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Karlsson LL, Gustafsson LE, Linnarsson D. Pulmonary nitric oxide in astronauts before and during long-term spaceflight. Front Physiol 2024; 15:1298863. [PMID: 38357501 PMCID: PMC10864557 DOI: 10.3389/fphys.2024.1298863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 01/16/2024] [Indexed: 02/16/2024] Open
Abstract
Introduction: During exploratory space flights astronauts risk exposure to toxic planetary dust. Exhaled nitric oxide partial pressure (PENO) is a simple method to monitor lung health by detecting airway inflammation after dust inhalation. The turnover of NO in the lungs is dependent on several factors which will be altered during planetary exploration such as gravity (G) and gas density. To investigate the impacts of these factors on normal PENO, we took measurements before and during a stay at the International Space Station, at both normal and reduced atmospheric pressures. We expected stable PENO levels during the preflight and inflight periods, with lower values inflight. With reduced pressure we expected no net changes of PENO. Material and methods: Ten astronauts were studied during the pre-flight (1 G) and inflight (µG) periods at normal pressure [1.0 ata (atmospheres absolute)], with six of them also monitored at reduced (0.7 ata) pressure and gas density. The average observation period was from 191 days before launch until 105 days after launch. PENO was measured together with estimates of alveolar NO and the airway contribution to the exhaled NO flux. Results: The levels of PENO at 50 mL/s (PENO50) were not stable during the preflight and inflight periods respectively but decreased with time (p = 0.0284) at a rate of 0.55 (0.24) [mean (SD)] mPa per 180 days throughout the observation period, so that there was a significant difference (p < 0.01, N = 10) between gravity conditions. Thus, PENO50 averaged 2.28 (0.70) mPa at 1 G and 1.65 (0.51) mPa during µG (-27%). Reduced atmospheric pressure had no net impact on PENO50 but increased the airway contribution to exhaled NO. Discussion: The time courses of PENO50 suggest an initial airway inflammation, which gradually subsided. Our previous hypothesis of an increased uptake of NO to the blood by means of an expanded gas-blood interface in µG leading to decreased PENO50 is neither supported nor contradicted by the present findings. Baseline PENO50 values for lung health monitoring in astronauts should be obtained not only on ground but also during the relevant gravity conditions and before the possibility of inhaling toxic planetary dust.
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Affiliation(s)
- Lars L. Karlsson
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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2
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Wang J, Wu K, Cheng X, Chen X, Qi Y, Zhao L. The value of concentration of alveolar nitric oxide in diagnosing small airway dysfunction in patients with stable asthma. THE CLINICAL RESPIRATORY JOURNAL 2022; 17:357-363. [PMID: 36508744 DOI: 10.1111/crj.13565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 11/15/2022] [Accepted: 11/20/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Exhaled nitric oxide (FeNO) is a simple, noninvasive, and reproducible test, and FeNO (50 ml/s) is often used to reflect airway inflammation. The peripheral small airway/alveolar nitric oxide (NO) concentration is derived from the output of NO at multiple flow rates. Concentration of alveolar NO (CANO), which has been reported to reflect peripheral small airway inflammation, may be related to parameters that reflect abnormal small airway function. AIM This study aims to investigate the relationship among CANO levels, clinical features, and small airway function-related indicators in patients with stable asthma and to provide a simple method for monitoring small airway function in asthma. DESIGN AND METHODS We recruited 144 patients with well-controlled, stable asthma, including 69 patients with normal small airway function (normal group) and 75 patients with small airway dysfunction (abnormal group). CANO and pulmonary function were measured. RESULTS CANO was significantly higher in the abnormal group ([7.28 ± 3.25] ppb) than the normal group CANO ([2.87 ± 1.50] ppb). FEF25-75%pred ([55.0 ± 16.5]%), FEF50%pred ([46.4 ± 13.2]%), and FEF75%pred ([41.9 ± 13.1]%) in abnormal group were significantly lower compared with normal group ([89.9 ± 7.5]%), ([80.9 ± 6.8]%), and ([73.8 ± 5.0]%). CANO was negatively correlated and FEF25-75%pred, FEF50%pred, and FEF75%pred (r = -0.87, P < 0.001; r = -0.82, P < 0.001; r = -0.78, P < 0.001). CANO was positively correlated with age (r = 0.27, P = 0.001). The area under the ROC curve was 0.875 for CANO. The optimal cutoff point of 5.3 ppb had sensitivity and specificity values of 72% and 92% in diagnosing small airway dysfunction. CONCLUSION CANO has diagnostic value for small airway dysfunction, and the optimal cutoff value is 5.3 ppb. However, the diagnostic evidence is still insufficient, so it still needs further exploration for its value in detecting small airway dysfunction.
