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Siora A, Vontetsianos A, Chynkiamis N, Anagnostopoulou C, Bartziokas K, Anagnostopoulos N, Rovina N, Bakakos P, Papaioannou AI. Small airways in asthma: From inflammation and pathophysiology to treatment response. Respir Med 2024; 222:107532. [PMID: 38228215 DOI: 10.1016/j.rmed.2024.107532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/02/2024] [Accepted: 01/13/2024] [Indexed: 01/18/2024]
Abstract
Small airways are characterized as those with an inner diameter less than 2 mm and constitute a major site of pathology and inflammation in asthma disease. It is estimated that small airways dysfunction may occur before the emergence of noticeable symptoms, spirometric abnormalities and imaging findings, thus characterizing them as "the quiet or silent zone" of the lungs. Despite their importance, measuring and quantifying small airways dysfunction presents a considerable challenge due to their inaccessibility in usual functional measurements, primarily due to their size and peripheral localization. Several pulmonary function tests have been proposed for the assessment of the small airways, including impulse oscillometry, nitrogen washout, body plethysmography, as well as imaging methods. Nevertheless, none of these methods has been established as the definitive "gold standard," thus, a combination of them should be used for an effective assessment of the small airways. Widely used asthma treatments seem to also affect several parameters of the small airways. Emerging biologic treatments show promising results in reducing small airways inflammation and remodelling, providing evidence for potential alterations in the disease's progression and outcomes. These novel therapies have implications not only in the clinical aspects of asthma but also in its inflammatory and functional aspects.
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Affiliation(s)
- Anastasia Siora
- 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens, School of Medicine, Sotiria Chest Hospital, Athens, Greece.
| | - Angelos Vontetsianos
- 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens, School of Medicine, Sotiria Chest Hospital, Athens, Greece
| | - Nikolaos Chynkiamis
- 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens, School of Medicine, Sotiria Chest Hospital, Athens, Greece
| | - Christina Anagnostopoulou
- 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens, School of Medicine, Sotiria Chest Hospital, Athens, Greece
| | | | - Nektarios Anagnostopoulos
- 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens, School of Medicine, Sotiria Chest Hospital, Athens, Greece
| | - Nikoletta Rovina
- 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens, School of Medicine, Sotiria Chest Hospital, Athens, Greece
| | - Petros Bakakos
- 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens, School of Medicine, Sotiria Chest Hospital, Athens, Greece
| | - Andriana I Papaioannou
- 1st Department of Respiratory Medicine, National and Kapodistrian University of Athens, School of Medicine, Sotiria Chest Hospital, Athens, Greece
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Bozier J, Jeagal E, Robinson PD, Prisk GK, Chapman DG, King GG, Thamrin C, Rutting S. The effect of O 2 and CO 2 cross-sensitivity sensor error in the Eco Medics Exhalyzer D device on measures of conductive and acinar airway function. ERJ Open Res 2022; 8:00614-2021. [PMID: 35854872 PMCID: PMC9289373 DOI: 10.1183/23120541.00614-2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/17/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction The multiple breath nitrogen washout (MBNW) test provides important clinical information in obstructive airways diseases. Recently, a significant cross-sensitivity error in the O2 and CO2 sensors of a widely used commercial MBNW device (Exhalyzer D, Eco Medics AG, Duernten, Switzerland) was detected, which leads to overestimation of N2 concentrations. Significant errors in functional residual capacity (FRC) and lung clearance index (LCI) have been reported in infants and children. This study investigated the impact in adults, and on additional important indices reflecting conductive (Scond) and acinar (Sacin) ventilation heterogeneity, in health and disease. Methods Existing MBNW measurements of 27 healthy volunteers, 20 participants with asthma and 16 smokers were reanalysed using SPIROWARE V 3.3.1, which incorporates an error correction algorithm. Uncorrected and corrected indices were compared using paired t-tests and Bland–Altman plots. Results Correction of the sensor error significantly lowered FRC (mean difference 9%) and LCI (8–10%) across all three groups. Scond was higher following correction (11%, 14% and 36% in health, asthma and smokers, respectively) with significant proportional bias. Sacin was significantly lower following correction in the asthma and smoker groups, but the effect was small (2–5%) and with no proportional bias. Discussion The O2 and CO2 cross-sensitivity sensor error significantly overestimated FRC and LCI in adults, consistent with data in infants and children. There was a high degree of underestimation of Scond but minimal impact on Sacin. The presence of significant proportional bias indicates that previous studies will require reanalysis to confirm previous findings and to allow comparability with future studies. O2 and CO2 cross-sensitivity sensor error in the Exhalyzer D device significantly overestimates FRC and LCI in adults, consistent with infants and children. Importantly, there was a high degree of underestimation of Scond, but minimal impact on Sacin.https://bit.ly/3HcH3Tp
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Dos Santos DO, Perossi L, Perossi J, de Souza Simoni LH, Holtz M, Moroli RG, Baddini-Martinez JA, Gastaldi AC. Comparative evaluation of expiratory airflow limitation between patients with COPD and BE using IOS. Sci Rep 2021; 11:4524. [PMID: 33633234 PMCID: PMC7907066 DOI: 10.1038/s41598-021-84028-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 01/04/2021] [Indexed: 11/21/2022] Open
Abstract
Impulse oscillometry (IOS) allows evaluation of the compartmentalized resistance and reactance of the respiratory system, distinguishing central and peripheral obstruction. The IOS measurements are getting attention in the diagnosis and differentiation of chronic respiratory diseases. However, no data are available in the literature to differentiate between COPD and BE using IOS parameters. We aimed to evaluate the feasibility of IOS in the diagnosis of bronchiectasis non-cystic fibrosis (BE) in comparison to COPD. Whole breath, inspiration, expiration, and inspiratory-expiratory difference (Δ) were evaluated based on the IOS parameters: total resistance (R5), central airway resistance (R20), peripheral airway resistance (R5-R20), reactance (X5), reactance area (AX), and resonance frequency (Fres). Fifty-nine subjects (21 Healthy, 19 BE, and 19 COPD) participated in this study. It was observed a significant difference in the comparison of healthy and pulmonary disease groups (BE and COPD) for total breathing (R5-R20, X5, AX, and Fres), inspiratory phase (R5 and R5-R5), and expiratory phase (R5-R20 and X5). The comparison between BE and COPD groups showed significant difference in the expiratory phase for resistance at 5 and 20 Hz and, ΔR5 and ΔR20. The IOS evidenced an increase of R5, R20 and R5-R20 in patients with BE and COPD when compared to healthy subjects. Expiratory measures of IOS revealed increased airway resistance in COPD compared to BE patients who had similar FEV1 measured by spirometry, however, further studies are needed to confirm these differences.
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Affiliation(s)
- Daniele Oliveira Dos Santos
- Department of Health Sciences, Graduate Program in Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, 14049-900, Brazil
| | - Larissa Perossi
- Department of Health Sciences, Graduate Program in Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, 14049-900, Brazil
| | - Jéssica Perossi
- Department of Health Sciences, Graduate Program in Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, 14049-900, Brazil
| | - Letícia Helena de Souza Simoni
- Department of Health Sciences, Graduate Program in Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, 14049-900, Brazil
| | - Mayara Holtz
- Department of Health Sciences, Graduate Program in Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, 14049-900, Brazil
| | - Ricardo Grassi Moroli
- Department of Health Sciences, Graduate Program in Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, 14049-900, Brazil
| | | | - Ada Clarice Gastaldi
- Department of Health Sciences, Graduate Program in Functional Performance, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, 14049-900, Brazil.
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Zhang Y, Shi H, Su A, Dai F, Wang X, Zhang Y, Zheng Y, Cai C, Wang X. Angle β combined with FeNO and FEV1/FVC% for the detection of asthma in school-aged children. J Asthma 2021; 59:746-754. [PMID: 33435766 DOI: 10.1080/02770903.2021.1874979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The diagnostic value of angle β in school-aged children with asthma is unknown. We speculate that angle β may reflect diversification of the forced expiratory flow (FEF) to some extent. The objective of this study was to assess the diagnostic accuracy of angle β, FeNO, pulmonary function parameters and their combinations for asthma in school-aged children. METHODS In total, 248 children participated in this study (140 children with asthma and 108 healthy children). The diagnostic performance of angle β, FeNO and pulmonary function parameters was determined using receiver operating characteristic (ROC) curves. In the ROC analysis, we used the hold out cross-validation method to avoid overfitting. This study was performed in China and followed the Guidelines for the diagnosis and optimal management of asthma in children (China). RESULTS 1) In the asthma group, the mean angle β value was significantly smaller than that in the control group (P < 0.001), but the mean FeNO value was significantly higher than that in the control group (P < 0.001). 2) More acute exacerbation or greater severity corresponded to a smaller angle β. 3) Among the single indices, the area under the ROC curve of angle β was the largest (except for FEV1/FVC%). For combined indicators, after cross-verification, the combination of angle β, FEV1/FVC% and FeNO showed the highest diagnostic accuracy. CONCLUSION Angle β combined with FeNO and FEV1/FVC% can improve the diagnostic accuracy for asthma in school-aged children.
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Affiliation(s)
- Yanli Zhang
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Hongke Shi
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Aifang Su
- Department of Pediatrics, Henan Province Luohe City Children's Hospital, Luohe, China
| | - Fuli Dai
- Department of Pediatrics, Henan Province Luoyang City Women and Children Medical Care Center, Luoyang, China
| | - Xiufang Wang
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Yan Zhang
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Yuehong Zheng
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Chunling Cai
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Xiao Wang
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
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Foy B, Kay D, Siddiqui S, Brightling C, Paiva M, Verbanck S. Increased ventilation heterogeneity in asthma can be attributed to proximal bronchioles. Eur Respir J 2020; 55:13993003.01345-2019. [PMID: 31806713 DOI: 10.1183/13993003.01345-2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 11/12/2019] [Indexed: 11/05/2022]
Affiliation(s)
- Brody Foy
- Center for Systems Biology and Dept of Pathology, Massachusetts General Hospital, Boston, MA, USA.,Dept of Systems Biology, Harvard Medical School, Boston, MA, USA
| | - David Kay
- Dept of Computer Science, University of Oxford, Oxford, UK
| | - Salman Siddiqui
- Dept of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Chris Brightling
- Dept of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Manuel Paiva
- Respiratory Division, University Hospital Erasme, Brussels, Belgium
| | - Sylvia Verbanck
- Respiratory Division, University Hospital UZBrussel, Brussels, Belgium
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Garcia-Marcos L, Edwards J, Kennington E, Aurora P, Baraldi E, Carraro S, Gappa M, Louis R, Moreno-Galdo A, Peroni DG, Pijnenburg M, Priftis KN, Sanchez-Solis M, Schuster A, Walker S. Priorities for future research into asthma diagnostic tools: A PAN-EU consensus exercise from the European asthma research innovation partnership (EARIP). Clin Exp Allergy 2019; 48:104-120. [PMID: 29290104 DOI: 10.1111/cea.13080] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The diagnosis of asthma is currently based on clinical history, physical examination and lung function, and to date, there are no accurate objective tests either to confirm the diagnosis or to discriminate between different types of asthma. This consensus exercise reviews the state of the art in asthma diagnosis to identify opportunities for future investment based on the likelihood of their successful development, potential for widespread adoption and their perceived impact on asthma patients. Using a two-stage e-Delphi process and a summarizing workshop, a group of European asthma experts including health professionals, researchers, people with asthma and industry representatives ranked the potential impact of research investment in each technique or tool for asthma diagnosis and monitoring. After a systematic review of the literature, 21 statements were extracted and were subject of the two-stage Delphi process. Eleven statements were scored 3 or more and were further discussed and ranked in a face-to-face workshop. The three most important diagnostic/predictive tools ranked were as follows: "New biological markers of asthma (eg genomics, proteomics and metabolomics) as a tool for diagnosis and/or monitoring," "Prediction of future asthma in preschool children with reasonable accuracy" and "Tools to measure volatile organic compounds (VOCs) in exhaled breath."
