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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., (© 2024 Wiley Periodicals LLC.)

Electronic cigarettes are driving a new epidemic of nicotine dependence among youths and are now the dominant tobacco product used by adolescents in the United States and other countries. Candy and fruit flavorings have driven their use, and many products contain higher nicotine concentrations, which contributed to their addictive potential. Numerous epidemiologic studies have described increased rates of respiratory symptoms in adolescent electronic cigarette users, and in vitro and in vivo studies showed that electronic cigarette vapors exert extensive biological effects on human airways, different from tobacco smoke, leading to epithelial cell dysregulation, inflammation, mucus hypersecretion, and apoptosis. Severe acute lung injury has been reported in adolescents and young adults, particularly in those using tetrahydrocannabinol (THC)-containing products, underscoring the threats of electronic cigarettes to lung health., (© 2024 Wiley Periodicals LLC.)

Background: With more than 103 million cases and 1.1 million deaths, the COVID-19 pandemic has had devastating consequences for the health system and the well-being of the entire US population. The Rare Diseases Clinical Research Network funded by the National Institutes of Health was strategically positioned to study the impact of the pandemic on the large, vulnerable population of people living with rare diseases (RDs)., Objective: This study was designed to describe the characteristics of COVID-19 in the RD population, determine whether patient subgroups experienced increased occurrence or severity of infection and whether the pandemic changed RD symptoms and treatment, and understand the broader impact on respondents and their families., Methods: US residents who had an RD and were <90 years old completed a web-based survey investigating self-reported COVID-19 infection, pandemic-related changes in RD symptoms and medications, access to care, and psychological impact on self and family. We estimated the incidence of self-reported COVID-19 and compared it with that in the US population; evaluated the frequency of COVID-19 symptoms according to self-reported infection; assessed infection duration, complications and need for hospitalization; assessed the influence of the COVID-19 pandemic on RD symptoms and treatment, and whether the pandemic influenced access to care, special food and nutrition, or demand for professional psychological assistance., Results: Between May 2, 2020, and December 15, 2020, in total, 3413 individuals completed the survey. Most were female (2212/3413, 64.81%), White (3038/3413, 89.01%), and aged ≥25 years (2646/3413, 77.53%). Overall, 80.6% (2751/3413) did not acquire COVID-19, 2.08% (71/3413) acquired it, and 16.58% (566/3413) did not know. Self-reported cases represented an annual incidence rate of 2.2% (95% CI 1.7%-2.8%). COVID-19 cases were more than twice the expected (71 vs 30.3; P<.001). COVID-19 was associated with specific symptoms (loss of taste: odds ratio [OR] 38.9, 95% CI 22.4-67.6, loss of smell: OR 30.6, 95% CI 17.7-53.1) and multiple symptoms (>9 symptoms vs none: OR 82.5, 95% CI 29-234 and 5-9: OR 44.8, 95% CI 18.7-107). Median symptom duration was 16 (IQR 9-30) days. Hospitalization (7/71, 10%) and ventilator support (4/71, 6%) were uncommon. Respondents who acquired COVID-19 reported increased occurrence and severity of RD symptoms and use or dosage of select medications; those who did not acquire COVID-19 reported decreased occurrence and severity of RD symptoms and use of medications; those who did not know had an intermediate pattern. The pandemic made it difficult to access care, receive treatment, get hospitalized, and caused mood changes for respondents and their families., Conclusions: Self-reported COVID-19 was more frequent than expected and was associated with increased prevalence and severity of RD symptoms and greater use of medications. The pandemic negatively affected access to care and caused mood changes in the respondents and family members. Continued surveillance is necessary., (©Maurizio Macaluso, Marc E Rothenberg, Thomas Ferkol, Pierce Kuhnell, Henry J Kaminski, David W Kimberlin, Michael Benatar, Mirna Chehade, The Principal Investigators of the Rare Diseases Clinical Research Network – Cycle 4. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 14.02.2024.)

Background: In cystic fibrosis (CF), pathophysiologic changes in the gastrointestinal tract lead to malnutrition and altered gut microbiome. Microbiome alterations have been linked to linear growth, gut inflammation and respiratory manifestations. Elucidating these gut microbiome alterations may provide insight into future nutritional management in CF., Methods: Infants were followed for 12-months at four sites in the United States (US-CF) and Australia (AUS-CF). 16S rRNA gene sequencing was performed on longitudinal stool samples. Associations between microbial abundance and age, antibiotic prophylaxis, malnutrition, and breast feeding were evaluated using generalized linear mixed models. Taxonomic and predictive functional features were compared between groups., Results: Infants with CF (N = 78) were enrolled as part of a larger study. AUS-CF infants had higher mean weight-for-age z-scores than US-CF infants (p = 0.02). A subset of participants (CF N = 40, non-CF disease controls N = 10) provided stool samples for microbiome analysis. AUS-CF infants had lower stool alpha diversity compared to US-CF infants (p < 0.001). AUS-CF infants had higher relative abundance of stool Proteobacteria compared to US-CF infants which was associated with antibiotic prophylaxis (p < 0.001). Malnutrition (weight-for-age <10th percentile) was associated with depleted Lactococcus (p < 0.001). Antibiotic prophylaxis (p = 0.002) and malnutrition (p = 0.012) were linked with predicted decreased activity of metabolic pathways responsible for short chain fatty acid processing., Conclusions: In infants with CF, gut microbiome composition and diversity differed between the two continents. Gut microbial diversity was not linked to growth. The relationship between malnutrition and antibiotic prophylaxis with reduced SCFA fermentation could have implications for gut health and function and warrants additional investigation., Competing Interests: Declaration of Competing Interest S. Davis served on the Vertex advisory board, (Copyright © 2023. Published by Elsevier B.V.)