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Affiliation(s)
- Jing Wang
- Department of Infectious and Respiratory Critical Care Medicine, Xinxiang Central Hospital, The Fourth Clinical College of Xinxiang Medical University, Xinxiang, China
| | - Ke Wu
- School of Clinical Medicine, Guizhou Medical University, Guiyang, China
| | - Xianliang Cheng
- Department of Respiratory and Critical Care Medicine, Huazhong Fuwai Cardiovascular Disease Hospital, Zhengzhou, China
| | - Xiangsong Chen
- Department of Respiratory and Critical Care Medicine, Huazhong Fuwai Cardiovascular Disease Hospital, Zhengzhou, China
| | - Yanan Qi
- Department of Respiratory and Critical Care Medicine, Huazhong Fuwai Cardiovascular Disease Hospital, Zhengzhou, China
| | - Limin Zhao
- Department of Pulmonary and Critical Care Medicine, Henan Provincial People's Hospital; People's Hospital of Zhengzhou University; People's Hospital of Henan University, Zhengzhou, 450003, China
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Buess A, Van Muylem A, Nonclercq A, Haut B. Modeling of the Transport and Exchange of a Gas Species in Lungs With an Asymmetric Branching Pattern. Application to Nitric Oxide. Front Physiol 2020; 11:570015. [PMID: 33362572 PMCID: PMC7758446 DOI: 10.3389/fphys.2020.570015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 10/21/2020] [Indexed: 01/25/2023] Open
Abstract
Over the years, various studies have been dedicated to the mathematical modeling of gas transport and exchange in the lungs. Indeed, the access to the distal region of the lungs with direct measurements is limited and, therefore, models are valuable tools to interpret clinical data and to give more insights into the phenomena taking place in the deepest part of the lungs. In this work, a new computational model of the transport and exchange of a gas species in the human lungs is proposed. It includes (i) a method to generate a lung geometry characterized by an asymmetric branching pattern, based on the values of several parameters that have to be given by the model user, and a method to possibly alter this geometry to mimic lung diseases, (ii) the calculation of the gas flow distribution in this geometry during inspiration or expiration (taking into account the increased resistance to the flow in airways where the flow is non-established), (iii) the evaluation of the exchange fluxes of the gaseous species of interest between the tissues composing the lungs and the lumen, and (iv) the computation of the concentration profile of the exchanged species in the lumen of the tracheobronchial tree. Even if the model is developed in a general framework, a particular attention is given to nitric oxide, as it is not only a gas species of clinical interest, but also a gas species that is both produced in the walls of the airways and consumed within the alveolar region of the lungs. First, the model is presented. Then, several features of the model, applied to lung geometry, gas flow and NO exchange and transport, are discussed, compared to existing works and notably used to give new insights into experimental data available in the literature, regarding diseases, such as asthma, cystic fibrosis, and chronic obstructive pulmonary disease.
