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Phadnis S, Muthu V, Sehgal IS, Prasad KT, Dhooria S, Aggarwal AN, Agarwal R. Bronchiectasis Severity Index and FACED scores in patients with allergic bronchopulmonary aspergillosis complicating asthma: do they correlate with immunological severity or high-attenuation mucus? J Asthma 2024:1-9. [PMID: 38520686 DOI: 10.1080/02770903.2024.2334901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/20/2024] [Indexed: 03/25/2024]
Abstract
Background: The utility of two disease-severity indices, namely bronchiectasis severity index (BSI) and FACED score in allergic bronchopulmonary aspergillosis (ABPA) remains unknown.Objective: To correlate the BSI and FACED scores with immunological parameters (serum IgE [total and A. fumigatus-specific], A. fumigatus-specific IgG, blood eosinophil count), and high-attenuation mucus on chest computed tomography in ABPA. The secondary objectives were to evaluate the correlation between BSI and FACED scores and correlate the BSI/FACED scores with the bronchiectasis health questionnaire (BHQ) and Saint George's Respiratory Questionnaire (SGRQ).Methods: We included treatment-naïve ABPA subjects with bronchiectasis in a prospective observational study. We computed the BSI and FACED scores for each subject before initiating treatment. The subjects also completed two quality-of-life questionnaires (BHQ and SGRQ).Results: We included 91 subjects. The mean (standard deviation) BSI and FACED scores were 3.43 (3.39) and 1.43 (1.27). We found no correlation between BSI or FACED with any immunological parameter or high-attenuation mucus. There was a strong correlation between BSI and FACED scores (r = 0.76, p < 0.001). We found a weak correlation between BSI and BHQ/SGRQ and FACED and SGRQ.Conclusion: We found no correlation between BSI and FACED with immunological parameters in ABPA. However, we found a significant correlation between BSI and FACED and a weak correlation between SGRQ and BHQ. ABPA likely requires a separate disease-severity scoring system.
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Affiliation(s)
- Shruti Phadnis
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (India)
| | - Valliappan Muthu
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (India)
| | - Inderpaul S Sehgal
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (India)
| | - Kuruswamy T Prasad
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (India)
| | - Sahajal Dhooria
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (India)
| | - Ashutosh N Aggarwal
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (India)
| | - Ritesh Agarwal
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh (India)
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Ruhluel D, Fisher L, Barton TE, Leighton H, Kumar S, Amores Morillo P, O’Brien S, Fothergill JL, Neill DR. Secondary messenger signalling influences Pseudomonas aeruginosa adaptation to sinus and lung environments. THE ISME JOURNAL 2024; 18:wrae065. [PMID: 38647527 PMCID: PMC11102083 DOI: 10.1093/ismejo/wrae065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 03/08/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024]
Abstract
Pseudomonas aeruginosa is a cause of chronic respiratory tract infections in people with cystic fibrosis (CF), non-CF bronchiectasis, and chronic obstructive pulmonary disease. Prolonged infection allows the accumulation of mutations and horizontal gene transfer, increasing the likelihood of adaptive phenotypic traits. Adaptation is proposed to arise first in bacterial populations colonizing upper airway environments. Here, we model this process using an experimental evolution approach. Pseudomonas aeruginosa PAO1, which is not airway adapted, was serially passaged, separately, in media chemically reflective of upper or lower airway environments. To explore whether the CF environment selects for unique traits, we separately passaged PAO1 in airway-mimicking media with or without CF-specific factors. Our findings demonstrated that all airway environments-sinus and lungs, under CF and non-CF conditions-selected for loss of twitching motility, increased resistance to multiple antibiotic classes, and a hyper-biofilm phenotype. These traits conferred increased airway colonization potential in an in vivo model. CF-like conditions exerted stronger selective pressures, leading to emergence of more pronounced phenotypes. Loss of twitching was associated with mutations in type IV pili genes. Type IV pili mediate surface attachment, twitching, and induction of cAMP signalling. We additionally identified multiple evolutionary routes to increased biofilm formation involving regulation of cyclic-di-GMP signalling. These included the loss of function mutations in bifA and dipA phosphodiesterase genes and activating mutations in the siaA phosphatase. These data highlight that airway environments select for traits associated with sessile lifestyles and suggest upper airway niches support emergence of phenotypes that promote establishment of lung infection.