Nasal nitric oxide (nNO) is extremely low in most people with primary ciliary dyskinesia (PCD) and its measurement is an important contributor to making the diagnosis. Existing guidelines and technical standards focus on nNO measurements in older, cooperative children using chemiluminescence analysers. However, measurements of nNO in pre-school-age children (age 2-5 years) may facilitate early diagnosis and electrochemical rather than chemiluminescence analysers are widely used. Pre-schoolers often need different methods to be employed when measuring nNO. Hence, a European Respiratory Society Task Force has developed this technical standard as the first step towards standardising sampling, analysis and reporting of nNO measured as part of the diagnostic testing for PCD in all age groups, including pre-school-age children. Furthermore, we considered both chemiluminescence and electrochemical analysers that are in use worldwide. There was a paucity of quality evidence for electrochemical analysers and sampling methods used in young children, and the Task Force proposes future research priorities to allow updates of this technical standard., Competing Interests: Conflict of interest: N. Beydon reports educational writing payments as a member of the HERMES examination committee for paediatric respiratory medicine of the European Respiratory Society, and a leadership role as Chair of Group 07.01 of the European Respiratory Society (Paediatric respiratory physiology and sleep), outside the submitted work. P. Latzin reports grants from Vertex and OM Pharma, lecture honoraria from Vertex, Vifor and OM Pharma, and advisory board participation from Polyphor, Santhera (DMC), Vertex, Vifor, OM Pharma and Sanofi Aventis, outside the submitted work. S.D. Davis reports grants from the National Institutes of Health/National Heart, Lung, and Blood Institute, to support the present manuscript, and consulting fees from Parion Sciences and ReCode Therapeutics, and advisory board participation for the PCD Foundation, outside the submitted work. T. Ferkol reports grants from the National Institutes of Health (HL096458) to support the present manuscript, and grants from the National Institutes of Health (HL116211, HL125241, AI146999), National Health and Medical Research Council (NHMRC1043768) and Parion Sciences, advisory board participation for the PCD Foundation, Parion Sciences and Translate Bio, and is past president and executive board member of the American Thoracic Society, outside the submitted work. J.S. Lucas reports grants from AAIR Charity and NIHR Research for patient benefit, and consulting fees from Translate Bio, outside the submitted work. All other authors have nothing to disclose., (Copyright ©The authors 2023. For reproduction rights and permissions contact permissions@ersnet.org.)

Nasal nitric oxide (nNO) measurements are used in the assessment of patients suspected of having primary ciliary dyskinesia (PCD), but recommendations for performing such measurements have not focused on children and do not include all current practices. To guide the development of a European Respiratory Society-supported technical standard for nNO measurement in children, an international online survey was conducted to better understand current measurement practices among providers involved in PCD diagnostics. 78 professionals responded, representing 65 centres across 18 countries, mainly in Europe and North America. Nearly all centres measured nNO in children and more than half performed measurements before 5 years of age. The test was often postponed in children with signs of acute airway infection. In Europe, the electrochemical technique was more frequently used than chemiluminescence. A similar proportion of centres performed measurements during exhalation against a resistance (49 out of 65) or during tidal breathing (50 out of 65); 15 centres used only exhalation against a resistance and 15 used only tidal breathing. The cut-off values used to discriminate PCD were consistent across centres using chemiluminescence analysers; these centres reported results as an output (nL·min -1 ). Cut-off values were highly variable across centres using electrochemical devices, and nNO concentrations were typically reported as ppb. This survey is the first to determine real-world use of nNO measurements globally and revealed remarkable variability in methodology, equipment and interpretation. These findings will help standardise methods and training., Competing Interests: Conflict of interest: N. Beydon declares no competing interests. Conflict of interest: T. Ferkol declares no competing interests. Conflict of interest: A.L. Harris declares no competing interests. Conflict of interest: M. Colas declares no competing interests. Conflict of interest: S.D. Davis declares grant NIH U54 HL09640958 funded by the Office of Rare Diseases Research (NCATS) in the 36 months prior to manuscript submission, and membership of the PCD Foundation Medical and Scientific Advisory Council. Conflict of interest: E. Haarman declares no competing interests. Conflict of interest: C. Hogg declares no competing interests. Conflict of interest: E. Kilbride declares no competing interests. Conflict of interest: P. Kouis declares no competing interests. Conflict of interest: C.E. Kuehni declares no competing interests. Conflict of interest: P. Latzin declares grants to their institution from Vertex and Vifor; payment to their institution and themself for lectures, presentations, speaker bureaus, manuscript writing or educational events from Vertex, Vifor and OM Pharma; and paid (to their institution and/or themself) participation on data safety monitoring or advisory boards for Polyphor, Santhera (DMC), Vertex, OM Pharma, Vifor and Sanofi Aventis, all in the 36 months prior to manuscript submission. Conflict of interest: D. Marangu declares no competing interests. Conflict of interest: J. Marthin declares no competing interests. Conflict of interest: K.G. Nielsen declares no competing interests. Conflict of interest: P. Robinson declares no competing interests. Conflict of interest: N. Rumman declares no competing interests. Conflict of interest: M. Rutter declares no competing interests. Conflict of interest: W. Walker declares no competing interests. Conflict of interest: J.S. Lucas declares no competing interests., (Copyright ©The authors 2022.)