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Affiliation(s)
- Alexandra Buess
- Transfers, Interfaces and Processes, Ecole Polytechnique de Bruxelles, Université Libre de Bruxelles, Brussels, Belgium
| | - Alain Van Muylem
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Antoine Nonclercq
- Bio-, Electro-, and Mechanical Systems (BEAMS), Ecole Polytechnique de Bruxelles, Université Libre de Bruxelles, Brussels, Belgium
| | - Benoit Haut
- Transfers, Interfaces and Processes, Ecole Polytechnique de Bruxelles, Université Libre de Bruxelles, Brussels, Belgium
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4
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Exhaled nitric oxide and its predictive power related to lung function and bronchial inflammation. Biochem Pharmacol 2020; 179:114101. [DOI: 10.1016/j.bcp.2020.114101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/11/2020] [Accepted: 06/12/2020] [Indexed: 11/22/2022]
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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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6
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Pérez-Bogerd S, Michils A, Malinovschi A, Van Muylem A. COPD patients with peripheral airway obstruction reversibility identified by exhaled nitric oxide. J Breath Res 2019; 13:036002. [PMID: 30802891 DOI: 10.1088/1752-7163/ab0a14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
RATIONALE Besides its role as an inflammatory marker in asthma, fractional exhaled nitric oxide (FENO) provides information on the extent of the airway obstruction process through evaluating its change after bronchodilation. OBJECTIVE To investigate whether FENO change after bronchodilation can identify different sites of airway obstruction in COPD patients. METHODS FENO, FEV1 and the slopes (S) of the alveolar plateau of the single breath washout test (SBWT) were measured in 61 stable COPD patients (FEV1 34.5% predicted) before and after the inhalation of 400 μg salbutamol. SBWT used Helium (He), and sulfur-hexafluoride (SF6). Obstruction relief occurring in pre-acinar and intra-acinar small airways is expected to decrease SHe and SSF6, respectively. Indices changes (Δ) after bronchodilation were expressed as a percentage of pre-bronchodilation values. RESULTS FENO stability (∣ΔFENO∣ ≤ 11%) was observed in 19 patients [-2.7(6.7)%] [mean (SD)] (NO = group); ΔFENO > 11% [+37.4(27.7)%] in 20 patients (NO+ group) and ΔFENO < -11% in 22 patients [-31.2(9.8)%] (NO- group). A similar ΔFEV1 (p = 0.583; [+9.4(9.6)%]) was found in the three groups. In NO = and NO+ groups, neither SHe nor SSF6 changed; in NO- both SHe [-12.4(27.5)%, p = 0.007] and SSF6 [-20.2(20.4)%, p < 0.001] significantly decreased. CONCLUSION Different patterns of FENO response to β 2-agonists were observed in COPD most likely depending on the extent of the dilation process. A profile of airway obstruction with an extensive β 2-agonist response down to lung periphery is identified by FENO reduction after acute bronchodilation in 30% of COPD patients. The clinical relevance of this profile requires further investigation.
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Affiliation(s)
- Silvia Pérez-Bogerd
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
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Lázár Z, Horváth P, Puskás R, Gálffy G, Losonczy G, Horváth I, Bikov A. A suitable protocol for measuring alveolar nitric oxide in asthma with differing severity to assess peripheral airways inflammation. J Asthma 2018; 56:584-593. [PMID: 29923757 DOI: 10.1080/02770903.2018.1477957] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Extended nitric oxide (NO) analysis offers the partitioned monitoring of inflammation in central and peripheral airways. Different mathematical models are used to estimate pulmonary NO dynamics in asthma with variable results and limitations. We aimed to establish a protocol for extended NO analysis in patients with differing asthma severity. METHODS Forty patients with stable asthma and 25 matched control subjects were recruited. Exhaled NO was measured at constant flow rates between 10 and 300 mL/s. Twelve controls performed NO measurements weekly for 4 weeks. RESULTS The proportions of patients with technically acceptable measurements at 10-30-50-100-150-200-250-300 mL/s exhalation flow rates were 8-58-100-98-98-95-90-80%, respectively. Alveolar NO (CANO) and total flux of NO in the conducting airways (JawNO) were calculated with the linear method from NO values measured at 100-150-200-250 mL/s exhalation flows. The mean intrasubject bias for JawNO and CANO in controls was 0.16 nL/s and 0.85 ppb, respectively. Both JawNO (1.31/0.83-2.97/vs. 0.70/0.54-0.87/nL/s, p < 0.001) and CANO (4.08/2.63-7.16/vs. 2.42/1.83-2.89/ppb, p < 0.001) were increased in patients with asthma compared to controls. In patients, CANO correlated with RV/TLC (r = 0.58, p < 0.001), FEF25-75% (p = 0.02, r = -0.36) and DL,CO (r = -0.46, p = 0.004). JawNO was not related to lung function parameters. CONCLUSIONS Calculation of alveolar NO concentration with the linear method from values obtained at medium flow rates (100-250 mL/s) is feasible even in asthmatic patients with severe airflow limitation and may provide information on small airways dysfunction in asthma.