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Affiliation(s)
- L Garcia-Marcos
- Respiratory and Allergy Units, Arrixaca University Children's Hospital, University of Murcia & IMIB Research Institute, Murcia, Spain
| | | | | | - P Aurora
- Department of Paediatric Respiratory Medicine, Great Ormond Street Hospital for Children, London, UK.,Department of Respiratory, Critical Care and Anaesthesia Unit, University College London (UCL) Great Ormond Street Institute of Child Health, London, UK
| | - E Baraldi
- Women's and Children's Health Department, University of Padua, Padova, Italy
| | - S Carraro
- Women's and Children's Health Department, University of Padua, Padova, Italy
| | - M Gappa
- Children's Hospital & Research Institute, Marienhospital Wesel, Wesel, Germany
| | - R Louis
- Department of Respiratory Medicine, University of Liege, Liege, Belgium
| | - A Moreno-Galdo
- Paediatric Pulmonology Unit, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - D G Peroni
- Department of Clinical and Experimental Medicine, Section of Paediatrics, University of Pisa, Pisa, Italy
| | - M Pijnenburg
- Paediatrics/Paediatric Respiratory Medicine, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - K N Priftis
- Department of Paediatrics, Athens University Medical School, Attikon General Hospital, Athens, Greece
| | - M Sanchez-Solis
- Respiratory and Allergy Units, Arrixaca University Children's Hospital, University of Murcia & IMIB Research Institute, Murcia, Spain
| | - A Schuster
- Department of Paediatrics, University Hospital, Düsseldorf, Germany
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7
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Kuo CR, Jabbal S, Anderson W, Lipworth BJ. Pragmatic evaluation of inhaled corticosteroid particle size formulations on asthma control. Clin Exp Allergy 2019; 49:1321-1327. [PMID: 31264282 DOI: 10.1111/cea.13453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/07/2019] [Accepted: 06/26/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND Extra-fine particle formulations of inhaled corticosteroid (ICS) are associated with improved lung delivery. OBJECTIVES A pragmatic study to assess patient-reported outcomes after switching from fine to extra-fine particle ICS in persistent asthma. METHODS Twenty-four patients (mean age 48 year, FEV1 84%, ACQ 1.67) received 4 weeks run-in with a constant dose of fine particle ICS (mean dose 710 µg), followed by switching to an equivalent dose of extra-fine particle hydrofluoroalkane beclomethasone dipropionate (mean dose 355µg). Asthma control questionnaire (ACQ), the primary outcome and mini asthma quality of life questionnaire (mAQLQ) were measured pre- and post-run-in (baseline) and after 4 weeks and 8 weeks of switching. RESULTS Comparing pre- vs post-run-in, there were no differences for ACQ: 1.67 vs 1.65 or AQLQ: 5.08 vs 5.34. There were mean (95%CI) improvements (P < 0.001) from baseline after 8 weeks for ACQ: -0.53 (-0.83, -0.23) and AQLQ: 0.69 (0.35, 1.04), which exceeded the minimal clinically important difference (MCID) of 0.5 for both. There were also differences (P < 0.05) in domiciliary symptoms and reliever use. There were no significant changes at 8 weeks in lung function, FeNO or blood eosinophils. CONCLUSIONS Pragmatic switching from fine to extra-fine particle ICS at half the dose was associated with clinically relevant improvements in asthma control and quality of life, but not lung function or type 2 biomarkers.
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Affiliation(s)
- Chris RuiWen Kuo
- Scottish Centre for Respiratory Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Sunny Jabbal
- Scottish Centre for Respiratory Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - William Anderson
- Scottish Centre for Respiratory Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
| | - Brian J Lipworth
- Scottish Centre for Respiratory Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK
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Karvonen T, Lehtimäki L. Flow-independent nitric oxide parameters in asthma: a systematic review and meta-analysis. J Breath Res 2019; 13:044001. [PMID: 31239409 DOI: 10.1088/1752-7163/ab2c99] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Fractional exhaled nitric oxide (FENO) has been proposed as a non-invasive marker of inflammation in the lungs. Measuring FENO at several flow rates enables the calculation of flow independent NO-parameters that describe the NO-exchange dynamics of the lungs more precisely. The purpose of this study was to compare the NO-parameters between asthmatics and healthy subjects in a systematic review and meta-analysis. METHODS A systematic search was performed in Ovid Medline, Web of Science, Scopus and Cochrane Library databases. All studies with asthmatic and healthy control groups with at least one NO-parameter calculated were included. RESULTS From 1137 identified studies, 33 were included in the meta-analysis. All NO-parameters (alveolar NO concentration (CANO), bronchial flux of NO (JawNO), bronchial mucosal NO concentration (CawNO) and bronchial wall NO diffusion capacity (DawNO)) were found increased in glucocorticoid-treated and glucocorticoid-naïve asthma. JawNO and CANO were most notably increased in both study groups. Elevation of DawNO and CawNO seemed less prominent in both asthma groups. DISCUSSION We found that all the NO-parameters are elevated in asthma as compared to healthy subjects. However, results were highly heterogenous and the evidence on CawNO and DawNO is still quite feeble due to only few studies reporting them. To gain more knowledge on the NO-parameters in asthma, nonlinear methods and standardized study protocols should be used in future studies.
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Affiliation(s)
- Tuomas Karvonen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
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Zhu H, Zhang R, Hao C, Yu X, Tian Z, Yuan Y. Fractional Exhaled Nitric Oxide (FeNO) Combined with Pulmonary Function Parameters Shows Increased Sensitivity and Specificity for the Diagnosis of Cough Variant Asthma in Children. Med Sci Monit 2019; 25:3832-3838. [PMID: 31120043 PMCID: PMC6543875 DOI: 10.12659/msm.913761] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background Cough variant asthma in children presents with a dry nonproductive cough. This study aimed to investigate the diagnostic value of fractional exhaled nitric oxide (FeNO) combined with small airway functional parameters in cough variant asthma. Material/Methods Children with asthma (n=136) were divided into a cough variant asthma (CVA) group (n=57; mean age, 8.03±2.1 years) and a non-cough variant asthma (nCVA) group (n=79; mean age, 8.61±1.7 years). In both groups, FeNO and other pulmonary function parameters were measured including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), maximum mid-expiratory flow (MMEF), forced expiratory flow (FEF), and maximum expiratory flow at 25%, 50%, and 75% expired volume (MEF25, MEF50, and MEF75). Receiver-operating characteristic (ROC) curve analysis compared the sensitivity and specificity between the diagnostic parameters. Results The FeNO values were significantly increased in the CVA group compared with the nCVA group (Z=6.890, p<0.001). The MMEF, MEF25, MEF50, and MEF75 values were significantly lower in the CVA group compared with the nCVA group (p=0.000, p=0.014, p=0.000, and p=0.000, respectively). The FeNO values were negatively correlated with MEF25, MEF50, and MMEF (r=−0.334, r=−0.257 and r=−0.276, respectively). FeNO was significantly more efficient diagnosing cough variant asthma comparing with pulmonary parameters (p<0.05), and was most sensitive and specific when combined with MMEF/MEF50 compared with single diagnostic parameters (p<0.05). Conclusions FeNO combined with pulmonary function parameters of MMEF/MEF50 showed increased sensitivity and specificity for the diagnosis of cough variant asthma.
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Affiliation(s)
- Haiyan Zhu
- Department of Pediatrics, The Affiliated Huaian No.1 Peoples' Hospital of Nanjing Medical University, Huai'an, Jiangsu, China (mainland)
| | - Rongrong Zhang
- Department of Pediatrics, The Affiliated Huaian No.1 Peoples' Hospital of Nanjing Medical University, Huai'an, Jiangsu, China (mainland)
| | - Chuangli Hao
- Department of Respiratory Diseases, Childrens' Hospital of Soochow University, Suzhou, Jiangsu, China (mainland)
| | - Xingmei Yu
- Department of Respiratory Diseases, Childrens' Hospital of Soochow University, Suzhou, Jiangsu, China (mainland)
| | - Zhaofang Tian
- Department of Pediatrics, The Affiliated Huaian No.1 Peoples' Hospital of Nanjing Medical University, Huai'an, Jiangsu, China (mainland)
| | - Yufang Yuan
- Department of Pediatrics, The Affiliated Huaian No.1 Peoples' Hospital of Nanjing Medical University, Huai'an, Jiangsu, China (mainland)
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10
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Petousi N, Talbot NP, Pavord I, Robbins PA. Measuring lung function in airways diseases: current and emerging techniques. Thorax 2019; 74:797-805. [PMID: 31036773 DOI: 10.1136/thoraxjnl-2018-212441] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 02/14/2019] [Accepted: 02/25/2019] [Indexed: 12/12/2022]
Abstract
Chronic airways diseases, including asthma, COPD and cystic fibrosis, cause significant morbidity and mortality and are associated with high healthcare expenditure, in the UK and worldwide. For patients with these conditions, improvements in clinical outcomes are likely to depend on the application of precision medicine, that is, the matching of the right treatment to the right patient at the right time. In this context, the identification and targeting of 'treatable traits' is an important priority in airways disease, both to ensure the appropriate use of existing treatments and to facilitate the development of new disease-modifying therapy. This requires not only better understanding of airway pathophysiology but also an enhanced ability to make physiological measurements of disease activity and lung function and, if we are to impact on the natural history of these diseases, reliable measures in early disease. In this article, we outline some of the key challenges faced by the respiratory community in the management of airways diseases, including early diagnosis, disease stratification and monitoring of therapeutic response. In this context, we review the advantages and limitations of routine physiological measurements of respiratory function including spirometry, body plethysmography and diffusing capacity and discuss less widely used methods such as forced oscillometry, inert gas washout and the multiple inert gas elimination technique. Finally, we highlight emerging technologies including imaging methods such as quantitative CT and hyperpolarised gas MRI as well as quantification of lung inhomogeneity using precise in-airway gas analysis and mathematical modelling. These emerging techniques have the potential to enhance existing measures in the assessment of airways diseases, may be particularly valuable in early disease, and should facilitate the efforts to deliver precision respiratory medicine.