Background: Primary ciliary dyskinesia (PCD) is a rare genetic disease arising from motile ciliary dysfunction and associated with recurrent and chronic upper and lower respiratory tract infections. Pediatric otolaryngologists may see these patients prior to the development of lung disease. Features of PCD may overlap with other suppurative respiratory diseases, creating diagnostic challenges. A simple screening tool would be beneficial to identify potential patients who have chronic upper respiratory tract disease requiring further specialist evaluation., Objective: To test a simple screening tool consisting of four questions to detect PCD in children with chronic otitis media and chronic rhinosinusitis seen in a tertiary otolaryngology clinic., Methods: A prospective, single site, observational study in a tertiary care pediatric otolaryngology clinic. Children aged 3-17 years diagnosed with chronic otitis media or rhinosinusitis with onset at less than 2 years of age were recruited. All study subjects had at least one of four key clinical features for PCD as determined by answers to screening questions, while control subjects had none. All participants completed a medical history questionnaire and nasal nitric oxide measurements. Those with reduced nasal nitric oxide levels were referred to our PCD center for further evaluation., Results: A total of 153 patients were screened and 62 subjects were enrolled. Of those, 35 were enrolled as study subjects and 27 as matched controls. Study subjects had mean age of 7.5 years (3.2-16.5) with pre-screening diagnosis of chronic otitis media (n = 29) or chronic rhinosinusitis (n = 6). Control subjects (n = 27) had mean age 7.2 years (3.0-16.3) with pre-screening diagnosis of chronic otitis media (n = 25), and chronic rhinosinusitis (n = 2). There were no differences in subject demographics or mean nasal nitric oxide values between the two groups (179.8 vs 210.8 nl/min). Ten individuals had low nasal nitric oxide values, 7 of which were normal on repeat testing. Three subjects failed to return for follow up evaluations. Four referrals were made for further evaluation on the basis of clinical symptoms and nasal nitric oxide results. While no new cases of PCD were detected, a subject and his sibling with recurrent sinopulmonary infections were referred for immunologic evaluation., Conclusion: The use of standardized screening questions can be used in an otolaryngology clinic to identify patients who require further evaluation for PCD or primary immunodeficiency., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Tobacco has long been known to be one of the greatest causes of morbidity and mortality in the adults, but the effects on the foetus and young children, which are lifelong, have been less well appreciated. Developing from this are electronic nicotine delivery systems or vapes, promulgated as being less harmful than tobacco. Nicotine itself is toxic to the foetus, with permanent effects on lung structure and function. Most vapes contain nicotine, but they also contain many other compounds which are inhaled and for which there are no toxicity studies. They also contain known toxic substances, whose use is banned by European Union legislation. Accelerating numbers of young people are vaping, and this does not reflect an exchange of vapes for cigarettes. The acute toxicity of e-cigarettes is greater than that of tobacco, and includes acute lung injury, pulmonary haemorrhage and eosinophilic and lipoid pneumonia. Given the worse acute toxicity, it should be impossible to be complacent about medium and long term effects of vaping. Laboratory studies have demonstrated changes in lung proteomics and the innate immune system with vaping, some but not all of which overlap with tobacco. It would be wrong to consider vapes as a weaker form of tobacco, they have their own toxicity. Children and young people are being targeted by the vaping industry (which is largely the same as the tobacco industry), including on-line, and unless an efficient legislative program is put in place, a whole new generation of nicotine addicts will result., (Copyright © 2021 Andrew Bush, Thomas Ferkol, Algirdas Valiulis, Artur Mazur, Ivane Chkhaidze, Tamaz Maglakelidze, Sergey Sargsyan, Gevorg Boyajyan, Olga Cirstea, Svitlana Doan, Oleksandr Katilov, Valeriy Pokhylko, Leonid Dubey, Edita Poluziorovienė, Nina Prokopčiuk, Vaida Taminskienė, Arūnas Valiulis.)

Hydrocephalus is one of the most prevalent form of developmental central nervous system (CNS) malformations. Cerebrospinal fluid (CSF) flow depends on both heartbeat and body movement. Furthermore, it has been shown that CSF flow within and across brain ventricles depends on cilia motility of the ependymal cells lining the brain ventricles, which play a crucial role to maintain patency of the narrow sites of CSF passage during brain formation in mice. Using whole-exome and whole-genome sequencing, we identified an autosomal-dominant cause of a distinct motile ciliopathy related to defective ciliogenesis of the ependymal cilia in six individuals. Heterozygous de novo mutations in FOXJ1, which encodes a well-known member of the forkhead transcription factors important for ciliogenesis of motile cilia, cause a motile ciliopathy that is characterized by hydrocephalus internus, chronic destructive airway disease, and randomization of left/right body asymmetry. Mutant respiratory epithelial cells are unable to generate a fluid flow and exhibit a reduced number of cilia per cell, as documented by high-speed video microscopy (HVMA), transmission electron microscopy (TEM), and immunofluorescence analysis (IF). TEM and IF demonstrate mislocalized basal bodies. In line with this finding, the focal adhesion protein PTK2 displays aberrant localization in the cytoplasm of the mutant respiratory epithelial cells., (Copyright © 2019 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Background: Biallelic deleterious variants in RTTN, which encodes rotatin, are associated with primary microcephaly, polymicrogyria, seizures, intellectual disability, and primordial dwarfism in human infants., Methods and Results: We performed exome sequencing of an infant with primary microcephaly, pontocerebellar hypoplasia, and intractable seizures and his healthy, unrelated parents. We cultured the infant's fibroblasts to determine primary ciliary phenotype., Results: We identified biallelic variants in RTTN in the affected infant: a novel missense variant and a rare, intronic variant that results in aberrant transcript splicing. Cultured fibroblasts from the infant demonstrated reduced length and number of primary cilia., Conclusion: Biallelic variants in RTTN cause primary microcephaly in infants. Functional characterization of primary cilia length and number can be used to determine pathogenicity of RTTN variants.

Chronic respiratory disease can affect growth and nutrition, which can influence lung function. We investigated height, body mass index (BMI), and lung function in patients with primary ciliary dyskinesia (PCD).In this study, based on the international PCD (iPCD) Cohort, we calculated z-scores for height and BMI using World Health Organization (WHO) and national growth references, and assessed associations with age, sex, country, diagnostic certainty, age at diagnosis, organ laterality and lung function in multilevel regression models that accounted for repeated measurements.We analysed 6402 measurements from 1609 iPCD Cohort patients. Height was reduced compared to WHO (z-score -0.12, 95% CI -0.17 to -0.06) and national references (z-score -0.27, 95% CI -0.33 to -0.21) in male and female patients in all age groups, with variation between countries. Height and BMI were higher in patients diagnosed earlier in life (p=0.026 and p<0.001, respectively) and closely associated with forced expiratory volume in 1 s and forced vital capacity z-scores (p<0.001).Our study indicates that both growth and nutrition are affected adversely in PCD patients from early life and are both strongly associated with lung function. If supported by longitudinal studies, these findings suggest that early diagnosis with multidisciplinary management and nutritional advice could improve growth and delay disease progression and lung function impairment in PCD., Competing Interests: Conflict of interest: Disclosures can be found alongside this article at erj.ersjournals.com, (Copyright ©ERS 2017.)

Primary ciliary dyskinesia is an inherited disease characterized by impaired ciliary function leading to diverse clinical manifestations, including chronic sinopulmonary disease, persistent middle ear effusions, laterality defects, and infertility. Our understanding of the complex genetics and functional phenotypes of primary ciliary dyskinesia has rapidly grown, and over 35 disease-associated genes have been identified, which segregate into genes that encode axonemal motor proteins, regulatory proteins within the cilium, and cytoplasmic proteins involved in ciliary assembly. These findings have yielded unexpected insights into the clinical heterogeneity of disease and are beginning to revolutionize diagnostic testing for primary ciliary dyskinesia., (Copyright © 2017. Published by Elsevier Ltd.)