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Affiliation(s)
- Zsófia Lázár
- a Department of Pulmonology , Semmelweis University , 1/c Diós árok
| | - Péter Horváth
- a Department of Pulmonology , Semmelweis University , 1/c Diós árok
| | - Rita Puskás
- a Department of Pulmonology , Semmelweis University , 1/c Diós árok
| | - Gabriella Gálffy
- a Department of Pulmonology , Semmelweis University , 1/c Diós árok
| | - György Losonczy
- a Department of Pulmonology , Semmelweis University , 1/c Diós árok
| | - Ildikó Horváth
- b National Korányi Institute of Pulmonology , 1 Pihenő Street , Budapest , Hungary
| | - András Bikov
- a Department of Pulmonology , Semmelweis University , 1/c Diós árok
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8
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Lassmann-Klee PG, Lehtimäki L, Lindholm T, Malmberg LP, Sovijärvi ARA, Piirilä P. Influence of mouthwashes on extended exhaled nitric oxide (F ENO) analysis. Scandinavian Journal of Clinical and Laboratory Investigation 2018; 78:450-455. [PMID: 30345835 DOI: 10.1080/00365513.2018.1497802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Fractional exhaled nitric oxide (FENO) is used to assess eosinophilic inflammation of the airways. FENO values are influenced by the expiratory flow rate and orally produced NO. We measured FENO at four different expiratory flow levels after two different mouthwashes: tap water and carbonated water. Further, we compared the alveolar NO concentration (CANO), maximum airway NO flux (J'awNO) and airway NO diffusion (DawNO) after these two mouthwashes. FENO was measured in 30 volunteers (healthy or asthmatic) with a chemiluminescence NO-analyser at flow rates of 30, 50, 100 and 300 mL/s. A mouthwash was performed before the measurement at every flow rate. The carbonated water mouthwash significantly reduced FENO compared to the tap water mouthwash at all expiratory flows: 50 mL/s (p < .001), 30 mL/s (p = .001), 100 mL/s (p < .001) and 300 mL/s (p = .004). J'awNO was also significantly reduced (p = .017), however, there were no significant differences in CANO and DawNO. In conclusion, a carbonated water mouthwash can significantly reduce oropharyngeal NO compared to a tap water mouthwash at expiratory flows of 30-300 mL/s without affecting the CANO and DawNO. Therefore, mouthwashes need to be taken into account when comparing FENO results.