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Affiliation(s)
- Nayia Petousi
- Nuffield Department of Clinical Medicine Division of Experimental Medicine, University of Oxford, Oxford, UK .,Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.,Oxford Centre for Respiratory Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Nick P Talbot
- Nuffield Department of Clinical Medicine Division of Experimental Medicine, University of Oxford, Oxford, UK.,Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.,Oxford Centre for Respiratory Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Ian Pavord
- Nuffield Department of Clinical Medicine Division of Experimental Medicine, University of Oxford, Oxford, UK.,Oxford Centre for Respiratory Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Peter A Robbins
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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Postma DS, Brightling C, Baldi S, Van den Berge M, Fabbri LM, Gagnatelli A, Papi A, Van der Molen T, Rabe KF, Siddiqui S, Singh D, Nicolini G, Kraft M. Exploring the relevance and extent of small airways dysfunction in asthma (ATLANTIS): baseline data from a prospective cohort study. THE LANCET RESPIRATORY MEDICINE 2019; 7:402-416. [PMID: 30876830 DOI: 10.1016/s2213-2600(19)30049-9] [Citation(s) in RCA: 195] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/26/2018] [Accepted: 12/18/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Small airways dysfunction (SAD) is well recognised in asthma, yet its role in the severity and control of asthma is unclear. This study aimed to assess which combination of biomarkers, physiological tests, and imaging markers best measure the presence and extent of SAD in patients with asthma. METHODS In this baseline assessment of a multinational prospective cohort study (the Assessment of Small Airways Involvement in Asthma [ATLANTIS] study), we recruited participants with and without asthma (defined as Global Initiative for Asthma severity stages 1-5) from general practices, the databases of chest physicians, and advertisements at 29 centres across nine countries (Brazil, China, Germany, Italy, Spain, the Netherlands, the UK, the USA, and Canada). All participants were aged 18-65 years, and participants with asthma had received a clinical diagnosis of asthma more than 6 months ago that had been confirmed by a chest physician. This diagnosis required support by objective evidence at baseline or during the past 5 years, which could be: positive airway hyperresponsiveness to methacholine, positive reversibility (a change in FEV1 ≥12% and ≥200 mL within 30 min) after treatment with 400 μg of salbutamol in a metered-dose inhaler with or without a spacer, variability in peak expiratory flow of more than 20% (measured over 7 days), or documented reversibility after a cycle (eg, 4 weeks) of maintenance anti-asthma treatment. The inclusion criteria also required that patients had stable asthma on any previous regular asthma treatment (including so-called rescue β2-agonists alone) at a stable dose for more than 8 weeks before baseline and had smoked for a maximum of 10 pack-years in their lifetime. Control group participants were recruited by advertisements; these participants were aged 18-65 years, had no respiratory symptoms compatible with asthma or chronic obstructive pulmonary disease, normal spirometry, and normal airways responsiveness, and had smoked for a maximum of 10 pack-years. We assessed all participants with spirometry, body plethysmography, impulse oscillometry, multiple breath nitrogen washout, CT (in selected participants), and questionnaires about asthma control, asthma-related quality of life (both in participants with asthma only), and health status. We applied structural equation modelling in participants with asthma to assess the contribution of all physiological and CT variables to SAD, from which we defined clinical SAD and CT SAD scores. We then classified patients with asthma into SAD groups with model-based clustering, and we compared asthma severity, control, and health-care use during the past year by SAD score and by SAD group. This trial is registered with ClinicalTrials.gov, number NCT02123667. FINDINGS Between June 30, 2014, and March 3, 2017, we recruited and evaluated 773 participants with asthma and 99 control participants. All physiological measures contributed to the clinical SAD model with the structural equation modelling analysis. The prevalence of SAD in asthma was dependent on the measure used; we found the lowest prevalence of SAD associated with acinar airway ventilation heterogeneity (Sacin), an outcome determined by multiple breath nitrogen washout that reflects ventilation heterogeneity in the most peripheral, pre-acinar or acinar airways. Impulse oscillometry and spirometry results, which were used to assess dysfunction of small-sized to mid-sized airways, contributed most to the clinical SAD score and differed between the two SAD groups. Participants in clinical SAD group 1 (n=452) had milder SAD than group 2 and comparable multiple breath nitrogen washout Sacin to control participants. Participants in clinical SAD group 2 (n=312) had abnormal physiological SAD results relative to group 1, particularly their impulse oscillometry and spirometry measurements, and group 2 participants also had more severe asthma (with regard to asthma control, treatments, exacerbations, and quality of life) than group 1. Clinical SAD scores were higher (indicating more severe SAD) in group 2 than group 1, and we found that these scores were related to asthma control, severity, and exacerbations. We found no correlation between clinical SAD and CT SAD scores. INTERPRETATION SAD is a complex and silent signature of asthma that is likely to be directly or indirectly captured by combinations of physiological tests, such as spirometry, body plethysmography, impulse oscillometry, and multiple breath nitrogen washout. SAD is present across patients with all severities of asthma, but it is particularly prevalent in severe disease. The clinical classification of SAD into two groups (a milder and a more severe group) by use of impulse oscillometry and spirometry, which are easy to use, is meaningful given its association with GINA severity stages, asthma control, quality of life, and exacerbations. FUNDING Chiesi Farmaceutici SpA.
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Affiliation(s)
- Dirkje S Postma
- Department of Pulmonology, Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
| | - Chris Brightling
- Institute for Lung Health, National Institute for Health Research Biomedical Research Centre, University of Leicester, Leicester, UK
| | - Simonetta Baldi
- Institute for Lung Health, National Institute for Health Research Biomedical Research Centre, University of Leicester, Leicester, UK; Department of Global Clinical Development, Chiesi SAS, Bois-Colombes, France
| | - Maarten Van den Berge
- Department of Pulmonology, Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Leonardo M Fabbri
- Research Centre on Asthma and COPD, University of Ferrara, Ferrara, Italy; COPD Centre, Sahlgrenska University Hospital, Gothenburg, Sweden
| | | | - Alberto Papi
- Research Centre on Asthma and COPD, University of Ferrara, Ferrara, Italy
| | - Thys Van der Molen
- Department of General Practice, Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Klaus F Rabe
- LungenClinic, Grosshansdorf, Germany; Department of Medicine, Christian Albrechts University, Kiel, Germany; Airway Research Center North, German Center for Lung Research (DZL), Hannover, Germany
| | - Salman Siddiqui
- Institute for Lung Health, National Institute for Health Research Biomedical Research Centre, University of Leicester, Leicester, UK
| | - Dave Singh
- Centre for Respiratory Medicine and Allergy, University Hospital of South Manchester, University of Manchester, Manchester, UK
| | - Gabriele Nicolini
- Department of Global Clinical Development, Chiesi Farmaceutici SpA, Parma, Italy
| | - Monica Kraft
- University of Arizona College of Medicine, Department of Medicine, Tucson, AZ, USA
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12
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Farah CS, Badal T, Reed N, Rogers PG, King GG, Thamrin C, Peters MJ, Seccombe LM. Mepolizumab improves small airway function in severe eosinophilic asthma. Respir Med 2019; 148:49-53. [PMID: 30827474 DOI: 10.1016/j.rmed.2019.01.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/19/2019] [Accepted: 01/22/2019] [Indexed: 10/27/2022]
Abstract
BACKGROUND AND OBJECTIVE Treatment with mepolizumab in severe eosinophilic asthma (SEA) significantly reduces exacerbations with modest improvements in symptom control and spirometry. The time course of any changes in small airway function is unknown. OBJECTIVE To describe changes in ventilation inhomogeneity, a marker of small airway function, after commencing mepolizumab. METHODS Prospective cohort of 20 adults (12 male) with SEA commencing monthly mepolizumab. Measurements at baseline, Week 4 and Week 26 included the Asthma Control Questionnaire (ACQ-5), spirometry, fraction of exhaled nitric oxide (FeNO) and multiple breath nitrogen washout to measure global (Lung Clearance Index, [LCI]) and regional ventilation inhomogeneity in acinar (Sacin) and conducting (Scond) airways. Other asthma therapy remained unchanged between baseline and Week 4. Treatment related changes were assessed using RM-ANOVA and paired t-tests. Relationships between changes in lung function and symptoms were assessed by Pearson's correlation. RESULTS At Week 4, ACQ-5, spirometry, LCI and Sacin improved significantly (p < 0.04) and all were sustained at Week 26. The change in ACQ-5 correlated with the change in Sacin (r = 0.48, p = 0.03) and FRC (r = 0.46, p = 0.04), but not spirometry. CONCLUSION Improved symptom control improved rapidly after commencing mepolizumab in patients with SEA. The early improvement in small airway function was associated with asthma control and may be a significant contributor to the therapeutic response.
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Affiliation(s)
- Claude S Farah
- Department of Thoracic Medicine, Concord Hospital, Sydney, Australia; The Woolcock Institute of Medical Research, NSW, Australia; Faculty of Medicine and Health, Sydney University, Australia; Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia.
| | - Tanya Badal
- Department of Thoracic Medicine, Concord Hospital, Sydney, Australia; The Woolcock Institute of Medical Research, NSW, Australia
| | - Nicola Reed
- Department of Thoracic Medicine, Concord Hospital, Sydney, Australia
| | - Peter G Rogers
- Department of Thoracic Medicine, Concord Hospital, Sydney, Australia
| | - Gregory G King
- The Woolcock Institute of Medical Research, NSW, Australia; Faculty of Medicine and Health, Sydney University, Australia
| | - Cindy Thamrin
- The Woolcock Institute of Medical Research, NSW, Australia; Faculty of Medicine and Health, Sydney University, Australia
| | - Matthew J Peters
- Department of Thoracic Medicine, Concord Hospital, Sydney, Australia; Faculty of Medicine and Health, Sydney University, Australia; Faculty of Medicine and Health Sciences, Macquarie University, NSW, Australia
| | - Leigh M Seccombe
- Department of Thoracic Medicine, Concord Hospital, Sydney, Australia; Faculty of Medicine and Health, Sydney University, Australia
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13
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Chanez P, Pahus L, Charriot J, Bourdin A. Severe asthma treated by bronchial thermoplasty: A success not due to the small airways? Respirology 2019; 24:402-403. [PMID: 30694006 DOI: 10.1111/resp.13481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 01/08/2019] [Indexed: 01/30/2023]
Affiliation(s)
- Pascal Chanez
- Aix Marseille Univ, APHM, Clinique des bronches allergies et sommeil, Marseille, France.,Aix Marseille Univ, INSERM U1263, INRA 1260 (C2VN), Marseille, France
| | - Laurie Pahus
- Aix Marseille Univ, APHM, Clinique des bronches allergies et sommeil, Marseille, France.,Aix Marseille Univ, INSERM U1263, INRA 1260 (C2VN), Marseille, France.,Aix Marseille Univ, CNRS, EFS, ADES, Marseille, France
| | - Jeremy Charriot
- Université de Montpellier, PhyMedExp, INSERM, CNRS, CHU de Montpellier, Department of Respiratory Diseases, Montpellier, France
| | - Arnaud Bourdin
- Université de Montpellier, PhyMedExp, INSERM, CNRS, CHU de Montpellier, Department of Respiratory Diseases, Montpellier, France
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14
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Aldakheel FM, Bourke JE, Thomas PS, Matheson MC, Abramson MJ, Hamilton GS, Lodge CJ, Thompson BR, Walters EH, Allen KJ, Erbas B, Perret JL, Dharmage SC, Lowe AJ. NO x in exhaled breath condensate is related to allergic sensitization in young and middle-aged adults. Clin Exp Allergy 2018; 49:171-179. [PMID: 30107057 DOI: 10.1111/cea.13251] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 07/27/2018] [Accepted: 07/29/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND Asthma and allergic diseases are heterogeneous. Measurement of biomarkers in exhaled breath condensate (EBC) may help to discriminate between different phenotypes and may assist with clinical prognostication. OBJECTIVES We aimed to assess associations between total nitric oxide products (NOx ) in EBC and different allergic phenotypes and lung function in young and middle-aged adults. METHODS Cross-sectional analyses were nested within two Australian longitudinal studies, the Melbourne Atopy Cohort Study (MACS, mean age 17.8 years) and the Tasmanian Longitudinal Health Study (TAHS, mean age 49.4 years). Levels of EBC NOx were determined by Griess-reaction fluorescent method. Associations were assessed between EBC NOx and different allergic phenotypes, lung function and airway reactivity. RESULTS Atopy, with or without asthma or rhinitis, was associated with increased EBC NOx levels particularly in individuals with poly-aero-sensitization. These findings were generally consistent across the two age groups. In the older cohort, use of ICS in the previous 12 months masked the association between sensitization and EBC NOx (OR = 0.64, 95% CI = 0.21-1.96, p for interaction = 0.05). CONCLUSIONS AND CLINICAL RELEVANCE In these population-based samples, EBC NOx was most strongly associated with atopic sensitization, rather than either current asthma or rhinitis, possibly indicating underlying increased airway inflammation associated with atopy. Therefore, EBC NOx could be a key predictor of atopy in both young and middle-aged adults, regardless of the presence of concomitant asthma or rhinitis.