Objective: To assess the utility of clinical predictors of persistent respiratory morbidity in extremely low gestational age newborns (ELGANs)., Study Design: We enrolled ELGANs (<29 weeks' gestation) at ≤7 postnatal days and collected antenatal and neonatal clinical data through 36 weeks' postmenstrual age. We surveyed caregivers at 3, 6, 9, and 12 months' corrected age to identify postdischarge respiratory morbidity, defined as hospitalization, home support (oxygen, tracheostomy, ventilation), medications, or symptoms (cough/wheeze). Infants were classified as having postprematurity respiratory disease (PRD, the primary study outcome) if respiratory morbidity persisted over ≥2 questionnaires. Infants were classified with severe respiratory morbidity if there were multiple hospitalizations, exposure to systemic steroids or pulmonary vasodilators, home oxygen after 3 months or mechanical ventilation, or symptoms despite inhaled corticosteroids. Mixed-effects models generated with data available at 1 day (perinatal) and 36 weeks' postmenstrual age were assessed for predictive accuracy., Results: Of 724 infants (918 ± 234 g, 26.7 ± 1.4 weeks' gestational age) classified for the primary outcome, 68.6% had PRD; 245 of 704 (34.8%) were classified as severe. Male sex, intrauterine growth restriction, maternal smoking, race/ethnicity, intubation at birth, and public insurance were retained in perinatal and 36-week models for both PRD and respiratory morbidity severity. The perinatal model accurately predicted PRD (c-statistic 0.858). Neither the 36-week model nor the addition of bronchopulmonary dysplasia to the perinatal model improved accuracy (0.856, 0.860); c-statistic for BPD alone was 0.907., Conclusion: Both bronchopulmonary dysplasia and perinatal clinical data accurately identify ELGANs at risk for persistent and severe respiratory morbidity at 1 year., Trial Registration: ClinicalTrials.gov: NCT01435187., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Recovering premature infants are at risk for hypoxemia and lack of synchrony between their rib cage and abdomen due to airflow obstruction and poor respiratory compliance. Thoracoabdominal asynchrony (TAA) is a useful marker of resistive and elastic lung properties. Whether TAA predicts oxygenation is unknown., Objectives: We investigated oxyhemoglobin saturation (SpO2%) and TAA (phase angle, φ) in preterm infants with/without high-humidity nasal cannula (HHNC)., Methods: A cross-sectional observational study was conducted in 92 infants at 32 weeks' postmenstrual age. We measured SpO2% with pulse oximetry and TAA with φ via respiratory inductance plethysmography in infants (mean gestational age: 26.4 + 1.3 weeks) who required room air (n = 18) or HHNC with/without supplemental oxygen (1-5 liters per minute, FiO2 0.21-0.33, n = 74). We calculated median SpO2% from 24.7 + 10.0 min of quiet sleep and median φ from up to 60 breaths., Results: Infants breathing room air alone had marked TAA (φ = 83.6 + 32.9°, range: 10.9-148.5) as did those receiving varying degrees of ventilatory and oxygen support via HHNC (range of group means, φ = 47.0-90.0°). Infants breathing room air had statically greater median SpO2% than those receiving support (96.3 + 0.6% vs. 91.3 + 0.6%; ANOVA p = 0.001). SpO2% was not associated with TAA in either group (r2 = 0.09)., Conclusion: Recovering premature infants exhibited TAA regardless of need for ventilatory support and supplemental oxygen. TAA was not associated with SpO2% in either group. Maintenance of SpO2% does not require correction of TAA., (© 2016 S. Karger AG, Basel.)

Background: Children with chronic invasive ventilator dependence living at home are a diverse group of children with special health care needs. Medical oversight, equipment management, and community resources vary widely. There are no clinical practice guidelines available to health care professionals for the safe hospital discharge and home management of these complex children., Purpose: To develop evidence-based clinical practice guidelines for the hospital discharge and home/community management of children requiring chronic invasive ventilation., Methods: The Pediatric Assembly of the American Thoracic Society assembled an interdisciplinary workgroup with expertise in the care of children requiring chronic invasive ventilation. The experts developed four questions of clinical importance and used an evidence-based strategy to identify relevant medical evidence. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used to formulate and grade recommendations., Results: Clinical practice recommendations for the management of children with chronic ventilator dependence at home are provided, and the evidence supporting each recommendation is discussed., Conclusions: Collaborative generalist and subspecialist comanagement is the Medical Home model most likely to be successful for the care of children requiring chronic invasive ventilation. Standardized hospital discharge criteria are suggested. An awake, trained caregiver should be present at all times, and at least two family caregivers should be trained specifically for the child's care. Standardized equipment for monitoring, emergency preparedness, and airway clearance are outlined. The recommendations presented are based on the current evidence and expert opinion and will require an update as new evidence and/or technologies become available.

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous, rare lung disease resulting in chronic oto-sino-pulmonary disease in both children and adults. Many physicians incorrectly diagnose PCD or eliminate PCD from their differential diagnosis due to inexperience with diagnostic testing methods. Thus far, all therapies used for PCD are unproven through large clinical trials. This review article outlines consensus recommendations from PCD physicians in North America who have been engaged in a PCD centered research consortium for the last 10 years. These recommendations have been adopted by the governing board of the PCD Foundation to provide guidance for PCD clinical centers for diagnostic testing, monitoring, and appropriate short and long-term therapeutics in PCD patients., (© 2015 The Authors. Pediatric Pulmonology Published by Wiley Periodicals, Inc.)

