, patients with CF had higher internalizing problem scores. Externalizing and total problem scores did not differ between the three groups. However, among PCD patients, children with developmental delay on more than one domain had higher externalizing and total problem scores.Conclusion: The current study revealed that positive screening for developmental delay is more common in preschool-aged PCD patients compared to patients with CF and healthy children. What is Known: • Intelligence scores of school-aged PCD patients are similar to healthy subjects despite their higher internalizing problem scores on Child Behavior Checklist (CBCL). • School-aged PCD patients exhibit higher hyperactivity and inattention findings. What is New: • Positive screening for developmental delay in communication, problem-solving and fine motor skills is more common in preschool-aged PCD patients. • Preschool-aged PCD patients screened positive for developmental delay in more than one domain have higher externalizing and total problem scores on CBCL.

The impact of mannose-binding lectin polymorphisms on lung function in primary ciliary dyskinesia.

OBJECTIVE: Primary ciliary dyskinesia (PCD) is a congenital lung disease that leads to recurrent and chronic lung infection. The resulting inflammation causes lung damage and declines in lung function. Mannose-binding lectin (MBL) is a first line host defense protein of importance for the innate immunity. Polymorphisms in the MBL gene named MBL2 result in unstable and low functional levels MBL proteins. MBL insufficiency is linked to an increased risk of lung infection and to declines in lung function in patients with cystic fibrosis. We investigated whether there is a similar link in patients with PCD. METHODS: This retrospective longitudinal study included 85 patients with PCD. Diagnostics and age at diagnosis were recorded, complete spirometry data starting at diagnosis, and Pseudomonas aeruginosa infection status over the last 2 years were collected, and the patients were grouped according to MBL2 genotype status (MBL2-sufficient or MBL2-deficient). RESULTS: MBL-deficient patients were diagnosed almost 3 years earlier than MBL-sufficient patients (median 6.1 vs 8.9 years, P < 0.05). There were no differences in the first measured spirometry values, but MBL-deficient patients showed greater declines in forced expiratory volume in one sec (FEV1 ) than patients with MBL sufficiency (z-score: -0.049 per year [95% CI, -0.075; -0.021] vs -0.009 per year [95% CI, -0.033; 0.015]; P = 0.023). No differences were found in forced vital capacity (FVC), FEV1 /FVC, or infection status. CONCLUSION: MBL-deficiency, which is associated with MBL2 mutations, was associated with a lower age at diagnosis and with steeper declines in FEV1 in patients with PCD. This suggests that the MBL genotype might be a disease modifier in PCD.

Lack of GAS2L2 Causes PCD by Impairing Cilia Orientation and Mucociliary Clearance.

Primary ciliary dyskinesia (PCD) is a genetic disorder in which impaired ciliary function leads to chronic airway disease. Exome sequencing of a PCD subject identified an apparent homozygous frameshift variant, c.887_890delTAAG (p.Val296Glyfs∗13), in exon 5; this frameshift introduces a stop codon in amino acid 308 of the growth arrest-specific protein 2-like 2 (GAS2L2). Further genetic screening of unrelated PCD subjects identified a second proband with a compound heterozygous variant carrying the identical frameshift variant and a large deletion (c.867_∗343+1207del; p.?) starting in exon 5. Both individuals had clinical features of PCD but normal ciliary axoneme structure. In this research, using human nasal cells, mouse models, and X.laevis embryos, we show that GAS2L2 is abundant at the apical surface of ciliated cells, where it localizes with basal bodies, basal feet, rootlets, and actin filaments. Cultured GAS2L2-deficient nasal epithelial cells from one of the affected individuals showed defects in ciliary orientation and had an asynchronous and hyperkinetic (GAS2L2-deficient = 19.8 Hz versus control = 15.8 Hz) ciliary-beat pattern. These results were recapitulated in Gas2l2-/- mouse tracheal epithelial cell (mTEC) cultures and in X. laevis embryos treated with Gas2l2 morpholinos. In mice, the absence of Gas2l2 caused neonatal death, and the conditional deletion of Gas2l2 impaired mucociliary clearance (MCC) and led to mucus accumulation. These results show that a pathogenic variant in GAS2L2 causes a genetic defect in ciliary orientation and impairs MCC and results in PCD.

A novel, noninvasive assay shows that distal airway oxygen tension is low in cystic fibrosis, but not in primary ciliary dyskinesia.