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Affiliation(s)
- Fahad M Aldakheel
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Jane E Bourke
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, Vic., Australia
| | - Paul S Thomas
- Department of Respiratory Medicine & Prince of Wales Hospital Clinical School, University of New South Wales, Kensington, NSW, Australia
| | - Melanie C Matheson
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Vic., Australia.,Murdoch Children's Research Institute, Melbourne, Vic., Australia
| | - Michael J Abramson
- School of Public Health & Preventive Medicine, Monash University, Melbourne, Vic., Australia
| | - Garun S Hamilton
- School of Clinical Sciences, Monash University, Melbourne, Vic., Australia.,Monash Lung and Sleep, Monash Health, Melbourne, Vic., Australia
| | - Caroline J Lodge
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Vic., Australia.,Murdoch Children's Research Institute, Melbourne, Vic., Australia
| | - Bruce R Thompson
- Allergy, Immunology and Respiratory Medicine, the Alfred Hospital, Melbourne, Vic., Australia.,Central Clinical School, Monash University, Melbourne, Vic., Australia
| | - E Haydn Walters
- School of Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Katrina J Allen
- Murdoch Children's Research Institute, Melbourne, Vic., Australia
| | - Bircan Erbas
- School of Public Health, La Trobe University, Melbourne, Vic., Australia
| | - Jennifer L Perret
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Vic., Australia.,Centre for Air quality and health Research and evaluation (CAR), Melbourne, Vic., Australia
| | - Shyamali C Dharmage
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Vic., Australia.,Murdoch Children's Research Institute, Melbourne, Vic., Australia
| | - Adrian J Lowe
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Vic., Australia.,Murdoch Children's Research Institute, Melbourne, Vic., Australia
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15
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Tirakitsoontorn P, Crookes M, Fregeau W, Pabelonio N, Morphew T, Shin HW, Galant SP. Recognition of the peripheral airway impairment phenotype in children with well-controlled asthma. Ann Allergy Asthma Immunol 2018; 121:692-698. [PMID: 30194972 DOI: 10.1016/j.anai.2018.08.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/28/2018] [Accepted: 08/31/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Peripheral airway impairment, although frequently unrecognized, is a risk factor for poor asthma control, loss of control, increased exacerbations, airway hyperresponsiveness, and loss of lung function with age, even in patients with well-controlled asthma. OBJECTIVE To determine the presence of peripheral airway impairment by impulse oscillometry and forced expiratory flow between 25% and 75% (FEF25%-75%) in children whose asthma is well controlled by National Asthma Education and Prevention Program (NAEPP) guidelines. METHODS In this retrospective, cross-sectional analysis, outcomes were evaluated across 192 encounters in 139 patients with moderate to severe asthma, ages 4-18 years. Receiver operator characteristic curves were created and oscillometry thresholds determined by maximizing the sum of sensitivity and specificity to identify those whose condition is not well controlled. Impairment was then identified for those whose condition was well controlled when these age-dependent oscillometry thresholds were met for each IOS measure or FEF25%-75% < 65% of predicted. RESULTS Reactance at 5 Hz (X5) appeared most robust to identify peripheral airway impairment. In 96 well-controlled asthma encounters, impairment was identified by X5 in approximately 20% and 45% for those younger than 12 years and adolescents, respectively, compared with a maximum of 10% with FEF25%-75% in the adolescent cohort (P < .05). CONCLUSION We conclude that peripheral airway impairment, determined by oscillometry, is common in patients with well-controlled asthma across age cohorts. X5 with optimal cut points ≤ -3.8, ≤ -2.5, and ≤ -1.5 cmH2O/L/s for ages 4-7, 8-11, and >12 years, provides the clinician with a practical tool to identify the presence of the peripheral airway impairment phenotype that is consistently superior to FEF25%-75%. This recognition, if confirmed, may reduce the risk of asthma-associated consequences with earlier and more targeted therapy.
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Affiliation(s)
- Pornchai Tirakitsoontorn
- Pulmonology Division, Children's Hospital of Orange County, Orange, California; Department of Pediatrics, University of California Irvine, Irvine, California.
| | - Maisie Crookes
- Pulmonology Division, Children's Hospital of Orange County, Orange, California
| | - William Fregeau
- Department of Cardiopulmonary Service, Children's Hospital of Orange County, Orange, California
| | - Neil Pabelonio
- Department of Cardiopulmonary Service, Children's Hospital of Orange County, Orange, California
| | | | - Hye-Won Shin
- Chiron Total & KSK Research Institute, Irvine, California
| | - Stanley P Galant
- Department of Pediatrics, University of California Irvine, Irvine, California; CHOC Breathmobile, Children's Hospital of Orange County, Orange, California
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16
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Stockley JA, Cooper BG, Stockley RA, Sapey E. Small airways disease: time for a revisit? Int J Chron Obstruct Pulmon Dis 2017; 12:2343-2353. [PMID: 28848335 PMCID: PMC5557120 DOI: 10.2147/copd.s138540] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
It is increasingly acknowledged that delays in the diagnosis of chronic inflammatory lung conditions have hampered our understanding of pathogenesis and thus our ability to design efficacious therapies. This is particularly true for COPD, where most patients are diagnosed with moderate-to-severe airflow obstruction and little is known about the inflammatory processes present in early disease. There is great interest in developing screening tests that can identify those most at risk of developing COPD before airflow obstruction has developed for the purpose of research and clinical care. Landmark pathology studies have suggested that damage to the small airways precedes the development of airflow obstruction and emphysema and, thus, presents an opportunity to identify those at risk of COPD. However, despite a number of physiological tests being available to assess small airways function, none have been adopted into routine care in COPD. The reasons that tests of small airways have not been utilized widely include variability in test results and a lack of validated reference ranges from which to compare results for some methodologies. Furthermore, population studies have not consistently demonstrated their ability to diagnose disease. However, the landscape may be changing. As the equipment that delivers tests of small airways become more widely available, reference ranges are emerging and newer methodologies specifically seek to address variability and difficulty in test performance. Moreover, there is evidence that while tests of small airways may not be helpful across the full range of established disease severity, there may be specific groups (particularly those with early disease) where they might be informative. In this review, commonly utilized tests of small airways are critically appraised to highlight why these tests may be important, how they can be used and what knowledge gaps remain for their use in COPD.
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Affiliation(s)
| | | | | | - Elizabeth Sapey
- Institute of Inflammation and Ageing, Centre for Translational Inflammation Research, University of Birmingham, Edgbaston, Birmingham, UK
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17
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Steinbacher M, Pfleger A, Schwantzer G, Jauk S, Weinhandl E, Eber E. Small airway function before and after cold dry air challenge in pediatric asthma patients during remission. Pediatr Pulmonol 2017; 52:873-879. [PMID: 28486753 DOI: 10.1002/ppul.23724] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 04/12/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND We wanted to compare cold dry air challenge (CACh) induced changes in spirometric parameters with changes in nitrogen multiple breath washout (N2 MBW) parameters in pediatric asthma patients during clinical remission over the past year (ie, with "inactive asthma"). As N2 MBW assesses ventilation heterogeneity we expected to gain detailed information about peripheral airways contribution. METHODS In subjects with normal spirometry N2 MBW, spirometry and body plethysmography were performed at baseline, after CACh, and after salbutamol inhalation. An initial measurement of the fraction of exhaled nitric oxide (FeNO) was conducted. RESULTS Forty-three (20 female) subjects, mean age 13.7 years (range 6.5-18.6) performed reproducible N2 MBW measurements. Ten were tested hyperresponsive (23.3%) and 33 normoresponsive (76.7%). Baseline spirometry and body plethysmography as well as FRC (N2 MBW) were similar in both groups. Scond (0.031 vs 0.022), Sacin (0.057 vs 0.067), and FeNO (92.0 vs 28.5 ppb) were not statistically different between hyperresponsive and nomoresponsive subjects at baseline. Subjects with airway hyperresponsiveness (AHR) showed significant increases in lung clearance index (LCI, P = 0.011) and Scond (P = 0.008) after CACh, and significant decreases after salbutamol (LCI: P = 0.005; Scond: P = 0.005). In contrast, normoresponsive subjects showed no relevant changes after CACh, and only a decrease of Scond after salbutamol (P = 0.007). There were significant correlations between the CACh induced changes in FEV1 and changes in LCI (r = -0.45, P = 0.003), Scond (r = -0.30, P = 0.047), and Sacin (r = -0.47, P = 0.008), respectively. CONCLUSION Our study provides evidence of small airway involvement in children and adolescents with inactive asthma and airway hyperresponsiveness.
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Affiliation(s)
- Michael Steinbacher
- Division of Pediatric Pulmonology and Allergology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Andreas Pfleger
- Division of Pediatric Pulmonology and Allergology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Gerold Schwantzer
- Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria
| | - Stefanie Jauk
- Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria
| | - Elisabeth Weinhandl
- Division of Pediatric Pulmonology and Allergology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Ernst Eber
- Division of Pediatric Pulmonology and Allergology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
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18
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Postma DS, Brightling C, Fabbri L, van der Molen T, Nicolini G, Papi A, Rabe KF, Siddiqui S, Singh D, van den Berge M, Kraft M. Unmet needs for the assessment of small airways dysfunction in asthma: introduction to the ATLANTIS study. Eur Respir J 2016; 45:1534-8. [PMID: 26028618 DOI: 10.1183/09031936.00214314] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Dirkje S Postma
- University of Groningen, University Medical Center Groningen, Dept of Pulmonology, Groningen, The Netherlands
| | - Chris Brightling
- Dept of Infection, Immunity and Inflammation, Institute for Lung Health, University of Leicester, Leicester, UK
| | - Leo Fabbri
- Dept of Oncology Haematology and Respiratory Disease, University of Modena and Reggio Emilia, Modena, Italy
| | - Thys van der Molen
- University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Gabriele Nicolini
- Global Clinical Development, Chiesi Farmaceutici S.p.A., Parma, Italy
| | - Alberto Papi
- Dept of Respiratory Medicine, University of Ferrara, Ferrara, Italy
| | - Klaus F Rabe
- Dept of Medicine, Christian Albrechts University Kiel, Kiel and LungenClinic Grosshansdorf, Grosshansdorf, Germany (Members of the German Center for Lung Research (DZL))
| | - Salman Siddiqui
- Dept of Infection, Immunity and Inflammation, Respiratory Biomedical Research Unit, Glenfield Hospital, Leicester, UK
| | - Dave Singh
- Medicines Evaluation Unit, University Hospital of South Manchester Foundation Trust, University of Manchester, Manchester, UK
| | - Maarten van den Berge
- University of Groningen, University Medical Center Groningen, Dept of Pulmonology, Groningen, The Netherlands
| | - Monica Kraft
- Dept of Medicine, University of Arizona Health Sciences Center, Tucson, AZ, USA
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Kee K, Stuart-Andrews C, Nilsen K, Wrobel JP, Thompson BR, Naughton MT. Ventilation heterogeneity is increased in patients with chronic heart failure. Physiol Rep 2015; 3:3/10/e12590. [PMID: 26493954 PMCID: PMC4632958 DOI: 10.14814/phy2.12590] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In the healthy lung, ventilation is distributed heterogeneously due to factors such as anatomical asymmetry and gravity. This ventilation heterogeneity increases pathologically in conditions such as asthma, chronic obstructive lung disease, and cystic fibrosis. In chronic heart failure, lung biopsy demonstrates evidence of peripheral lung fibrosis and small airways narrowing and distortion. We hypothesized that this would lead to increased ventilation heterogeneity. Furthermore, we proposed that rostral fluid shifts when seated patients lie supine would further increase ventilation heterogeneity. We recruited 30 ambulatory chronic heart failure patients (57 ± 10 years, 83% male, left ventricular ejection fraction 31 ± 12%) as well as 10 healthy controls (51 ± 13 years, 90% male). Heart failure patients were clinically euvolemic. Subjects underwent measurement of ventilation heterogeneity using the multiple-breath nitrogen washout technique in the seated position, followed by repeat measurements after 5 and 45 min in the supine position. Ventilation heterogeneity was calculated using the lung clearance index (LCI), Sacin and Scond which represent overall, acinar, and small conducting airway function, respectively. Lung clearance index (9.6 ± 1.2 vs. 8.6 ± 1.4 lung turnovers, P = 0.034) and Scond (0.029 ± 0.014 vs. 0.006 ± 0.016/L, P = 0.007) were higher in the heart failure patients. There was no difference in Sacin (0.197 ± 0.171 vs. 0.125 ± 0.081/L, P = 0.214). Measures of ventilation heterogeneity did not change in the supine position. This study confirms the presence of peripheral airway pathology in patients with chronic heart failure. This leads to subtle but detectable functional abnormalities which do not change after 45 min in the supine position.