Rationale: Methicillin-resistant Staphylococcus aureus (MRSA) prevalence continues to increase in patients with cystic fibrosis (CF) in the United States, reaching 26.5% in 2012. Approximately 30% of strains are SCCmec (staphylococcal cassette chromosome mec) IV type, frequently USA300, which in the general population have different genotypic and phenotypic features than SCCmec II type., Objectives: We hypothesized that risk factors for acquisition and outcomes in patients with CF differed for "health care-associated" (SCCmec II) versus "community-associated" (SCCmec IV) MRSA strains., Methods: To determine the role of SCCmec type and Panton-Valentine leukocidin (PVL), MRSA isolates from patients not more than 18 years old at seven CF centers were typed and the association of potential risk factors and subsequent clinical course was assessed, using data provided by the CF Patient Registry., Measurements and Main Results: Participants with chronic MRSA (295) had typeable isolates and clinical data; 205 (69.5%) had SCCmec II PVL(-), 39 (13.2%) had SCCmec IV PVL(-), and 51 (17.3%) had SCCmec IV PVL(+) strains. SCCmec IV, compared with SCCmec II, increased during the study period, 1996-2010 (P = 0.03). SCCmec II was associated with Pseudomonas aeruginosa-positive cultures and three or more clinic visits in the 6 months preceding the first positive MRSA culture (adjusted odds ratio, 2.05; 95% confidence interval, 1.13-3.74; P = 0.019). Lung function and anthropometrics remained unchanged in the 6 months after initial MRSA detection compared with the 6 months prior. Although CF care increased for participants in both groups in the 6 months after MRSA detection, inhaled antibiotics were prescribed more frequently in those with SCCmec II strains and increased hospitalizations occurred in those with SCCmec IV PVL(-) strains compared with those with PVL(+) strains (adjusted difference, 34.10%; 95% confidence interval, 7.58-60.61; P = 0.012). Participants in both groups had an increase in CF care in the 2 years after MRSA detection compared with the 2 years prior., Conclusions: Increased exposure to CF clinics and P. aeruginosa may constitute risk factors for acquisition of SCCmec II MRSA strains. Clinical interventions increased 6 months and 2 years after initial MRSA detection regardless of SCCmec type.

Objectives: Our goal was to evaluate changes in respiratory pattern among premature infants born at <29 weeks gestation who underwent a physiological challenge at 36 weeks postmenstrual age with systematic reductions in supplemental oxygen and inspired airflow., Study Design: Subjects were all infants enrolled in the Prematurity and Respiratory Outcomes Project at St. Louis Children's Hospital and eligible for a physiological challenge protocol because they were receiving supplemental oxygen or augmented airflow alone as part of their routine care. Continuous recording of rib cage and abdominal excursion and haemoglobin oxygen saturation (SpO2%) were made in the newborn intensive care unit., Results: 37 of 49 infants (75.5%) failed the challenge, with severe or sustained falls in SpO2%. Also, 16 of 37 infants (43.2%) who failed had marked increases in the amount of periodic breathing at the time of challenge failure., Conclusions: An unstable respiratory pattern is unmasked with a decrease in inspired oxygen or airflow support in many premature infants. Although infants with significant chronic lung disease may also be predisposed to more periodic breathing, these data suggest that the classification of chronic lung disease of prematurity based solely on clinical requirements for supplemental oxygen or airflow do not account for multiple mechanisms that are likely contributing to the need for respiratory support., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: Bronchiolitis obliterans (BO) is the leading cause of mortality beyond the first year after pediatric lung transplant, but the performance of an open lung biopsy is often required for diagnosis. Bronchiolitis obliterans syndrome (BOS) is a clinical diagnosis based on spirometric data that is the accepted standard for staging chronic allograft dysfunction., Methods: We determined the sensitivity, specificity, and positive and negative predictive values of BOS for predicting BO in children. A chart review was conducted on 139 open lung biopsies and 43 lung explants performed at our center from 1990 through June 2010 in pediatric recipients of lung transplants. Results were excluded from analysis if insufficient data existed to calculate a stable BOS stage before biopsy/explant., Results: The criteria for inclusion in the study were met by 67 open lung biopsies and 31 lung explants. The sensitivity, specificity, positive predictive value, and negative predictive value of BOS for predicting BO were 91.0%, 25.8%, 72.6%, and 57.1%., Conclusions: We found that early declines in lung function are sensitive, but not specific, for BO. The low specificity of BOS for identifying BO illustrates the challenge facing clinicians in determining the etiology of pulmonary decline after lung transplant., (Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Background: Motile cilia dysfunction causes primary ciliary dyskinesia (PCD), situs inversus totalis (SI), and a spectrum of laterality defects, yet the prevalence of laterality defects other than SI in PCD has not been prospectively studied., Methods: In this prospective study, participants with suspected PCD were referred to our multisite consortium. We measured nasal nitric oxide (nNO) level, examined cilia with electron microscopy, and analyzed PCD-causing gene mutations. Situs was classified as (1) situs solitus (SS), (2) SI, or (3) situs ambiguus (SA), including heterotaxy. Participants with hallmark electron microscopic defects, biallelic gene mutations, or both were considered to have classic PCD., Results: Of 767 participants (median age, 8.1 years, range, 0.1-58 years), classic PCD was defined in 305, including 143 (46.9%), 125 (41.0%), and 37 (12.1%) with SS, SI, and SA, respectively. A spectrum of laterality defects was identified with classic PCD, including 2.6% and 2.3% with SA plus complex or simple cardiac defects, respectively; 4.6% with SA but no cardiac defect; and 2.6% with an isolated possible laterality defect. Participants with SA and classic PCD had a higher prevalence of PCD-associated respiratory symptoms vs SA control participants (year-round wet cough, P < .001; year-round nasal congestion, P = .015; neonatal respiratory distress, P = .009; digital clubbing, P = .021) and lower nNO levels (median, 12 nL/min vs 252 nL/min; P < .001)., Conclusions: At least 12.1% of patients with classic PCD have SA and laterality defects ranging from classic heterotaxy to subtle laterality defects. Specific clinical features of PCD and low nNO levels help to identify PCD in patients with laterality defects., Trial Registry: ClinicalTrials.gov; No.: NCT00323167; URL: www.clinicaltrials.gov.

Cystic fibrosis (CF) is a life-limiting, monogenic disorder characterized by chronic sinopulmonary and gastrointestinal involvement. Progressive pulmonary disease leads to death in the majority of patients. Despite its well-defined molecular basis related to defects in the cystic fibrosis transmembrane conductance regulator anion transport channel, there are large gaps in our understanding of the origin of CF lung disease. Disease has been shown to be present in infancy, and there is mounting evidence that abnormalities begin in utero. Heterogeneity of clinical presentations and severity suggest that many factors involved in lung disease have yet to be fully elucidated. Although new advances in therapeutic treatments have shown promise in delaying disease progression, the prevention of pulmonary disease at its origin (primary prevention) should be a key goal of CF care. The objective of this workshop was to (1) review our understanding of the origins of CF lung disease, (2) determine gaps in the knowledge base that are most significant and most likely to enable prevention of CF lung disease, and (3) prioritize new research questions that will promote pulmonary health in both CF and other childhood lung diseases. The goal of this report is to provide recommendations for future research that will improve our understanding of pulmonary development in health and disease, improve outcome measures and biomarkers for early lung disease, and determine therapeutic targets and strategies to prevent the development of lung disease in children with CF.