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Affiliation(s)
- Paul Guenther Lassmann-Klee
- a Unit of Clinical Physiology, Helsinki University Central Hospital and University of Helsinki , Helsinki , Finland
| | - Lauri Lehtimäki
- b Allergy Centre, Tampere University Hospital and Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland
| | - Tuula Lindholm
- c Laboratory of Clinical Physiology , Finnish Institute of Occupational Health , Helsinki , Finland
| | - L Pekka Malmberg
- d Laboratory of Clinical Physiology , Skin and Allergy Hospital , Helsinki , Finland
| | - Anssi Raimo Antero Sovijärvi
- a Unit of Clinical Physiology, Helsinki University Central Hospital and University of Helsinki , Helsinki , Finland
| | - Päivi Piirilä
- a Unit of Clinical Physiology, Helsinki University Central Hospital and University of Helsinki , Helsinki , Finland
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9
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Karamaoun C, Haut B, Van Muylem A. A new role for the exhaled nitric oxide as a functional marker of peripheral airway caliber changes: a theoretical study. J Appl Physiol (1985) 2018; 124:1025-1033. [DOI: 10.1152/japplphysiol.00530.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although considered as an inflammation marker, exhaled nitric oxide (FENO) was shown to be sensitive to airway caliber changes to such an extent that it might be considered as a marker of them. It is thus important to understand how these changes and their localization mechanically affect the total NO flux penetrating the airway lumen ( JawNO), and hence FENO, independently from any inflammatory status change. In this work, a new model was used. It simulates NO production, consumption, and diffusion inside the airway epithelium, NO excretion from the epithelial wall into the airway lumen and, finally, its axial transport by diffusion and convection in the airway lumen. This model may also consider the possible presence of a fluid layer coating the epithelial wall. Simulations were performed. They show the great sensitivity of JawNO to peripheral airway caliber changes. Moreover, FENO shows distinct behaviors, depending on the location of the caliber change. Considering a bronchodilation, absence of FENO change was associated with dilation of central airways, FENO increase with dilation down to pre-acinar small airways, and FENO decrease with intra-acinar dilation due to the amplification of the back diffusion flux. The presence of a fluid layer was also shown to play a significant role in FENO changes. Altogether, the present work theoretically supports that specific FENO changes in acute situations are linked to specifically located airway caliber changes in the lung periphery. This opens the way for a new role for FENO as a functional marker of peripheral airway caliber change. NEW & NOTEWORTHY Using a new model of nitric oxide production and transport, allowing realistic simulation of airway caliber change, the present work theoretically supports that specific changes of the molar fraction of nitric oxide in the exhaled air, occurring without any change in the inflammatory status, are linked to specifically located airway caliber changes in the lung periphery. This opens the way for a new role for FENO as a functional marker of peripheral airway caliber change.
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Affiliation(s)
- Cyril Karamaoun
- Ecole polytechnique de Bruxelles, Transfers Interfaces and Processes, Université libre de Bruxelles, Brussels, Belgium
| | - Benoit Haut
- Ecole polytechnique de Bruxelles, Transfers Interfaces and Processes, Université libre de Bruxelles, Brussels, Belgium
| | - Alain Van Muylem
- Chest Department, Erasme University Hospital, Université libre de Bruxelles, Brussels, Belgium
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Horváth I, Barnes PJ, Loukides S, Sterk PJ, Högman M, Olin AC, Amann A, Antus B, Baraldi E, Bikov A, Boots AW, Bos LD, Brinkman P, Bucca C, Carpagnano GE, Corradi M, Cristescu S, de Jongste JC, Dinh-Xuan AT, Dompeling E, Fens N, Fowler S, Hohlfeld JM, Holz O, Jöbsis Q, Van De Kant K, Knobel HH, Kostikas K, Lehtimäki L, Lundberg J, Montuschi P, Van Muylem A, Pennazza G, Reinhold P, Ricciardolo FLM, Rosias P, Santonico M, van der Schee MP, van Schooten FJ, Spanevello A, Tonia T, Vink TJ. A European Respiratory Society technical standard: exhaled biomarkers in lung disease. Eur Respir J 2017; 49:49/4/1600965. [PMID: 28446552 DOI: 10.1183/13993003.00965-2016] [Citation(s) in RCA: 375] [Impact Index Per Article: 53.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 01/09/2017] [Indexed: 12/19/2022]
Abstract
Breath tests cover the fraction of nitric oxide in expired gas (FeNO), volatile organic compounds (VOCs), variables in exhaled breath condensate (EBC) and other measurements. For EBC and for FeNO, official recommendations for standardised procedures are more than 10 years old and there is none for exhaled VOCs and particles. The aim of this document is to provide technical standards and recommendations for sample collection and analytic approaches and to highlight future research priorities in the field. For EBC and FeNO, new developments and advances in technology have been evaluated in the current document. This report is not intended to provide clinical guidance on disease diagnosis and management.Clinicians and researchers with expertise in exhaled biomarkers were invited to participate. Published studies regarding methodology of breath tests were selected, discussed and evaluated in a consensus-based manner by the Task Force members.Recommendations for standardisation of sampling, analysing and reporting of data and suggestions for research to cover gaps in the evidence have been created and summarised.Application of breath biomarker measurement in a standardised manner will provide comparable results, thereby facilitating the potential use of these biomarkers in clinical practice.