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Affiliation(s)
- Kirk Kee
- Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia Department of Allergy, Immunology and Respiratory Medicine, Melbourne, Australia
| | | | - Kris Nilsen
- Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia Department of Allergy, Immunology and Respiratory Medicine, Melbourne, Australia
| | - Jeremy P Wrobel
- Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia Department of Allergy, Immunology and Respiratory Medicine, Melbourne, Australia
| | - Bruce R Thompson
- Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia Department of Allergy, Immunology and Respiratory Medicine, Melbourne, Australia
| | - Matthew T Naughton
- Department of Medicine, Central Clinical School, Monash University, Melbourne, Australia Department of Allergy, Immunology and Respiratory Medicine, Melbourne, Australia
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20
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Lipworth B, Manoharan A, Anderson W. Unlocking the quiet zone: the small airway asthma phenotype. THE LANCET RESPIRATORY MEDICINE 2015; 2:497-506. [PMID: 24899370 DOI: 10.1016/s2213-2600(14)70103-1] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The small airways in the distal lung have been called the quiet zone because they are difficult to assess and treat in patients with asthma who have disproportionate impairment of small airway function. Evidence is accumulating to support a distinct clinical phenotype for patients with asthma who have impaired small airway function. The small airway asthma phenotype, which is prevalent in patients at all steps of management guidelines, seems to be associated with poor disease control. Alternatively, small airway dysfunction might be a sensitive indicator of early disease rather than a phenotype. Conventional coarse-particle inhalers, which emit particles larger than 2 μm, might not address persistent small airway dysfunction in patients with asthma. To target the entire lung with extra-fine particle formulations (smaller than 2 μm) of inhaled corticosteroids alone or in combination with long-acting β-agonists might result in improved long-term asthma control along with a commensurate improvement in small airway function. Prospective randomised controlled trials with extra-fine-particle inhaled drugs are now needed for patients with the small airway asthma phenotype.
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Affiliation(s)
- Brian Lipworth
- Scottish Centre for Respiratory Research, Ninewells Hospital and Medical School, Dundee, UK.
| | - Arvind Manoharan
- Scottish Centre for Respiratory Research, Ninewells Hospital and Medical School, Dundee, UK
| | - William Anderson
- Scottish Centre for Respiratory Research, Ninewells Hospital and Medical School, Dundee, UK
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McNulty W, Usmani OS. Techniques of assessing small airways dysfunction. Eur Clin Respir J 2014; 1:25898. [PMID: 26557240 PMCID: PMC4629724 DOI: 10.3402/ecrj.v1.25898] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 09/11/2014] [Indexed: 11/17/2022] Open
Abstract
The small airways are defined as those less than 2 mm in diameter. They are a major site of pathology in many lung diseases, not least chronic obstructive pulmonary disease (COPD) and asthma. The small airways are frequently involved early in the course of these diseases, with significant pathology demonstrable often before the onset of symptoms or changes in spirometry and imaging. Despite their importance, they have proven relatively difficult to study. This is in part due to their relative inaccessibility to biopsy and their small size which makes their imaging difficult. Traditional lung function tests may only become abnormal once there is a significant burden of disease within them. This has led to the term 'the quiet zone' of the lung. In recent years, more specialised tests have been developed which may detect these changes earlier, perhaps offering the possibility of earlier diagnosis and intervention. These tests are now moving from the realms of clinical research laboratories into routine clinical practice and are increasingly useful in the diagnosis and monitoring of respiratory diseases. This article gives an overview of small airways physiology and some of the routine and more advanced tests of airway function.
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Affiliation(s)
- William McNulty
- National Heart and lung Institute, Imperial College London and Royal Brompton Hospital, London, UK
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22
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Irreversible acinar airway abnormality in well controlled asthma. Respir Med 2014; 108:1601-7. [PMID: 25175658 DOI: 10.1016/j.rmed.2014.07.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 06/06/2014] [Accepted: 07/29/2014] [Indexed: 11/24/2022]
Abstract
RATIONALE Even in stable asthma patients, acinar ventilation distribution can be abnormal, and we aimed to specifically maximize its reversibility by switching patients from a standard inhaled corticosteroid (iCS) to a fine particle iCS formulation. METHODS For this prospective double-blind double-dummy randomized study, 66 stable asthma patients under maintenance iCS (equivalent budesonide ≤ 800 μg/day) were screened for abnormal baseline acinar ventilation heterogeneity (Sacin). After a 3-week run-in period, 35 eligible patients were randomized to fine particle beclomethasone (HFA-BDP; Qvar Autohaler) or to budesonide (DPI-BUD; Pulmicort Turbohaler). Asthma Control Test (ACT) score and various lung function indices reflecting the small airways were obtained at baseline, after 6 and 12 weeks. RESULTS Thirty one patients [age:52 ± 17(SD) years; FEV1:76 ± 19(SD)%pred] completed the study (DPI-BUD:n = 16; HFA-BDP:n = 15). After 6 and 12 weeks, there were no significant changes in acinar or conductive ventilation heterogeneity, nor in mid-expiratory flow, RV/TLC, closing capacity, impulse oscillometry indices (resistance, reactance), bronchial NO production or alveolar NO, in either treatment arm. Asthma control was maintained in both arms. CONCLUSION In stable asthma patients with small airways dysfunction under maintenance therapy, there is a residual functional abnormality in the lung periphery which is probably not eosinophilic in origin and cannot be normalized with the iCS formulations under study. ISRCTN17195095.
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Bulac S, Cimrin A, Ellidokuz H. The effect of beclometasone dipropionate/formoterol extra-fine fixed combination on the peripheral airway inflammation in controlled asthma. J Aerosol Med Pulm Drug Deliv 2014; 28:82-7. [PMID: 25050594 DOI: 10.1089/jamp.2013.1062] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Suppression of small airway inflammation may contribute to achieving asthma control. We aimed to evaluate the additional effect of beclometasone dipropionate/formoterol (BDP/F) hydrofluoroalkane (HFA) pressurized metered dose inhaler (pMDI) (BDP/F-HFA 100/6 μg pMDI) on airway inflammation and functional parameters in asthma cases, who were optimally controlled by maintenance therapy. METHODS Ninety-five controlled asthmatic patients were included. They were grouped as Group 1 [budesonide/formoterol 320/9 μg dry powder inhaler (DPI)] and Group 2 (fluticasone/salmeterol 500/50 μg DPI) according to the combination they used. Then Group 3 was established by random selection from these two groups, and BDP/F-HFA 100/6 μg pMDI treatment was prescribed. All patients were evaluated in the beginning of the study and were re-evaluated at the end of a 3-week treatment period by spirometry, exhaled nitric oxide (eNO) levels, and small airway functional indices, namely, Sacin and Scond values. RESULTS There was no significant statistical difference in terms of age, height, weight, disease duration, symptoms, and spirometric parameters between the groups. There was a significant decrease in eNO levels in asthma cases who were on BDP/F-HFA therapy (p=0.001). A significant improvement in Sacin values at the end of the treatment period was observed in cases treated with BDP/F-HFA (p=0.001), indicating that inflammation was suppressed in peripheral airways. CONCLUSIONS These results emphasize that asthma treatment has mainly focused on the strategy to keep the disease under control; maintaining optimal functional level might be underestimated. BDP/F-HFA may have an additional favorable effect on the peripheral airway inflammation in the controlled asthma.
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Affiliation(s)
- Serpil Bulac
- 1 Dokuz Eylul University Medical School , Department of Pulmonary Diseases, Izmir, Turkey
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Bake B, Viklund E, Olin AC. Effects of pollen season on central and peripheral nitric oxide production in subjects with pollen asthma. Respir Med 2014; 108:1277-83. [PMID: 25052059 DOI: 10.1016/j.rmed.2014.06.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 06/02/2014] [Accepted: 06/23/2014] [Indexed: 12/26/2022]
Abstract
BACKGROUND Pollen exposure of allergic subjects with asthma causes increased nitric oxide (NO) in exhaled air (FENO) suggestive of increased airway inflammation. It is, however, unclear to what extent NO production in peripheral airways and alveoli are involved. OBJECTIVES The aim of the present investigation was to analyze the relationship between central and peripheral components of FENO to clarify the distribution of pollen induced inflammation in asthma. SUBJECTS AND METHODS 13 pollen allergic non-smoking subjects with mild-intermittent asthma and 12 healthy non-smoking control subjects were examined with spirometry and FENO at flows between 50 and 270 mL/s during and out of pollen season. RESULTS Spirometry was normal and unaffected by season in subjects with asthma as well as controls. Out of season subjects with asthma had significantly higher FENO, elevated airway production (JáwNO) and preacinar/acinar production (CANO) than controls. Pollen exposure resulted in significantly increased FENO and JáwNO but not CANO. FENO among controls were not affected by season. Individual results showed, however, that CANO increased substantially in a few subjects with asthma. The increased CANO in subjects with asthma may be explained by increased NO production in preacinar/acinar airways and back diffusion towards the alveoli. CONCLUSIONS The findings may indicate that subjects with allergic asthma have airway inflammation without alveolar involvement outside the pollen season and pollen exposure causes a further increase of airway inflammation and in a few subjects obstruction of intra acinar airways causing impeded back diffusion. Increased NO production in central airways, unassociated with airway obstruction could be an alternative explanation. These effects were not disclosed by spirometry.
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Affiliation(s)
- Björn Bake
- Occupational and Environmental Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden; Respiratory Medicine and Allergology, Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Emilia Viklund
- Occupational and Environmental Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Anna-Carin Olin
- Occupational and Environmental Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden; Respiratory Medicine and Allergology, Sahlgrenska Academy at University of Gothenburg, Sweden.
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Abstract
Non-uniform distribution of inspired gas within the lung, termed ventilation heterogeneity, is present in patients with even mild asthma. Current evidence strongly supports ventilation heterogeneity as a fundamental derangement of lung function in asthma that contributes per se to hypoxemia and airway hyper-responsiveness. An extreme example of ventilation heterogeneity is the identification by hyperpolarized gas MRI of lung regions with no ventilation, termed filling defects. Lung filling defects in patients with asthma can persist over time, increase in size with methacholine-induced bronchospasm and more likely are caused by obstruction of the peripheral and not the proximal airways. Ventilation heterogeneity can be quantified in the conducting and acinar lung zones with the multiple gas washout method, and in the acinar zone does not fully resolve following bronchodilator treatment in patients with asthma. In prospective studies, the degree of ventilation heterogeneity at baseline predicts airway hyper-responsiveness and response to corticosteroid dose titration. An important unanswered question is the relationship of airways inflammation to ventilation heterogeneity. In consideration of the importance of ventilation heterogeneity in its pathobiology, asthma is more a focal disorder with regional pathology akin to regional ileitis and not the generalized disorder of the airways as it has been viewed in the past.