The Forum of International Respiratory Societies has released a report entitled Respiratory Disease in the World: Realities of Today-Opportunities for Tomorrow. The report identifies five conditions that primarily contribute to the global burden of respiratory disease (asthma, chronic obstructive pulmonary disease, acute respiratory infections, tuberculosis, and lung cancer), and offers an action plan to prevent and treat those diseases. It describes the staggering magnitude of the global burden of lung disease: hundreds of millions of people suffer and four million people die prematurely from respiratory diseases each year. The situation is not hopeless, because most major respiratory illnesses are avoidable. Much of the disease burden can be mitigated by reducing exposure to indoor and outdoor air pollution, restraining tobacco use, and relieving urban overcrowding. Implementation of the strategies described in the Forum of International Respiratory Societies respiratory diseases report would have a profound effect on respiratory health, reduce economic costs, and enhance health equality in the world.

Airway epithelial cells and immune cells participate in the inflammatory process responsible for much of the pathology found in the lung of patients with cystic fibrosis (CF). Intense bronchial neutrophilic inflammation and release of proteases and oxygen radicals perpetuate the vicious cycle and progressively damage the airways. In vitro studies suggest that CF transmembrane conductance regulator (CFTR)-deficient airway epithelial cells display signalling abnormalities and aberrant intracellular processes which lead to transcription of inflammatory mediators. Several transcription factors, especially nuclear factor-κB, are activated. In addition, the accumulation of abnormally processed CFTR in the endoplasmic reticulum results in unfolded protein responses that trigger 'cell stress' and apoptosis leading to dysregulation of the epithelial cells and innate immune function in the lung, resulting in exaggerated and ineffective airway inflammation. Measuring airway inflammation is crucial for initiating treatment and monitoring its effect. No inflammatory biomarker predictive for the clinical course of CF lung disease is currently known, although neutrophil elastase seems to correlate with lung function decline. CF animal models mimicking human lung disease may provide an important insight into the pathogenesis of lung inflammation in CF and identify new therapeutic targets.

Pleural effusion is a rare complication of ventriculoperitoneal (VP) shunting, usually due to the migration of the VP shunt catheter into the thorax. Herein we report a neurologically disadvantaged child with a lobar holoprosencephaly and hydrocephalus, initially treated with a VP shunt, who years later developed recurrent right-sided pleural effusion ultimately confirmed to be a cerebrospinal fluid (CSF) hydrothorax without intra-thoracic migration of the distal shunt catheter. Thoracentesis was compatible with a transudative effusion. Given the presence of a persistent pleural effusion, beta-2 transferrin concentrations were measured, which yielded a positive result. Plain radiographs and head computed tomography (CT) showed a normally positioned, functional VP shunt. A spine CT myelogram to look for a spinal dural-thoracic CSF fistula was negative. A radionuclide CSF shunt study demonstrated normal functioning VP shunt with radiotracer accumulation within the peritoneum, with subsequent tracer rapidly accumulating in the right hemithorax. Video-assisted thoracoscopic (VATS) exploration with drainage of the pleural effusion and pleurodesis was then performed. No diaphragmatic defect or shunt tubing within the thorax was found and the procedure failed to resolve the effusion. The patient's recurrent effusion was ultimately resolved with intracranial endoscopic choroid plexus coagulation to decrease CSF output., (Copyright © 2011 Wiley Periodicals, Inc.)

Lung infections with Pseudomonas aeruginosa and other pathogens in cystic fibrosis (CF) cause progressive airway obstruction and tissue damage, the predominant cause of morbidity and mortality in CF. We investigated whether a recombinant adeno-associated virus type 5 (AAV5) vector expressing murine interleukin (IL)-10 (AAV5.Cbeta-mIL-10), a regulatory/anti-inflammatory cytokine, could decrease airway inflammation in IL-10 knockout mice chronically infected with mucoid P. aeruginosa. Mice that received AAV5.Cbeta-mIL10 through intratracheal inoculation produced IL-10 at an average of 25 000 pg/ml in the epithelial lining fluid (ELF) and 12 000 pg/g-lung tissue 6 weeks post-vector delivery, significantly higher levels than in placebo-treated mice. At 3 days post-infection, proinflammatory cytokines (IL-1beta, tumor necrosis factor (TNF)-alpha, macrophage inhibitory protein (MIP)-1alpha and (KC) in the ELF and lung homogenate were decreased (1-9 folds) in the AAV5.Cbeta-mIL10-treated mice accompanied by less pronounced and more localized neutrophil infiltration in lung sections, when compared with placebo-treated mice. These results suggest that AAV5.Cbeta-mIL10 induces IL-10 levels in the lungs mediating a significant anti-inflammatory response and making AAV-IL-10 gene transfer a potentially useful therapy in the treatment of CF lung disease.

Serine proteases released from neutrophils are central to the pathogenesis of cystic fibrosis lung disease and are considered to be obvious therapeutic targets. Neutrophil elastase digests key opsonins present in the lung and disrupts phagocytosis, allowing bacteria to persist despite established pulmonary inflammation. We have found that cathepsin G, an abundant serine protease found in human and murine neutrophils, has other roles in the development of suppurative lung diseases. Murine models of endobronchial inflammation indicate that cathepsin G inhibits airway defences and interferes with the host's ability to clear Pseudomonas aeruginosa from the lung with effects distinct from neutrophil elastase. We hypothesise that differences in bacterial killing are due to defects in innate defences created by proteolysis. Protein profiles of bronchoalveolar lavage of infected wild-type and cathepsin G-deficient mice were compared using two-dimensional polyacrylamide gel electrophoresis and tandem mass spectrometry. Four proteins in bronchoalveolar lavage were cleaved by cathepsin G. Serum amyloid P component leaked into the lung during acute infection and was digested by cathepsin G. Its cleavage products had greater binding to lipopolysaccharide and interfered with phagocytosis. These results indicate that cleaved serum amyloid P component acts as an anti-opsonin and interferes with bacterial clearance from the lung.

Although Pediatric Respiratory Medicine as a subspecialty has a long tradition and is well established in some countries, there is a wide variation across different regions of the world with regard to e.g. recognition of the discipline, training requirements, training facilities and clinical needs. This review summarizes the situation in North America (US and Canada), South America, Asia, Australia, Israel and Europe with the aim to highlight commonalities and differences and, ultimately, to further support continuous development of paediatric Respiratory Medicine Worldwide., ((c) 2009 Wiley-Liss, Inc.)