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Affiliation(s)
- Dilem Ruhluel
- Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Ronald Ross Building, 8 West Derby Street, Liverpool, United Kingdom
| | - Lewis Fisher
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Thomas E Barton
- Division of Molecular Microbiology, University of Dundee, Dow Street, Dundee, United Kingdom
| | - Hollie Leighton
- Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Ronald Ross Building, 8 West Derby Street, Liverpool, United Kingdom
| | - Sumit Kumar
- Division of Molecular Microbiology, University of Dundee, Dow Street, Dundee, United Kingdom
| | - Paula Amores Morillo
- Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Ronald Ross Building, 8 West Derby Street, Liverpool, United Kingdom
| | - Siobhan O’Brien
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin, 2, Ireland
| | - Joanne L Fothergill
- Department of Clinical Infection, Microbiology and Immunology, University of Liverpool, Ronald Ross Building, 8 West Derby Street, Liverpool, United Kingdom
| | - Daniel R Neill
- Division of Molecular Microbiology, University of Dundee, Dow Street, Dundee, United Kingdom
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3
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Franklin M, Minshall ME, Pontenani F, Devarajan S. Impact of Pseudomonas aeruginosa on resource utilization and costs in patients with exacerbated non-cystic fibrosis bronchiectasis. J Med Econ 2024; 27:671-677. [PMID: 38646702 DOI: 10.1080/13696998.2024.2340382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 04/04/2024] [Indexed: 04/23/2024]
Abstract
AIMS Non-cystic fibrosis bronchiectasis (NCFB) is a chronic progressive respiratory disorder occurring at a rate ranging from 4.2 to 278.1 cases per 100,000 persons, depending on age, in the United States. For many patients with NCFB, the presence of Pseudomonas aeruginosa (PA) makes treatment more complicated and typically has worse outcomes. Management of NCFB can be challenging, warranting a better understanding of the burden of illness for NCFB, treatments applied, healthcare resources used, and subsequent treatment costs. Comparing patients diagnosed with exacerbated NCFB, with or without PA on antibiotic utilization, treatments, and healthcare resources utilization and costs was the purpose of this study. MATERIALS AND METHODS This was a retrospective cohort study of commercial claims from IQVIA's PharMetrics Plus database (January 1,2006-December 31, 2020). Study patients with a diagnosis of NCFB were stratified into two groups based on the presence or absence of PA, then followed to identify demographic characteristics, comorbid conditions, antibiotic treatment regimen prescribed, healthcare resources utilized, and costs of care. RESULTS The results showed that patients with exacerbated NCFB who were PA+ had significantly more oral antibiotic fills per patient per year, more inpatient admissions with a longer length of stay, and more outpatient encounters than those who were PA-. For costs, PA+ patients also had significantly greater total healthcare costs per patient when compared to those who were PA-. CONCLUSION Exacerbated NCFB with PA+ was associated with increased antibiotic usage, greater resource utilization, and increased costs. The major contributor to the cost differences was the use of inpatient services. Treatment strategies aimed at reducing the need for inpatient treatment could lessen the disparities observed in patients with NCFB.