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Affiliation(s)
- W Gerald Teague
- Division of Respiratory Medicine, Allergy, and Immunology, Department of Pediatrics and
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Singer F, Abbas C, Yammine S, Casaulta C, Frey U, Latzin P. Abnormal small airways function in children with mild asthma. Chest 2014; 145:492-499. [PMID: 24091465 DOI: 10.1378/chest.13-0784] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Small airways disease is a hallmark in adults with persistent asthma, but little is known about small airways function in children with mild asthma and normal spirometry. We assessed ventilation heterogeneity, a marker of small airways function, with an easy tidal breath single-breath washout (SBW) technique in school-aged children with mild asthma and normal FEV1 and healthy age-matched control subjects. METHODS The primary outcome was the double-tracer gas phase III slope (SDTG), an index of ventilation heterogeneity in acinar airways derived from the tidal double-tracer gas SBW test. The second outcome was the nitrogen phase III slope (SN2), an index of global ventilation heterogeneity derived from the tidal nitrogen SBW test using pure oxygen. Triplicate SBW and spirometry tests were performed in healthy children (n=35) and children with asthma (n=31) at baseline and in children with asthma after bronchodilation. RESULTS Acinar (SDTG) but not global (SN2) ventilation heterogeneity was significantly increased in asthma despite normal FEV1. Of the 31 children with asthma, abnormal results were found for SDTG (≤-2 z scores) in 11; forced expiratory flow, midexpiratory phase (FEF25%-75%) in three; and FEV1 in zero. After bronchodilation, SDTG, SN2, FEF25%-75%, and FEV1 significantly changed (mean [95% CI] change from baseline, 36% [15%-56%], 38% [18%-58%], 17% [9-25%], and 6% [3%-9%], respectively). CONCLUSIONS Abnormal acinar ventilation heterogeneity in one-third of the children suggests that small airways disease may be present despite rare and mild asthma symptoms and normal spirometry. The easy tidal SBW technique has considerable potential as a clinical and research outcome in children with asthma.
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Affiliation(s)
- Florian Singer
- University Children's Hospital Zurich, Zurich; University Children's Hospital Bern, Bern
| | | | - Sophie Yammine
- University Children's Hospital Bern, Bern; University Children's Hospital Basel, Basel, Switzerland
| | | | - Urs Frey
- University Children's Hospital Zurich, Zurich; University Children's Hospital Basel, Basel, Switzerland
| | - Philipp Latzin
- University Children's Hospital Bern, Bern; University Children's Hospital Basel, Basel, Switzerland.
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Cattoni I, Guarnieri G, Tosetto A, Mason P, Scarpa MC, Saetta M, Maestrelli P. Mechanisms of decrease in fractional exhaled nitric oxide during acute bronchoconstriction. Chest 2013; 143:1269-1276. [PMID: 23370456 DOI: 10.1378/chest.12-1374] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Fractional exhaled nitric oxide measured at expiratory flow of 50 mL/s (Feno50), a biomarker of airway inflammation, is affected by changes in airway caliber. Whether a lower Feno50 level during bronchoconstriction is only an artifact due to the strong flow dependence of this parameter is controversial. METHODS We aimed to evaluate the dynamics of airway and alveolar nitric oxide (NO) during acute bronchoconstriction induced by methacholine. Exhaled NO was measured at expiratory flows of 10, 50, 100, 150, and 250 mL/s before and after metacholine in 26 responders to methacholine and 37 nonresponders. Flow-independent parameters (airway wall NO flux, airway NO diffusing capacity, airway wall NO concentration, alveolar NO concentration) were calculated using a two-compartment model, and correction for NO axial back diffusion was applied. RESULTS Bronchoconstriction in responders was associated with a decrease in Feno50 (-28%, P < .0001), in airway wall NO flux (-34%, P < .0001), and in airway NO diffusing capacity (-15%, P < .05). In contrast, alveolar NO concentration was not affected by bronchoconstriction. Postmethacholine changes in Feno50 were more strictly related to the ventilation distribution, assessed by single-breath carbon monoxide uptake, than to larger airways caliber, assessed by FEV1. When bronchoconstriction was reversed by salbutamol, airway wall NO flux and airway NO diffusing capacity returned to values comparable to those measured premethacholine. CONCLUSIONS The changes in airway caliber induced by noninflammatory stimuli alter NO transport in the lung. The changes in NO dynamics are limited to conductive airways and are characterized by a reduction of NO flow to luminal space.
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Affiliation(s)
- Ilaria Cattoni
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - Gabriella Guarnieri
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - Alessandro Tosetto
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - Paola Mason
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - Maria C Scarpa
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - Marina Saetta
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - Piero Maestrelli
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy.
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Singer F, Kieninger E, Abbas C, Yammine S, Fuchs O, Proietti E, Regamey N, Casaulta C, Frey U, Latzin P. Practicability of nitrogen multiple-breath washout measurements in a pediatric cystic fibrosis outpatient setting. Pediatr Pulmonol 2013; 48:739-46. [PMID: 22888105 DOI: 10.1002/ppul.22651] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 06/29/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND Although lung clearance index (LCI) is a sensitive indicator of mild cystic fibrosis (CF) lung disease, it is rarely measured due to lengthy protocols and the commercial unavailability of multiple-breath washout (MBW) setups and tracer gases. We used a newly validated, commercially available nitrogen (N2 ) MBW setup to assess success rate, duration, and variability of LCI within a 20 min timeframe, during clinical routine. We also evaluated the relationship between LCI and other clinical markers of CF lung disease. METHODS One hundred thirty six children (83 with CF) between 4 and 16 years were studied in a pediatric CF outpatient setting. One hundred eighteen out of 136 children were naïve to MBW. Within 20 min, each child was trained, N2 MBW was performed, and LCI was analyzed. We assessed intra- and between-test reproducibility in a subgroup of children. RESULTS At least one LCI was feasible in 123 (90%) children, with a mean (range) of 3.3 (1.2-6.4) min per test. Two or more measurements were feasible in 56 (41%) children. Comparing LCI in CF versus controls, LCI mean (SD) was 12.0 (3.9) versus 6.1 (0.9), and the intra- and inter-test coefficient of repeatability was 1.00 versus 0.81 and 0.96 versus 0.62, respectively. LCI was correlated with spirometry, blood gases, and Pseudomonas aeruginosa infection. CONCLUSIONS Using available N2 MBW equipment, LCI measurements are practical and fast in children. LCI is correlated with markers of CF lung disease. Longer timeframes would be required for triplicate N2 MBW tests in inexperienced children.
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Affiliation(s)
- Florian Singer
- Division of Respiratory Medicine, Department of Pediatrics, University Hospital of Bern, Bern, Switzerland
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29
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Konstantinos Katsoulis K, Kostikas K, Kontakiotis T. Techniques for assessing small airways function: Possible applications in asthma and COPD. Respir Med 2013; 119:e2-e9. [PMID: 23764129 DOI: 10.1016/j.rmed.2013.05.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 04/08/2013] [Accepted: 05/06/2013] [Indexed: 11/28/2022]
Abstract
In recent years special interest has been expressed for the contribution of small airways in the pathophysiology, clinical manifestations and treatment of asthma and COPD. Small airways contribute little to the total respiratory resistance so that extensive damage of small airways may occur before the appearance of any symptoms, and this is the reason why they are characterized as the "silent zone" of airways. Furthermore, the peripheral localization of the small airways and their small diameter constitutes difficult their direct assessment. Thus, they are usually studied indirectly, taking advantage of the effects of their obstruction, such as premature closure, air trapping, heterogeneity of ventilation, and lung volume dependence of airflow limitation. Today, several heterogeneous methods for the assessment of small airways are available. These can be either functional (spirometry, plethysmography, resistance measurements, nitrogen washout, alveolar nitric oxide, frequency dependence of compliance, flow-volume curves breathing mixture of helium-oxygen) or imaging (mainly through high resolution computed tomography). The above-mentioned methods are summarized in Table 1. However, no method is currently considered as the "gold standard" and it seems that combinations of tests are needed. Furthermore, it is not clear whether the small airways are affected in all patients with asthma or COPD and their clinical significance remains under investigation. Well-designed future studies with large numbers of patients are expected to reveal which of the methods for assessing the small airways is the most accurate, reliable and reproducible, for which patients, and which can be used for the evaluation of the effects of treatment.
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Ivancsó I, Böcskei R, Müller V, Tamási L. Extrafine inhaled corticosteroid therapy in the control of asthma. J Asthma Allergy 2013; 6:69-80. [PMID: 23776339 PMCID: PMC3681407 DOI: 10.2147/jaa.s25415] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Small airways disease plays an important role in the pathogenesis of asthma, but assessment of small airways impairment is not easy in everyday clinical practice. The small airways can be examined by several invasive and noninvasive methods, most of which can at present be used only in the experimental setting. Inhalers providing extrafine inhaled corticosteroid particle sizes may achieve sufficient deposition in the peripheral airways. Many studies have reported the beneficial effects of extrafine inhaled corticosteroids on inflammation, ie, on dysfunction in both the central and distal airways in asthmatics, and there are some data on asthma phenotypes in which the small airways seem to be affected more than in other phenotypes, including nocturnal asthma, severe steroid-dependent or difficult-to-treat asthma, asthma complicated by smoking, elderly asthmatic patients and/or patients with fixed airflow obstruction, and asthmatic children. The relevant randomized controlled clinical trials indicate that the efficacy of extrafine and nonextrafine inhaled corticosteroid formulations is similar in terms of primary endpoints, but there are certain clinically important endpoints for which the extrafine formulations show additional benefits.
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Affiliation(s)
- István Ivancsó
- Department of Pulmonology, Semmelweis University, Budapest, Hungary
| | - Renáta Böcskei
- Department of Pulmonology, Semmelweis University, Budapest, Hungary
| | - Veronika Müller
- Department of Pulmonology, Semmelweis University, Budapest, Hungary
| | - Lilla Tamási
- Department of Pulmonology, Semmelweis University, Budapest, Hungary
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Thompson BR, Douglass JA, Ellis MJ, Kelly VJ, O'Hehir RE, King GG, Verbanck S. Peripheral lung function in patients with stable and unstable asthma. J Allergy Clin Immunol 2013; 131:1322-8. [PMID: 23561802 DOI: 10.1016/j.jaci.2013.01.054] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 01/22/2013] [Accepted: 01/24/2013] [Indexed: 11/20/2022]
Abstract
BACKGROUND Exacerbations of asthma are thought to be caused by airflow obstruction resulting from airway inflammation, bronchospasm, and mucus plugging. Histologic evidence suggests the small airways, including acinar air spaces, are involved; however, this has not been corroborated in vivo by measurements of peripheral small-airway function. OBJECTIVE We sought to determine whether asthma severity is linked to small-airway function, particularly in patients with acute severe asthma. METHODS Eighteen subjects admitted for an asthma exacerbation underwent lung function testing, including measures of acinar ventilation heterogeneity (S(acin)) and conductive ventilation heterogeneity (S(cond)) using the multiple-breath nitrogen washout. Treatment requirement was defined according to Global Initiative for Asthma scores. Data were compared with those obtained in 19 patients with stable asthma. RESULTS For the asthma exacerbation group, the median FEV1 was 59% of predicted value (95% CI, 45% to 75% of predicted value), the median S(cond) value was 185% of predicted value (95% CI, 119% to 245% of predicted value), and the median S(acin) value was 225% of predicted value (95% CI, 143% to 392% of predicted value). FEV1 (percent predicted) was correlated with S(acin) (percent predicted) values (Spearman rho = -0.67, P = .006) but not with S(cond) (percent predicted) values (P > .1). The Global Initiative for Asthma score was significantly related to S(acin) (percent predicted) (Spearman rho = 0.59, P = .016) but not to S(cond) (percent predicted) values (P > .1). The unstable group was characterized by considerably lower forced vital capacity (P < .001) and higher S(cond) (P = .001) values than the unstable group. In a subgroup of 11 unstable patients who could be reviewed after 4 weeks, FEV1, forced vital capacity, S(acin), and S(cond) values showed marked improvements. CONCLUSION Our findings suggest that unstable asthma is characterized by a combined abnormality in the acinar and conductive lung zones, both of which are partly reversible. Functional abnormality in the acinar lung zone in particular showed a direct correlation with airflow obstruction and treatment requirement in patients with acute severe asthma.