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Affiliation(s)
- Ildiko Horváth
- Dept of Pulmonology, National Korányi Institute of Pulmonology, Budapest, Hungary
| | - Peter J Barnes
- National Heart and Lung Institute, Imperial College London, Royal Brompton Hospital, London, UK
| | | | - Peter J Sterk
- Dept of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Marieann Högman
- Centre for Research & Development, Uppsala University/Gävleborg County Council, Gävle, Sweden
| | - Anna-Carin Olin
- Occupational and Environmental Medicine, Sahlgrenska Academy and University Hospital, Goteborg, Sweden
| | - Anton Amann
- Innsbruck Medical University, Innsbruck, Austria
| | - Balazs Antus
- Dept of Pathophysiology, National Korányi Institute of Pulmonology, Budapest, Hungary
| | | | - Andras Bikov
- Dept of Pulmonology, Semmelweis University, Budapest, Hungary
| | - Agnes W Boots
- Dept of Pharmacology and Toxicology, University of Maastricht, Maastricht, The Netherlands
| | - Lieuwe D Bos
- Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Paul Brinkman
- Dept of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Caterina Bucca
- Biomedical Sciences and Human Oncology, Universita' di Torino, Turin, Italy
| | | | | | - Simona Cristescu
- Dept of Molecular and Laser Physics, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Johan C de Jongste
- Dept of Pediatrics/Respiratory Medicine, Erasmus MC-Sophia Childrens' Hospital, Rotterdam, The Netherlands
| | | | - Edward Dompeling
- Dept of Paediatrics/Family Medicine Research School CAPHRI, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Niki Fens
- Dept of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Stephen Fowler
- Respiratory Research Group, University of Manchester Wythenshawe Hospital, Manchester, UK
| | - Jens M Hohlfeld
- Clinical Airway Research, Fraunhofer Institute of Toxicology and Experimental Medicine (ITEM), Hannover, Germany.,Medizinische Hochschule Hannover, Hannover, Germany
| | - Olaf Holz
- Clinical Airway Research, Fraunhofer Institute of Toxicology and Experimental Medicine (ITEM), Hannover, Germany
| | - Quirijn Jöbsis
- Department of Paediatric Respiratory Medicine, Maastricht University Medical Centre (MUMC+), Maastricht, The Netherlands
| | - Kim Van De Kant
- Dept of Paediatrics/Family Medicine Research School CAPHRI, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Hugo H Knobel
- Philips Research, High Tech Campus 11, Eindhoven, The Netherlands
| | | | | | - Jon Lundberg
- Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Paolo Montuschi
- Pharmacology, Catholic University of the Sacred Heart, Rome, Italy
| | - Alain Van Muylem
- Hopital Erasme Cliniques Universitaires de Bruxelles, Bruxelles, Belgium
| | - Giorgio Pennazza
- Faculty of Engineering, University Campus Bio-Medico, Rome, Italy
| | - Petra Reinhold
- Institute of Molecular Pathogenesis, Friedrich Loeffler Institut, Jena, Germany
| | - Fabio L M Ricciardolo
- Clinic of Respiratory Disease, Dept of Clinical and Biological Sciences, University of Torino, Torino, Italy
| | - Philippe Rosias
- Dept of Paediatrics/Family Medicine Research School CAPHRI, Maastricht University Medical Centre, Maastricht, The Netherlands.,Dept of Pediatrics, Maasland Hospital, Sittard, The Netherlands
| | - Marco Santonico
- Faculty of Engineering, University Campus Bio-Medico, Rome, Italy
| | - Marc P van der Schee
- Dept of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | | | | | - Thomy Tonia
- European Respiratory Society, Lausanne, Switzerland
| | - Teunis J Vink
- Philips Research, High Tech Campus 11, Eindhoven, The Netherlands
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11
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Mason P, Scarpa MC, Guarnieri G, Giordano G, Baraldi E, Maestrelli P. Exhaled nitric oxide dynamics in asthmatic reactions induced by diisocyanates. Clin Exp Allergy 2016; 46:1531-1539. [PMID: 27533788 DOI: 10.1111/cea.12798] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 07/01/2016] [Accepted: 07/05/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND Isocyanate-induced asthmatic reactions are associated with delayed increase in fractional exhaled nitric oxide measured at expiratory flow of 50 mL/s (FeNO50), a biomarker of airway inflammation. The time course of FeNO increase is compatible with the activation of NO synthase, but the origin of NO