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Affiliation(s)
- Meg Franklin
- Franklin Pharmaceutical Consulting, Cary, NC, USA
- PRECISIONheor, Boston, MA, USA
| | | | | | - Sunjay Devarajan
- Department of Pulmonary/Critical Care Medicine, Section of Pulmonary and Critical Care Medicine, Baylor College of Medicine, Houston, TX, USA
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4
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Venuti F, Gaviraghi A, De Nicolò A, Stroffolini G, Longo BM, Di Vincenzo A, Ranzani FA, Quaranta M, Romano F, Catellani E, Marchiaro C, Cinnirella G, D'Avolio A, Bonora S, Calcagno A. Real-Life Experience of Continuously Infused Ceftolozane/Tazobactam in Patients with Bronchiectasis and Multidrug-Resistant Pseudomonas aeruginosa Infection in the Outpatient Setting. Antibiotics (Basel) 2023; 12:1214. [PMID: 37508309 PMCID: PMC10376517 DOI: 10.3390/antibiotics12071214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
(1) Background: Ceftolozane/tazobactam (C/T) is a novel β-lactam/β-lactamase inhibitor with excellent activity against the multidrug-resistant (MDR) P. aeruginosa. Continuous infusion (CI) dosing allows the optimization of pharmacokinetic and pharmacodynamic (PK/PD) properties of β-lactam antibiotics and may support patients' treatment as outpatients. (2) Methods: Adult patients receiving their entire course of C/T as a CI in the outpatient setting were retrospectively included in the study. The primary outcome evaluated was clinical resolution. The secondary outcomes evaluated were PK/PD target attainment (ƒT > 4 × MIC) and microbiologic clearance at the end of treatment. Therapeutic drug monitoring to assess C/T concentration was performed. (3) Results: Three patients were enrolled in the study and received 9 g of C/T in CI every 24 h. One patient received an additional course of antimicrobial therapy due to disease exacerbation six months after initial treatment, accounting for four evaluated treatments. The primary outcome was achieved in 3/4 treatments and the secondary outcome was achieved in 4/4 and 3/3, respectively. In all patients, free ceftolozane concentrations were >10 times higher than the EUCAST breakpoint (4 mg/L). (4) Conclusions: Elastomeric infusion of C/T delivered in CI can be an effective and convenient way to treat acute diseases caused by MDR-P. aeruginosa, avoid hospital admission, and contribute to infection control strategies. Despite the small number of enrolled patients, clinical and microbiological results support this strategy.
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Affiliation(s)
- Francesco Venuti
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino at the Amedeo di Savoia Hospital, ASL Città di Torino, Corso Svizzera 164, 10149 Torino, Italy
| | - Alberto Gaviraghi
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino at the Amedeo di Savoia Hospital, ASL Città di Torino, Corso Svizzera 164, 10149 Torino, Italy
| | - Amedeo De Nicolò
- Laboratory of Clinical Pharmacology and Pharmacogenetics, Department of Medical Sciences, University of Turin, 10149 Turin, Italy
| | - Giacomo Stroffolini
- Department of Infectious-Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Via Don A. Sempreboni, 5, 37024 Verona, Italy
| | - Bianca Maria Longo
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino at the Amedeo di Savoia Hospital, ASL Città di Torino, Corso Svizzera 164, 10149 Torino, Italy
| | - Alessia Di Vincenzo
- Laboratory of Clinical Pharmacology and Pharmacogenetics, Department of Medical Sciences, University of Turin, 10149 Turin, Italy
| | - Fabio Antonino Ranzani
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino at the Amedeo di Savoia Hospital, ASL Città di Torino, Corso Svizzera 164, 10149 Torino, Italy
| | - Matilde Quaranta
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino at the Amedeo di Savoia Hospital, ASL Città di Torino, Corso Svizzera 164, 10149 Torino, Italy
| | - Francesca Romano
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino at the Amedeo di Savoia Hospital, ASL Città di Torino, Corso Svizzera 164, 10149 Torino, Italy
| | - Eleonora Catellani
- ASL Città di Torino, Amedeo di Savoia Hospital, Corso Svizzera 164, 10149 Torino, Italy
| | - Carlotta Marchiaro
- ASL Città di Torino, Amedeo di Savoia Hospital, Corso Svizzera 164, 10149 Torino, Italy
| | - Giacoma Cinnirella
- ASL Città di Torino, Amedeo di Savoia Hospital, Corso Svizzera 164, 10149 Torino, Italy
| | - Antonio D'Avolio
- Laboratory of Clinical Pharmacology and Pharmacogenetics, Department of Medical Sciences, University of Turin, 10149 Turin, Italy
| | - Stefano Bonora
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino at the Amedeo di Savoia Hospital, ASL Città di Torino, Corso Svizzera 164, 10149 Torino, Italy
| | - Andrea Calcagno
- Unit of Infectious Diseases, Department of Medical Sciences, University of Torino at the Amedeo di Savoia Hospital, ASL Città di Torino, Corso Svizzera 164, 10149 Torino, Italy
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Rosenboom I, Oguz S, Lüdemann IM, Ringshausen FC, Rademacher J, Sedlacek L, Tümmler B, Cramer N. Pseudomonas aeruginosa population genomics among adults with bronchiectasis across Germany. ERJ Open Res 2023; 9:00156-2023. [PMID: 37377651 PMCID: PMC10291309 DOI: 10.1183/23120541.00156-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 03/20/2023] [Indexed: 06/29/2023] Open
Abstract
Genome sequencing of 130 Pseudomonas aeruginosa isolates from 110 bronchiectasis patients identified a few dominant clones common in the global bacterial population and numerous rare clones infrequently seen in the environment or other human infections https://bit.ly/3lIfD2X.