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Affiliation(s)
- Bruce R Thompson
- Department of Allergy, Immunology and Respiratory Medicine, The Alfred Hospital and Monash University, Melbourne, Australia.
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Multiple breath nitrogen washout profiles in asthmatic patients: what do they mean clinically? J Allergy Clin Immunol 2013; 131:1329-30. [PMID: 23541321 DOI: 10.1016/j.jaci.2013.02.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 02/15/2013] [Indexed: 11/23/2022]
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Nakaji H, Petrova G, Matsumoto H, Iwata T, Ito I, Oguma T, Inoue H, Tajiri T, Nagasaki T, Kanemitsu Y, Niimi A, Mishima M. Effects of 24-week add-on treatment with ciclesonide and montelukast on small airways inflammation in asthma. Ann Allergy Asthma Immunol 2013; 110:198-203.e3. [PMID: 23548532 DOI: 10.1016/j.anai.2012.12.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/26/2012] [Accepted: 12/18/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND Eosinophilic inflammation of the small airways is a key process in asthma that often smolders in treated patients. The long-term effects of add-on therapy on the persistent inflammation in the small airways remain unknown. OBJECTIVE To examine the effects of add-on therapy with either ciclesonide, an inhaled corticosteroid with extrafine particles, or montelukast on small airway inflammation. METHODS Sixty patients with stable asthma receiving inhaled corticosteroid treatment were enrolled in a randomized, open-label, parallel comparison study of 24-week add-on treatment with ciclesonide or montelukast. Patients were randomly assigned to 3 groups: ciclesonide (n = 19), montelukast (n = 22), or no add-on as controls (n = 19). At baseline and at weeks 4, 12, and 24, extended nitric oxide analysis; pulmonary function tests, including impulse oscillometry; blood eosinophil counts; and asthma control tests (ACTs) were performed. RESULTS A total of 18 patients in the ciclesonide group, 19 in the montelukast group, and 15 in the control group completed the study and were analyzed. With repeated-measures analysis of variance, ciclesonide produced a significant decrease in alveolar nitric oxide and a significant improvement in ACT scores over time. Montelukast produced significant decreases in alveolar nitric oxide concentrations and blood eosinophil counts over time and slightly improved ACT scores, whereas no such changes were observed in the control group. Alveolar nitric oxide concentrations with ciclesonide and reactance area at low frequencies with montelukast produced greater improvements over time compared with control. CONCLUSION Ciclesonide add-on therapy and montelukast add-on therapy may act differently, but both separately can improve small airway abnormalities and provide better asthma control. TRIAL REGISTRATION umin.ac.jp/ctr Identifier: UMIN000001083.
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Affiliation(s)
- Hitoshi Nakaji
- Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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van den Berge M, ten Hacken NHT, van der Wiel E, Postma DS. Treatment of the bronchial tree from beginning to end: targeting small airway inflammation in asthma. Allergy 2013; 68:16-26. [PMID: 23210509 DOI: 10.1111/all.12062] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2012] [Indexed: 01/19/2023]
Abstract
Asthma is a chronic respiratory disease, characterized by airway obstruction and inflammation. Increasing evidence shows that the small airways contribute significantly to the clinical expression and severity of asthma. Traditionally, high levels of disease activity are thought to be necessary before symptoms occur in the small airways because of their large reserve capacity. However, this concept is being challenged and increasing evidence shows small airway disease to be associated with symptoms, disease severity, and bronchial hyper-responsiveness. Particle size and distribution are of key importance when developing inhaled treatments for small airway disease. The availability of small-particle aerosols such as HFA-ciclesonide and HFA-beclomethasone dipropionate (HFA-BDP) enables a higher drug deposition into the peripheral lung and potentially provides additional clinical benefits compared with large-particle treatment. However, improved methods are needed to monitor and assess small airway disease and its response to treatment because conventional spirometry mainly reflects large airway function. This remains a challenging area requiring further research. The aim of the current manuscript is to review the clinical relevance of small airway disease and the implications for the treatment of asthma.
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Affiliation(s)
- M van den Berge
- Department of Pulmonary Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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The importance of imaging and physiology measurements in assessing the delivery of peripherally targeted aerosolized drugs. Ther Deliv 2012; 3:1329-45. [DOI: 10.4155/tde.12.113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Considerable recent effort has been directed towards developing new aerosol formulations and delivery devices that can target drugs to the lung periphery. In order to determine the efficacy of targeted drug therapy, it is essential that the peripheral lung region be adequately assessed. Imaging of the airways structure and pathology has greatly advanced in the last decade and this rate of growth is accelerating as new technologies become available. Lung imaging continues to play an important role in the study of the peripheral airways and, when combined with state-of-the-art lung function measurements and computational modeling, can be a powerful tool for investigating the effects of inhaled medication. This article focuses on recent strategies in imaging and physiological measurements of the lungs that allow the assessment of inhaled medication delivered to the periphery and discusses how these methods may help to further optimize and refine future aerosol delivery technology.
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Abstract
Noninvasive physiological measurements are reviewed that have been reported in the literature with the specific aim being to study the small airways in lung disease. This has mostly involved at-the-mouth noninvasive measurement of flow, pressure or inert gas concentration, with the intent of deriving one or more indices that are representative of small airway structure and function. While these measurements have remained relatively low-tech, the effort and sophistication increasingly reside with the interpretation of such indices. When aspiring to derive information at the mouth about structural and mechanical processes occurring several airway generations away in a complex cyclically changing cul-de-sac structure, conceptual or semi-quantitative lung models can be valuable. Two assumptions that are central to small airway structure-function measurement are that of an average airway change at a given peripheral lung generation and of a parallel heterogeneity in airway changes. While these are complementary pieces of information, they can affect certain small airways tests in confounding ways. We critically analyzed the various small airway tests under review, while contending that negative outcomes of these tests are probably a true reflection of the fact that no change occurred in the small airways. Utmost care has been taken to not favor one technique over another, given that most current small airways tests still have room for improvement in terms of rendering their content more specific to the small airways. One way to achieve this could consist of the coupling of signals collected at the mouth to spatial information gathered from imaging in the same patient.
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Affiliation(s)
- Sylvia Verbanck
- Respiratory Division, University Hospital UZ Brussel, Brussels, Belgium.
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Anderson WJ, Zajda E, Lipworth BJ. Are we overlooking persistent small airways dysfunction in community-managed asthma? Ann Allergy Asthma Immunol 2012; 109:185-189.e2. [PMID: 22920073 DOI: 10.1016/j.anai.2012.06.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 06/20/2012] [Accepted: 06/29/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND Whether small airways dysfunction persists in patients with asthma receiving standard community treatment is unknown. Impulse oscillometry (IOS) is a sensitive measure of small airways function. OBJECTIVE To assess the degree of small airways dysfunction in a cross-section of patients with community-managed asthma. METHODS We analyzed primary care referral data from patients with persistent asthma (n = 378) receiving standard community therapy, screened using spirometry and IOS. We compared patients by British Thoracic Society asthma treatment step (2-4). RESULTS Step 2 patients were not different from step 3 patients receiving long-acting beta-agonist (LABA). Step 4 patients differed from step 2 by: higher inhaled corticosteroid (ICS) dose (P < .0001); lower forced expiratory volume in 1 second (FEV(1)%; P = .02) and forced mid-expiratory flow (FEF(25-75%); P = .001); higher frequency of resonance (F(res); P = .02) and peripheral airway resistance (R5-R20; P = .006); whereas for steps 3 vs 4 there were differences in F(res) (P < .05) and R5-R20 (P = .006). There were high proportions of abnormality for R5-R20 (>0.03 kPa/L/s) at steps 2, 3, and 4, respectively: 64.6%, 63.5%, and 69.9%. Step 2 patients receiving extra-fine particle ICS demonstrated lower total airway resistance at 5Hz (R5) vs patients receiving standard ICS (124.1% vs 138.3%, P < .05), with no difference in FEV(1). At step 4, R5 remained elevated at 141.3% despite concomitant LABA, with only 2.4% using extra-fine ICS. CONCLUSION Persistent small airways dysfunction occurs despite treatment at steps 2 through 4 of current asthma guidelines. Extra-fine ICS may reduce airway resistance at step 2. Prospective studies with extra-fine ICS ± LABA at steps 2 through 4 are required to discern whether improving small airways function might result in long-term improved control.
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Affiliation(s)
- William J Anderson
- Asthma and Allergy Research Group, University of Dundee, Scotland, United Kingdom
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Abstract
Asthma is a lung disease characterized by inflammation and remodeling of the airways. It is now widely accepted that airway inflammation and remodeling occur not only in the central airways but also in the small airways and even in the lung parenchyma. Inflammation of the distal lung can be observed even in mild asthmatics with normal or noncompromised lung function. Moreover, the small airways and the lung parenchyma can produce many Th2 cytokines and chemokines involved in initiation and perpetuation of the inflammatory process. In addition, the distal parts of the bronchial tree have been recognized as a predominant site of airflow obstruction in many asthmatics. In fact, the inflammation at this distal site has been described as more severe when compared to the large airway inflammation, and evidence of remodeling in the lung periphery is emerging. Recognition of asthma as a disease of the entire respiratory tract has an important clinical significance, highlighting the need to also consider the distal lung as a target in any therapeutic strategy for effective treatment of this disease.
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Affiliation(s)
- Qutayba Hamid
- Meakins Christie Laboratories, McGill University, Montreal, Que., Canada.
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Farah CS, King GG, Brown NJ, Peters MJ, Berend N, Salome CM. Ventilation heterogeneity predicts asthma control in adults following inhaled corticosteroid dose titration. J Allergy Clin Immunol 2012; 130:61-8. [DOI: 10.1016/j.jaci.2012.02.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 02/03/2012] [Accepted: 02/16/2012] [Indexed: 10/28/2022]
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Usmani OS, Barnes PJ. Assessing and treating small airways disease in asthma and chronic obstructive pulmonary disease. Ann Med 2012; 44:146-56. [PMID: 21679101 DOI: 10.3109/07853890.2011.585656] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Asthma and chronic obstructive pulmonary disease (COPD) are chronic inflammatory disorders of the respiratory tract that are characterized by airflow limitation. They are distinct conditions with different causes, structural changes, and immunopathology. The pathophysiology in asthma and COPD involves not only the proximal large airways, but also the distal small airways, and thus the small airways are an important therapeutic target in the treatment of both diseases. The assessment of diseased distal small airways is challenging. Extensive disease can be present in the small airways with little abnormality in conventional pulmonary function tests. Recent advances in imaging technologies have led to better spatial resolution to assess small airways morphology non-invasively. New physiological tests have been developed to detect disease and response to therapy in regional airways. Improving the efficiency of existing aerosolized therapy to direct drug to the appropriate lung regions may improve clinical efficacy. Approaches to target distal lung regions include developing new drug formulations with smaller aerosol particle size or using inhaler devices that emit aerosolized drug at slow inhalation flows. Large studies are needed to determine whether better distal lung deposition leads to improvements in small airways function that are translated into clinically significant patient outcomes.