OBJECTIVES: Oxygen tension affects the biology of aerobic and denitrifying organisms. Using a novel, fast-response sensor, we developed a noninvasive procedure to measure pO2 in distal human airways. We hypothesized that distal pO2 would be low in cystic fibrosis (CF) airways. MATERIALS AND METHODS: We measured the fraction of expired oxygen (FEO2 ) in real time using a fast laser diode analyzer in healthy subjects and in patients with CF, asthma, and primary ciliary dyskinesia (PCD). Subjects slowly exhaled to residual volume (RV), where the nadir of FEO2 (NFO) was recorded. Values were compared to peripheral oxygen saturation (Sa O2 ), expired CO2 at RV, FEV1 , FEV1 /FVC, and FEF25-75 . We also measured the effect of supplemental oxygen on FEO2 . RESULTS: Seventy-four subjects completed the study. Seven additional subjects could not perform the maneuver. Mean (±SD) NFO values for controls (n = 29), CF patients (n = 23), asthma patients (n = 15), and PCD patients (n = 7) were 13.4 ± 1.1%, 12.4 ± 1.2%, 13.3 ± 1.1%, 14.4 ± 0.6%, respectively. NFO in CF was lower than in controls (P = 0.0162), and NFO in PCD was higher than in CF (P = 0.0007). Asthma results were heterogeneous. Oxygen caused a dose-dependent increase in NFO (P < 0.0005; n = 3; r2 = 0.91). NFO values were positively associated with FEV1 (P = 0.0009), FEV1 /FVC (P = 0.0019) and FEF25-75 (P = 0.0155), but there was no association with Sa O2 . CONCLUSIONS: Distal airway pO2 is lower in CF than in controls. This may reflect absorption of oxygen in partially plugged acinar units, and/or increased epithelial oxygen consumption. Distal airway pO2 can be precisely titrated to treat infections.

Translation of the quality-of-life measure for adults with primary ciliary dyskinesia and its application in patients in Brazil / Tradução do questionário de qualidade de vida para pacientes adultos com discinesia ciliar primária no Brasil

ABSTRACT Primary ciliary dyskinesia (PCD) is a genetic disorder that is typically inherited in an autosomal recessive manner. It is clinically characterized by recurrent respiratory infections. However, its repercussions for patient quality of life should not be overlooked. Studies have shown that PCD has a significant impact on the lives of patients, although there are as yet no PCD-specific markers of quality of life. To address that problem, researchers in the United Kingdom developed a quality-of-life questionnaire for patients with PCD. The present communication focuses on the process of translating that questionnaire into Brazilian Portuguese, through a partnership between researchers in Brazil and those in the United Kingdom, as well as its subsequent application in patients in Brazil.

RESUMO A discinesia ciliar primária (DCP) é uma doença genética de origem comumente autossômica recessiva. Caracteriza-se clinicamente por infecções respiratórias de repetição; porém, a repercussão na qualidade de vida desses pacientes deve ser levada em consideração. Estudos têm demonstrado um importante impacto da doença nesse quesito, mas ainda faltam marcadores de qualidade de vida específicos para DCP. Nesse sentido, foi desenvolvido o questionário de qualidade de vida em pacientes com DCP. O presente comunicado versa sobre o processo de tradução do questionário desenvolvido no Reino Unido para o português falado no Brasil através de uma parceria entre pesquisadores do Brasil e Reino Unido e sua posterior aplicação a pacientes brasileiros.

Lung function in patients with primary ciliary dyskinesia: an iPCD Cohort study.

Primary ciliary dyskinesia (PCD) has been considered a relatively mild disease, especially compared to cystic fibrosis (CF), but studies on lung function in PCD patients have been few and small.This study compared lung function from spirometry of PCD patients to normal reference values and to published data from CF patients. We calculated z-scores and % predicted values for forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) using the Global Lung Function Initiative 2012 values for 991 patients from the international PCD Cohort. We then assessed associations with age, sex, country, diagnostic certainty, organ laterality, body mass index and age at diagnosis in linear regression models. Lung function in PCD patients was reduced compared to reference values in both sexes and all age groups. Children aged 6-9 years had the smallest impairment (FEV1 z-score -0.84 (-1.03 to -0.65), FVC z-score -0.31 (-0.51 to -0.11)). Compared to CF patients, FEV1 was similarly reduced in children (age 6-9 years PCD 91% (88-93%); CF 90% (88-91%)), but less impaired in young adults (age 18-21 years PCD 79% (76-82%); CF 66% (65-68%)). The results suggest that PCD affects lung function from early in life, which emphasises the importance of early standardised care for all patients.