The adequacy of the pipeline of advanced pulmonary fellows to supply appropriately trained and committed researchers to enter academic careers was the major topic of a recently held National Heart Lung and Blood Institute NHLBI Workshop: Respiratory Medicine-Related Research Training for Adult and Pediatric Fellows. The special challenges and opportunities for the academic pediatric pulmonary trainee were discussed as part of this workshop and are discussed as a companion paper to the report by the full workshop. Surveys were conducted of pediatric chairs of academic departments and pediatric pulmonary training directors in the United States to examine the current status and opportunities for the pediatric pulmonary trainee. Strategies for recruitment and retention of talented young trainees and junior faculty are proposed., ((c) 2009 Wiley-Liss, Inc.)

We describe a case of acquired monosomy 7 myelodysplastic syndrome (MDS) in a boy with congenital adrenocortical insufficiency, genital anomalies, growth delay, skin hyperpigmentation, and chronic lung disease. Some of his clinical manifestations were suggestive of dyskeratosis congenita (DC), while other features resembled IMAGe association. DC has been linked to mutations in telomere maintenance genes. The genetic basis of IMAGe association is unknown, although mice harboring a mutation in a telomere maintenance gene, Tpp1, have adrenal hypoplasia congenita. We considered the possibility that this patient has a defect in telomere function resulting in features of both DC and IMAGe association., (Copyright 2009 Wiley-Liss, Inc.)

The adequacy of the pipeline of advanced pulmonary fellows to supply appropriately trained and committed researchers to enter academic careers was the major topic of a recently held National Heart Lung and Blood Institute NHLBI Workshop: Respiratory Medicine-Related Research Training for Adult and Pediatric Fellows. The special challenges and opportunities for the academic pediatric pulmonary trainee were discussed as part of this workshop and are presented as a companion article to the report by the full workshop. Surveys were conducted of pediatric chairs of academic departments and pediatric pulmonary training directors in the United States to examine the current status and opportunities for the pediatric pulmonary trainee. Strategies for recruitment and retention of talented young trainees and junior faculty are proposed.

Previous studies have demonstrated that delivery of a recombinant adeno-associated virus (AAV) vector encoding the complete human cystic fibrosis transmembrane regulator (CFTR) cDNA (tgAAVCF) to the nose, sinus, and lungs of subjects with cystic fibrosis (CF) was safe and well tolerated. In a small randomized, double-blind study of three doses of aerosolized tgAAVCF or placebo at 30-day intervals, encouraging but non-significant trends in pulmonary function and induced sputum interleukin 8 (IL-8) levels were seen at early time points. This larger study was conducted to verify these trends. One hundred and two subjects aged 12 years and older with mild-to-moderate cystic fibrosis (forced expiratory flow in 1 sec [FEV1]:60% predicted) were randomized to two aerosolized doses of 1x10(13)DNase-resistant particles of tgAAVCF (n=51) or matching placebo (n=51) administered 30 days apart. Although tgAAVCF was well tolerated, the study did not meet its primary efficacy end point of statistically significant improvement in FEV1 30 days after initial administration of tgAAVCF compared with placebo. There were no significant differences in spirometric lung function over time, induced sputum biologic markers, or days of antibiotic use in either treatment group. Thus repeated doses of aerosolized tgAAVCF were safe and well tolerated, but did not result in significant improvement in lung function over time. Because gene transfer is the simplest, most basic way to correct the underlying genetic defect that leads to disease in CF, further research is warranted to develop an effective gene transfer agent for the treatment of CF.

Despite its apparent benefits, high-dose ibuprofen has been infrequently applied to children with cystic fibrosis. We have noted a decrease in the use of high-dose ibuprofen at our pediatric cystic fibrosis center during the past decade. In this retrospective study, we examined our clinical experience with high-dose ibuprofen and other anti-inflammatory drugs in cystic fibrosis patients. The medical records of all patients, ages 5 to 18 years, followed at the cystic fibrosis center from 1995 to 2002, were reviewed and children were classified into two cohorts: ibuprofen-treated and untreated groups. Patterns of ibuprofen use and pharmacokinetics in treated patients, and for patients who discontinued ibuprofen, the reasons for stopping the medication, including adverse effects, were assessed. Pulmonary function decline and hospitalization rates for each group were compared, examining both intent to treat and patients who continued therapy for at least 4 years. Nearly half of the patients in our pediatric cystic fibrosis center who were prescribed with high-dose ibuprofen discontinued therapy due to adverse events, not because of poor adherence or patient choice. Neither use of high-dose ibuprofen nor its cessation resulted in a significant change in the rate of decline in pulmonary function or influenced hospitalization rates.

The cystic fibrosis airway is susceptible to Pseudomonas aeruginosa infection, which stimulates an intense inflammatory response leading to airway obstruction and bronchiectasis. Neutrophils migrate into the airway, and once there, release high concentrations of neutral serine proteases during phagocytosis and in death. In particular, neutrophil elastase is central to progression of bronchiectasis by interfering with bacterial clearance and directly perpetuating the inflammatory response in the airway. Using a murine model of endobronchial inflammation, we found that a different neutrophil-derived serine protease, cathepsin G, inhibited the host's ability to clear Pseudomonas from the lung, based on a 1-log reduction in bacteria recovered from cathepsin G-deficient mice. Higher antibody concentrations were found in respiratory epithelial lining fluid from mice lacking cathepsin G, but there was no difference in other opsonins, such as surfactant proteins A and D. Chemokine levels measured in the lung correlated with bacterial burden and not the animal's genotype, indicating that airway inflammation was not affected by the presence (or absence) of specific serine proteases. These findings suggest that cathepsin G interferes with airway defenses, showing that proteases other than neutrophil elastase have roles in the pathogenesis of suppurative airway diseases.