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Affiliation(s)
- Omar S Usmani
- Airway Disease Section, National Heart and Lung Institute, Imperial College, London, UK.
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Abstract
PURPOSE OF REVIEW The small airways play an important yet poorly targeted role in asthma pathophysiology, leading to increased morbidity in asthma patients. Assessing inflammation and remodeling in these airways, determining the contribution of small airways to lung dysfunction and enhancing drug delivery to the distal regions of the lung remain challenging. The purpose of this review is to highlight recent advances in our understanding of small airways involvement in asthma. RECENT FINDINGS Inflammation in the small airways can be evaluated through exhaled gas measurements, most often nitric oxide. However, additional exhaled biomarkers have recently been described. Considerable infiltration of mast cells in the distal lung and extensive structural changes to the small airways have also been demonstrated. Advances have been made in the functional assessment of small airways, particularly in the measurement of small airway compliance and ventilation defects and in studies investigating the impact of small particle inhaled corticosteroid treatment on lung function. SUMMARY Experimental assessments of small airways inflammation, remodeling and function have provided novel insights into the importance of the distal regions of the lung in asthma pathology. Further advances in drug delivery to the small airways have the potential to improve asthma control.
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Verbanck S, Paiva M, Schuermans D, Hanon S, Vincken W, Van Muylem A. Relationships between the lung clearance index and conductive and acinar ventilation heterogeneity. J Appl Physiol (1985) 2011; 112:782-90. [PMID: 22162528 DOI: 10.1152/japplphysiol.01221.2011] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The lung clearance index (LCI) derived from a multiple breath washout test has regained considerable popularity in recent years, alternatively being promoted as an early detection tool or a marker of small airways function. In this study, we systematically investigated the link between LCI and indexes of acinar and conductive airways ventilation heterogeneity (Sacin, Scond) to assess potential contributions from both lung zones. Relationships were examined in 55 normal subjects after provocation, where only Scond is known to be markedly increased, and in 55 asthma patients after bronchodilation, in whom both Scond and Sacin ranged between normal and abnormal. LCI was correlated to Scond in both groups (R = 0.37-0.43; P < 0.01 for both); in the asthma group, LCI was also tightly correlated to Sacin (R = 0.70; P < 0.001). Potential mechanisms operational at various levels of the bronchial tree were identified by considering washout curvilinearity in addition to LCI to distinguish specific ventilation and dead space effects (also illustrated by simple 2-compartment model simulations). Although the asthma data clearly demonstrate that LCI can reflect very peripheral ventilation heterogeneities, the normal provocation data also convincingly show that LCI increases may be the exclusive result of far more proximal ventilation heterogeneities. Because LCI potentially includes heterogeneities at all length scales, it is suggested that ventilation imaging in combination with LCI measurement at the mouth could identify the scale of relevant ventilation heterogeneities. In the meantime, interpretations of LCI results in the clinic based on washout curves collected at the mouth should be handled with caution.
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Affiliation(s)
- Sylvia Verbanck
- Respiratory Division, Univ. Hospital UZ Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium.
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[Inflammation and remodeling of the distal airways: studies in humans and experimental models]. Arch Bronconeumol 2011; 47 Suppl 2:2-9. [PMID: 21640278 DOI: 10.1016/s0300-2896(11)70014-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Asthma is characterized by inflammation and remodeling of the airways, giving rise to airway obstruction and symptoms of wheezing, chest tightness, cough and dyspnea. Most of these observations arise from the study of samples obtained from the central airways by distinct methods. However, it is currently accepted that this inflammatory process occurs not only in the central airway but also in the small airway and even in the pulmonary parenchyma of all asthmatic patients, even those with mild asthma. CD4+ lymphocytes, activated eosinophils and IL-5 mRNA expression are present in a greater quantity in the small airways. Also present is remodeling, with an increase in submucosal thickness, the muscular layer and adventitia. This inflammatory process causes a disconnection between the pulmonary parenchyma and the airway, giving rise to obstruction of the small airway, which is currently considered to be predominant in asthmatic patients. Likewise, studies of experimental asthma in animals support the substantial role of the distal airway. Recognition that asthma affects the entire airway could be clinically important and lead to the distal lung being considered as a target in any effective therapeutic strategy. However, longitudinal studies are required to evaluate the impact of distal airway inflammation and its treatment in asthma.
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de Diego Damiá A, Vega Chicote JM. [Therapeutic approach to the distal airways in asthma]. Arch Bronconeumol 2011; 47 Suppl 2:27-31. [PMID: 21640282 DOI: 10.1016/s0300-2896(11)70018-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Bronchial asthma is a chronic inflammatory disease that affects both the large-caliber airways and the smaller-caliber bronchioles. In the last few years, a major therapeutic advance has been made with the development of new systems of inhalation solutions, which produce extra-fine particles, achieving better lung deposition throughout the airways and reducing oropharyngeal deposition. These formulations have improved the effectiveness of bronchodilation and particularly the antiinflammatory effect. The use of long-acting b2-adrenergic steroids in extra-fine formulation, whether alone or in combinations of fixed doses, improves drug distribution throughout the bronchial tree, enhancing the therapeutic effect with lower doses of drugs. Leukotriene receptor antagonists have shown their effect on the small airways in asthmatic patients, both in studies of pulmonary resistance and pulmonary volumes and in imaging studies.
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Álvarez Puebla MJ, García Río F. [Physiology and physiopathology of the distal airways in asthma]. Arch Bronconeumol 2011; 47 Suppl 2:10-6. [PMID: 21640279 DOI: 10.1016/s0300-2896(11)70015-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The small airways are those with an internal diameter of less than 2 mm. The contribution of these airways to total airflow resistance is small in healthy individuals but can represent 50-90 % of total airflow resistance in asthmatics. Suspicion of small airways disease has been based on reduction of midexpiratory and instantaneous flows, although wide variability in their values and the absence of a sufficiently validated cut-off point has limited their clinical application. Static pulmonary volumes can provide indirect evidence of the state of the most distal airways, revealing two effects of their alteration: air trapping and dynamic hyperinflation. While determination of airway resistance by plethysmography and of respiratory system resistance measured by flow interruption are highly non-specific, the forced oscillation technique allows obstruction of the small airways to be distinguished from that of medium-caliber airways. The characteristic pattern of peripheral obstruction includes a decrease in frequency-dependent resistance, reduced reactivity and an increase in resonance frequency. Single-or multiple-breath nitrogen washout can also provide specific information on the small airways, although the apparatus required is less frequently available. Analysis through bicompartmental models of exhaled nitric oxide allows alveolar nitric oxide concentrations to be determined, which seems to provide information on inflammatory activity in the small airways.
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García-Río F, Casitas R, Romero D. Utility of two-compartment models of exhaled nitric oxide in patients with asthma. J Asthma 2011; 48:329-34. [PMID: 21504346 DOI: 10.3109/02770903.2011.565847] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Two-compartment models provide more precise information about the contribution of the different portions of the airways to exhaled nitric oxide (NO). Airway wall concentration of NO (Caw,NO) and maximum flux of NO in the airways (J'aw,NO) reflect the tissue production rate of NO and they can be modified by corticosteroids. The airway wall diffusing capacity of NO (Daw,NO) depends on diverse physical and anatomical determinants of the airways, such as gas exchange surface area. Daw,NO can be modified by structural and physiological changes that are characteristic of airway remodeling, which take place over the long term. The alveolar concentration of NO (Calv,NO) represents the degree of small airway inflammation. The persistence of high Calv,NO in patients treated with inhaled corticosteroids could reflect the incapacity of these drugs to reach distal locations due to the heterogeneity of the acinar ventilation. In this review, we evaluate the parameters provided by the compartmentalized analysis of exhaled NO that could be useful in characterizing asthma patients.
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Advances in environmental and occupational respiratory disease in 2010. J Allergy Clin Immunol 2011; 127:696-700. [PMID: 21377039 DOI: 10.1016/j.jaci.2011.01.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 01/05/2011] [Indexed: 12/18/2022]
Abstract
2010 Found a number of significant advances in environmental and occupational respiratory disease. The role of sensitization and the subsequent production of allergic disease have been explored. New allergens and their T- and B-cell epitopes have been characterized. Novel approaches to the diagnosis and evaluation of food allergy have been described. The role of pollutants as they affect respiratory disease and the effects of age extremes on sensitization and asthma have been addressed. Significant advances in the understanding of inflammatory changes in both the upper and lower respiratory systems occurred. Novel therapeutic approaches have been explored, including the development of hypoallergens from improved molecular biology techniques. New effective approaches to asthma therapy have been identified. Exposure reduction through air filtration and novel immunotherapy approaches, such as sublingual therapy, have made significant advances.
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Keen C, Olin AC, Wennergren G, Gustafsson P. Small airway function, exhaled NO and airway hyper-responsiveness in paediatric asthma. Respir Med 2011; 105:1476-84. [PMID: 21570274 DOI: 10.1016/j.rmed.2011.04.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/21/2011] [Accepted: 04/11/2011] [Indexed: 11/15/2022]
Abstract
BACKGROUND Asthma is a chronic inflammatory airway disorder known to involve the peripheral airways. Current guidelines state that diagnosis and treatment should be guided by symptoms and spirometry. FEV(1) is, however, a poor marker of small airway function and correlates poorly with asthma control and airway inflammation. AIMS To assess the contribution of small airway dysfunction and inflammation in paediatric asthma. A secondary aim was to study the associations between small airway dysfunction, airway inflammation and airway hyper-responsiveness (AHR). METHODS Small airway function was measured as LCI, S(cond) and S(acin), evaluated with the SF(6) multiple breath inert gas washout (MBW) technique, in 47 asthmatic children and 74 healthy controls. Exhaled NO at multiple exhalation flow rates including 50 mL/s (FENO(50)) was assessed to calculate alveolar NO and bronchial NO flux (a surrogate for airway inflammation). AHR was evaluated with isocapnoic dry air hyperventilation challenge in the asthmatic children. RESULTS S(cond) was elevated in 31 (66%) and S(acin) in 18 (38%) of the asthmatic subjects. LCI was increased and FEV(1) decreased in 7 (15%) of the subjects with asthma. Individuals with AHR had higher S(cond) (p = 0.001) and FENO(50) (p < 0.0001) than those without AHR. The levels of FENO(50) and bronchial NO flux were elevated in asthmatic subjects compared with healthy controls. In asthma, S(cond) correlated with FENO(50) (r(s) = 0.42, p = 0.003) and alveolar NO (r(s) = 0.40, p = 0.011), and S(acin) correlated with alveolar NO (r(s) = 0.40, p = 0.015). CONCLUSION Dysfunction of small conducting airways is associated with airway inflammation and hyper-responsiveness in paediatric asthma.
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Affiliation(s)
- Christina Keen
- Department of Paediatrics, University of Gothenburg, Queen Silvia Children's Hospital, SE-416 85 Gothenburg, Sweden.
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Current world literature. Curr Opin Pulm Med 2011; 17:50-3. [PMID: 21116136 DOI: 10.1097/mcp.0b013e3283418f95] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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