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Affiliation(s)
- Ilona Rosenboom
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Hannover, Germany
| | - Sibel Oguz
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Idalina M. Lüdemann
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Hannover, Germany
| | - Felix C. Ringshausen
- German Center for Infection Research (DZIF), Hannover, Germany
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany
- European Reference Network for Rare and Complex Lung Diseases (ERN-LUNG), Frankfurt am Main, Germany
| | - Jessica Rademacher
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany
| | - Ludwig Sedlacek
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Burkhard Tümmler
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research, Hannover, Germany
| | - Nina Cramer
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Hannover, Germany
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6
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Hill DB, Button B, Rubinstein M, Boucher RC. Physiology and pathophysiology of human airway mucus. Physiol Rev 2022; 102:1757-1836. [PMID: 35001665 PMCID: PMC9665957 DOI: 10.1152/physrev.00004.2021] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 01/27/2023] Open
Abstract
The mucus clearance system is the dominant mechanical host defense system of the human lung. Mucus is cleared from the lung by cilia and airflow, including both two-phase gas-liquid pumping and cough-dependent mechanisms, and mucus transport rates are heavily dependent on mucus concentration. Importantly, mucus transport rates are accurately predicted by the gel-on-brush model of the mucociliary apparatus from the relative osmotic moduli of the mucus and periciliary-glycocalyceal (PCL-G) layers. The fluid available to hydrate mucus is generated by transepithelial fluid transport. Feedback interactions between mucus concentrations and cilia beating, via purinergic signaling, coordinate Na+ absorptive vs Cl- secretory rates to maintain mucus hydration in health. In disease, mucus becomes hyperconcentrated (dehydrated). Multiple mechanisms derange the ion transport pathways that normally hydrate mucus in muco-obstructive lung diseases, e.g., cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), non-CF bronchiectasis (NCFB), and primary ciliary dyskinesia (PCD). A key step in muco-obstructive disease pathogenesis is the osmotic compression of the mucus layer onto the airway surface with the formation of adherent mucus plaques and plugs, particularly in distal airways. Mucus plaques create locally hypoxic conditions and produce airflow obstruction, inflammation, infection, and, ultimately, airway wall damage. Therapies to clear adherent mucus with hydrating and mucolytic agents are rational, and strategies to develop these agents are reviewed.