production in the lung is undetermined. OBJECTIVE The aim of this study was to define the dynamics of airway and alveolar NO during specific inhalation challenge (SIC) with isocyanates and the role of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase. METHODS Spirometry, exhaled NO parameters (FeNO50, bronchial wall NO concentration, NO airway diffusing capacity, NO flux to luminal space, alveolar NO) and ADMA levels in exhaled breath condensate were measured before and at intervals up to 24 h after exposure to isocyanates. The results were compared between 17 SIC-positive and eight SIC-negative subjects. RESULTS A significant FeNO50 increase in SIC-positive subjects was detected 24 h after exposure and was associated with the augmented NO flux from airway wall to the lumen, whereas airway NO diffusion and alveolar NO were not affected. The changes in NO dynamics were specific for the subjects who developed an asthmatic reaction, but were independent from the pattern and magnitude of bronchoconstriction. There was no evidence that exhaled NO is modulated by the changes in ADMA concentration. CONCLUSIONS AND CLINICAL RELEVANCE Because isocyanate-induced increase in FeNO50 was almost exclusively determined by the increase in NO flux, the use of FeNO50 appears adequate to monitor the exhaled NO dynamics during SIC. FeNO50 measurement may provide additional information to spirometry, because bronchoconstriction and airway inflammatory responses are dissociated.
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Affiliation(s)
- P Mason
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - M C Scarpa
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - G Guarnieri
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
| | - G Giordano
- Women's and Children's Health Department, University of Padova, Padova, Italy
| | - E Baraldi
- Women's and Children's Health Department, University of Padova, Padova, Italy
| | - P Maestrelli
- Department of Cardiologic, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
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Different patterns of exhaled nitric oxide response to β2-agonists in asthmatic patients according to the site of bronchodilation. J Allergy Clin Immunol 2015; 137:806-12. [PMID: 26688519 DOI: 10.1016/j.jaci.2015.09.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 09/18/2015] [Accepted: 09/24/2015] [Indexed: 11/20/2022]
Abstract
BACKGROUND In asthmatic patients undergoing airway challenge, fraction of exhaled nitric oxide (FENO) levels decrease after bronchoconstriction. In contrast, model simulations have predicted both decreased and increased FENO levels after bronchodilation, depending on the site of airway obstruction relief. OBJECTIVE We sought to investigate whether β2-agonists might induce divergent effects on FENO values in asthmatic patients as a result of airway obstruction relief occurring at different lung depths. METHODS FENO, FEV1, and the slope of phase III of the single-breath washout test (S) of He (S(He)) and sulfur hexafluoride (S(SF6)) were measured in 68 asthmatic patients before and after salbutamol inhalation. S(He) and S(SF6) decreases reflected preacinar and intra-acinar obstruction relief, respectively. Changes (Δ) were expressed as a percentage from the baseline. RESULTS No FENO change (|ΔFENO| ≤ 10%) was found in 16 patients (mean [SD]: 2.5% [5.2%]; ie, FENO= group); a ΔFENO value of greater than 10% was found in 23 patients (31.7% [20.3%]; ie, the FENO+ group); and a ΔFENO value of less than -10% was found in 29 patients (-31.5% [17.3%]; ie, the FENO- group). All groups had similar ΔFEV1 values. In the FENO= group neither S(He) nor S(SF6) changed, in the FENO+ group only S(He) decreased significantly (-21.8% [SD 28.5%], P = .03), and in the FENO- group both S(He) (-29.8% [24.0%], P < .001) and S(SF6) (-27.2% [23.3%], P < .001) decreased. DISCUSSION Three FENO behaviors were observed in response to β2-agonists: a decrease likely caused by relief of an intra-acinar airway obstruction that we propose reflects amplification of nitric oxide back-diffusion, an increase likely associated with a predominant dilation up to the preacinar airways, and FENO stability when obstruction relief involved predominantly the central airways. In combination, these results suggest a new role for FENO in identifying the site of airway obstruction in asthmatic patients.