Primary ciliary dyskinesia is a genetic disorder causing dysfunctional motility of cilia and impaired mucociliary clearance, resulting in a myriad of clinical manifestations including recurrent sinopulmonary disease, laterality defects and infertility. The heterogenous clinical presentation of primary ciliary dyskinesia and the limitations of transmission electron microscopy to assess ultrastructural defects within the cilium often delay diagnosis. Recent advances in the understanding of the basic biology and function of the cilium have led to potential diagnostic alternatives, including ciliary beat analysis and nasal nitric oxide measurements. Moreover, the identification of disease-causing mutations could lead to the development of comprehensive genetic testing that may overcome many of the current diagnostic limitations. Although the clinical manifestations of primary ciliary dyskinesia have been recognised for over a century, there are few studies examining treatments and standards of care have yet to be established. Multicentre collaborative efforts have been established in North America and Europe, which should help to develop standardised approaches to the diagnosis and treatment of primary ciliary dyskinesia.

Primary ciliary dyskinesia is an autosomal recessive genetic disease that results in impaired mucociliary clearance causing progressive involvement of the upper and lower respiratory tract, characterized by airway obstruction and recurrent infections of the lungs, middle ear and paranasal sinuses. Other clinical manifestations include situs inversus totalis and male infertility. Recently, neonatal respiratory distress has been found to be a common clinical presentation of patients with primary ciliary dyskinesia, indicating that this is an important symptom complex in early life for this condition. The diagnosis requires a high index of suspicion, but primary ciliary dyskinesia must be considered in any term neonate who develops respiratory distress or persistent hypoxemia and has situs inversus or an affected sibling. Moreover, further evaluation is warranted in children who had transient respiratory distress in newborn period and subsequently develop persistent cough or chronic otitis media.

Context: This multicenter, randomized, controlled, crossover trial of prepubertal children with cystic fibrosis (CF) tests the hypotheses that recombinant human GH (rhGH) treatment 1) improves height, weight, lean mass, and bone content irrespective of baseline measures; 2) improves clinical status and quality of life; and 3) has continued effect after cessation after 1 yr of treatment., Methods: Sixty-one prepubertal subjects (

Despite favorable DNA transfer efficiency, gene expression from recombinant adeno-associated virus (rAAV2) vectors in the lung has been variable in the context of cystic fibrosis (CF) gene therapy. This is due, in part, to the large size of the CF transmembrane regulator (CFTR)-coding sequence which necessitates the use of compact endogenous promoter elements versus stronger exogenous promoters. We evaluated the possibility that gene expression from rAAV could be improved by using AAV capsid serotypes with greater tropism for the apical surface of airway cells (i.e. rAAV5 or rAAV1) and/or using strong promoters such as the cytomegalovirus (CMV) enhancer/chicken beta-actin hybrid (Cbeta) promoter. The relative activity of the CMV immediate-early (CMVie) promoter, the Cbeta promoter, and the Cbeta promoter with a downstream woodchuck hepatitis virus post-transcriptional regulatory element (wpre) were assessed in vitro and in vivo in C57\Bl6 mice using human alpha-1 antitrypsin (hAAT) as a secreted reporter. In vivo, the Cbeta-AAT-wpre group achieved maximum serum levels of 1.5 mg/ml of hAAT. AAV capsid serotypes were then compared in vivo utilizing the transcriptionally optimized CB-wpre cassette in rAAV serotype 1, 2 or 5 capsids (rAAV1, rAAV2, and rAAV5), utilizing luciferase as a reporter to compare expression over a wide dynamic range. The pulmonary luciferase levels at 8 weeks were similar in rAAV5 and rAAV1 groups (2.9 x 10(6) relative light units (RLU)/g tissue and 2.7 x 10(6) RLU/g tissue, respectively), both of which were much higher than rAAV2. Although the advantage of rAAV5 over rAAV2 in the lung has already been described, the availability of another serotype (rAAV1) capable of efficient gene transfer in the lung could be useful., (Copyright 2005 John Wiley & Sons, Ltd.)

Objectives: Studies of growth hormone (GH) effectiveness in prepubertal children with cystic fibrosis (CF) have been published previously. We present a retrospective study of GH treatment in adolescents with CF., Study Design: We performed a retrospective evaluation of data from 25 pubertal adolescents (ages 13 years 4 months to 16 years 11 months, Tanner stage III or IV). Thirteen (4 F) were followed for 1 year, then received 1 year of treatment with GH (GHTX). We compared the results with a 'control' group of 12 (4 F) whose growth was followed for 1 year (NonTX) but who were not treated with GH at the time of this review. Anthropometric data included: height, weight, lean tissue mass (LTM) and bone mineral content (BMC). Pulmonary function, number of hospitalizations, glycosylated haemoglobin (HbA1c), random blood glucose levels, IGF-I, oestradiol and testosterone levels are also reported., Results: There was no difference between the groups at baseline. After 1 year, GHTX had significantly greater height and weight velocity, height and weight Z-scores, body mass index (BMI), LTM and BMC. Absolute pulmonary function was better and hospitalizations were fewer in the GHTX. No subject developed glucose intolerance or had any other side-effects., Conclusion: These results suggest that GH use in pubertal adolescents with CF safely improves height, body weight, bone mineralization and clinical status.

The progression of lung disease in cystic fibrosis (CF) is characterized by an exuberant inflammatory response mounted by the respiratory epithelium that is further exacerbated by bacterial infection. Recent studies have demonstrated upregulation of nuclear factor-kappaB (NF-kappaB) in response to infection in genetically modified cell culture models, which is associated with expression of interleukin (IL)-8. Using human airway epithelial cells grown in primary culture, we examined in vitro activation of NF-kappaB in cells isolated from five CF (DeltaF508/DeltaF508) and three non-CF (NCF) patients in response to Pseudomonas aeruginosa. Immunofluorescence, gel-shift, and immunoblot assays demonstrated a rapid translocation of NF-kappaB subunits (p50 and p65) to the nucleus in both CF and NCF cell cultures. However, nuclear extracts from CF cells both before and following P. aeruginosa stimulation revealed elevated NF-kappaB activation compared with NCF cells. Additionally, elevated nuclear levels of the NF-kappaB inhibitor IkappaBalpha were detected in nuclei of CF cells after P. aeruginosa stimulation, but this increase was transient. There was no difference in IL-8 mRNA levels between CF and NCF cells early after stimulation, whereas expression was higher and sustained in CF cells at later times. Our results also demonstrated increased baseline translocation of NF-kappaB to nuclei of primary CF epithelial cell cultures, but intranuclear IkappaBalpha may initially block its effects following P. aeruginosa stimulation. Thus, IL-8 mRNA expression was prolonged after P. aeruginosa stimulation in CF epithelial cells, and this sustained IL-8 expression may contribute to the excessive inflammatory response in CF.