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Affiliation(s)
- David B Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Joint Department of Biomedical Engineering, The University of North Carolina and North Carolina State University, Chapel Hill, North Carolina
| | - Brian Button
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael Rubinstein
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Mechanical Engineering and Materials Science, Biomedical Engineering, Physics, and Chemistry, Duke University, Durham, North Carolina
| | - Richard C Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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8
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Zhou Y, Mu W, Zhang J, Wen SW, Pakhale S. Global prevalence of non-tuberculous mycobacteria in adults with non-cystic fibrosis bronchiectasis 2006-2021: a systematic review and meta-analysis. BMJ Open 2022; 12:e055672. [PMID: 35914904 PMCID: PMC9345037 DOI: 10.1136/bmjopen-2021-055672] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE To accurately estimate the global prevalence of non-tuberculous mycobacteria (NTM) in adults with non-cystic fibrosis (non-CF) bronchiectasis and to determine the proportion of NTM species and subspecies in clinical patients from 2006 to 2021. DESIGN Systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES Medline, Embase, Cochrane Library and Web of Science were searched for articles published between 2006 and 2021. ELIGIBILITY CRITERIA FOR SELECTING STUDIES We included all the prospective or retrospective studies without language restrictions and all patients were adults (≥18 years of age) with non-CF bronchiectasis. The studies estimated the effect size of the prevalence of NTM with a sample size ≥40, and patients were registered in and after 2006. DATA EXTRACTION AND SYNTHESIS Two reviewers screened the titles, abstracts and full texts independently. Relevant information was extracted and curated into tables. Risk of bias was evaluated following the Cochrane Collaboration's tool. Meta-analysis was performed with software R Statistics V.3.6.3 using random effect model with 95% CI. I2 index and Q statistics were calculated to assess the heterogeneity, and mixed-effects meta-regression analyses were performed to identify the sources of heterogeneity. The proportions of NTM subspecies were examined using Shapiro-Wilk normality test in R. RESULTS Of all the 2014 studies yielded, 24 met the inclusion criteria. Of these, 14 were identified to be randomised controlled studies and included for an accurate estimation. The global prevalence of NTM in adults with non-CF bronchiectasis from 2006 to 2021 was estimated to be approximately 10%, with great variations primarily due to geographical location. Mycobacterium avium complex was the most common subspecies, followed by Mycobacterium simiae and Mycobacterium gordonae. CONCLUSIONS The prevalence of NTM in adults with non-CF bronchiectasis has been on the rise and the most common subspecies changed greatly in recent years. More cohort studies should be done in many countries and regions for future estimates. PROSPERO REGISTRATION NUMBER CRD42020168473.
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Affiliation(s)
- Yunchun Zhou
- Department of Pulmonary and Critical Care Medicine, People's Hospital of Yuxi City, Yuxi, Yunnan, China
- The Sixth Affiliated Hospital of Kunming Medical University, Yuxi, Yunnan, China
| | - Wei Mu
- Department of Clinical Pharmacology, The Second Affiliated Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Jihua Zhang
- Department of Pulmonary and Critical Care Medicine, People's Hospital of Yuxi City, Yuxi, Yunnan, China
- The Sixth Affiliated Hospital of Kunming Medical University, Yuxi, Yunnan, China
| | - Shi Wu Wen
- The Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Smita Pakhale
- The Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Division of Respiratory Medicine, The Ottawa Hospital, Ottawa, Ontario, Canada
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9
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Abstract
Bronchiectasis is a complex, heterogeneous disorder defined by both a radiological abnormality of permanent bronchial dilatation and a clinical syndrome. There are multiple underlying causes including severe infections, mycobacterial disease, autoimmune conditions, hypersensitivity disorders, and genetic conditions. The pathophysiology of disease is understood in terms of interdependent concepts of chronic infection, inflammation, impaired mucociliary clearance, and structural lung damage. Neutrophilic inflammation is characteristic of the disease, with elevated levels of harmful proteases such as neutrophil elastase associated with worse outcomes. Recent data show that neutrophil extracellular trap formation may be the key mechanism leading to protease release and severe bronchiectasis. Despite the dominant of neutrophilic disease, eosinophilic subtypes are recognized and may require specific treatments. Neutrophilic inflammation is associated with elevated bacterial loads and chronic infection with organisms such as Pseudomonas aeruginosa. Loss of diversity of the normal lung microbiota and dominance of proteobacteria such as Pseudomonas and Haemophilus are features of severe bronchiectasis and link to poor outcomes. Ciliary dysfunction is also a key feature, exemplified by the rare genetic syndrome of primary ciliary dyskinesia. Mucus symptoms arise through goblet cell hyperplasia and metaplasia and reduced ciliary function through dyskinesia and loss of ciliated cells. The contribution of chronic inflammation, infection, and mucus obstruction leads to progressive structural lung damage. The heterogeneity of the disease is the most challenging aspect of management. An understanding of the pathophysiology of disease and their biomarkers can help to guide personalized medicine approaches utilizing the concept of "treatable traits."
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Affiliation(s)
- Holly R Keir
- Scottish Centre for Respiratory Research, University of Dundee, Dundee, United Kingdom
| | - James D Chalmers
- Scottish Centre for Respiratory Research, University of Dundee, Dundee, United Kingdom
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