Motile Ciliary Disorders in Chronic Airway Inflammatory Diseases: Critical Target for Interventions.

PURPOSE OF REVIEW: Impaired mucociliary clearance has been implicated in chronic upper and lower airway inflammatory diseases (i.e., allergic and non-allergic rhinitis, chronic rhinosinusitis with or without nasal polyps and asthma). How motile ciliary disorders (impaired ciliogenesis, ciliary beating and ultrastructural defects) are implicated in chronic airway inflammatory diseases is not fully understood. Elaboration of the role of motile ciliary disorders may serve as therapeutic targets for improving mucociliary clearance, thereby complementing contemporary disease management. RECENT FINDINGS: We have summarized the manifestations of motile ciliary disorders and addressed the underlying associations with chronic airway inflammatory diseases. A panel of established and novel diagnostic tests and therapeutic interventions are outlined. Physicians should be vigilant in screening for motile ciliary disorders, particularly in patients with co-existing upper and lower airway inflammatory diseases. Proper assessment and treatment of motile ciliary disorders may have added value to the management and prevention of chronic airway inflammatory diseases.

Fitness and lung function in children with primary ciliary dyskinesia and cystic fibrosis.

BACKGROUND: Peak oxygen uptake (VO2peak) is associated with morbidity and mortality in health and disease, and provides important information of global physical health not achieved from standard pulmonary function tests. Primary ciliary dyskinesia (PCD) and cystic fibrosis (CF) are genetically determined diseases involving different basic defects, but both showing impaired mucociliary clearance leading to chronic infections and pulmonary destruction early in life. PCD is generally considered a milder disease than CF and it is hypothesized that children with CF would have consistently lower VO2peak and pulmonary function than children with PCD. METHODS: We performed a prospective, observational single-center, clinical cohort study of VO2peak and pulmonary function in age and gender matched schoolchildren, at two occasions 12 months apart. RESULTS: VO2peak was persistently (at baseline and after 12 months) and significantly reduced in the 22 patients with PCD (z-score = -0.89 and -1.0) and 24 with CF (z-score = -0.94 and -1.1), included in the study. Abnormal VO2peak was detected in a larger proportion of children with PCD (≈30%) than CF (≈13%). Moreover, children with PCD exhibited persistently lower FEV1 (p < 0.0001 at first visit and p = 0.001 at second visit) while FEF25-75 and FVC differed only at baseline. Indeed, a retrospective analysis comparing lung function over the last year in our entire PCD and CF populations between 6 and 18 years of age, revealed lower values in patients with PCD (FEV1 z-score, p = 0.0004, FVC z-score p < 0.0001, FEF25-75 z-score p = 0.008). CONCLUSION: This is the first report indicating that cardiopulmonary fitness is equally and consistently reduced in both children with PCD and CF along with a consistent lower pulmonary function in PCD compared with CF. A certain reservation for possible selection bias and the small number of patients is necessary. However, increased focus on early diagnosis, evidence-based treatment regimens and close clinical monitoring in PCD are warranted.

Pathophysiology and Genetics of Bronchiectasis Unrelated to Cystic Fibrosis.

Bronchiectasis is characterized by deregulated inflammatory response and recurrent bacterial infection resulting in progressive lung damage and an irreversible dilatation of bronchi and bronchioles. Generally accepted model of the development of bronchiectasis is the "vicious cycle hypothesis" that proposes compromising of the mucociliary clearance by an initial event, which leads to the infection of the respiratory tract followed by further impairment of mucociliary function, bacterial proliferation, and more inflammation. Bronchiectasis is a very common symptom in patients with cystic fibrosis (CF), while bronchiectasis unrelated to CF is heterogeneous pathology of unknown cause with a large number of potential contributory factors and poorly understood pathogenesis. It is presumed that bronchiectasis unrelated to CF is a multifactorial condition predisposed by genetic factors. Different molecules have been implicated in the onset and development of idiopathic bronchiectasis, as well as modulation of the disease severity and response to therapy. Most of these molecules are involved in the processes that contribute to the homeostasis of the lung tissue, especially mucociliary clearance, protease-antiprotease balance, and immunomodulation. Evaluation of the studies performed towards investigation of the role these molecules play in bronchiectasis identifies genetic variants that may be of potential importance for clinical management of the disease, and also of interest for future research efforts. This review focuses on the molecules with major roles in lung homeostasis and their involvement in bronchiectasis unrelated to CF.