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Corcuera-Elosegui P, Sardón-Prado O, Aldasoro-Ruiz A, Korta-Murua J, Mintegui-Aramburu J, Emparanza-Knorr JI, Pérez-Yarza EG. Inflammatory Patterns in Asthmatic Children Based on Alveolar Nitric Oxide Determination. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.arbr.2015.02.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Hodgson D, Anderson J, Reynolds C, Meakin G, Bailey H, Pavord I, Shaw D, Harrison T. A randomised controlled trial of small particle inhaled steroids in refractory eosinophilic asthma (SPIRA). Thorax 2015; 70:559-65. [PMID: 25858909 PMCID: PMC4453493 DOI: 10.1136/thoraxjnl-2014-206481] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 03/15/2015] [Indexed: 11/04/2022]
Abstract
BACKGROUND Some patients with refractory asthma have evidence of uncontrolled eosinophilic inflammation in the distal airways. While traditional formulations of inhaled steroids settle predominantly in the large airways, newer formulations with an extra-fine particle size have a more peripheral pattern of deposition. Specifically treating distal airway inflammation may improve asthma control. METHODS 30 patients with refractory asthma despite high dose inhaled corticosteroids were identified as having persistent airway eosinophilia. Following 2 weeks of prednisolone 30 mg, patients demonstrating an improvement in asthma control were randomised to receive either ciclesonide 320 µg twice daily or placebo in addition to usual maintenance therapy for 8 weeks. The primary outcome measure was sputum eosinophil count at week 8. Alveolar nitric oxide was measured as a marker of distal airway inflammation. RESULTS There was continued suppression of differential sputum eosinophil counts with ciclesonide (median 2.3%) but not placebo (median 4.5%) though the between-group difference was not significant. When patients who had changed their maintenance prednisolone dose during the trial were excluded the difference between groups was significant (1.4% vs 4.5%, p=0.028). Though alveolar nitric oxide decreased with ciclesonide the value did not reach statistical significance. CONCLUSIONS These data demonstrate that patients with ongoing eosinophilic inflammation are not truly refractory, and that suppression of airway eosinophilia may be maintained with additional inhaled corticosteroid. Further work is needed with a focus on patient-orientated outcome measures such as exacerbation rate, with additional tests of small airway function. TRIAL REGISTRATION NUMBER NCT01171365. Protocol available at http://www.clinicaltrials.gov.
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Affiliation(s)
- David Hodgson
- Nottingham Respiratory Research Unit, University of Nottingham, Nottingham, UK
| | - John Anderson
- Nottingham Respiratory Research Unit, University of Nottingham, Nottingham, UK
| | - Catherine Reynolds
- Nottingham Respiratory Research Unit, University of Nottingham, Nottingham, UK
| | - Garry Meakin
- Nottingham Respiratory Research Unit, University of Nottingham, Nottingham, UK
| | - Helen Bailey
- Nottingham Respiratory Research Unit, University of Nottingham, Nottingham, UK
| | - Ian Pavord
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Dominick Shaw
- Nottingham Respiratory Research Unit, University of Nottingham, Nottingham, UK
| | - Tim Harrison
- Nottingham Respiratory Research Unit, University of Nottingham, Nottingham, UK
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Corcuera-Elosegui P, Sardón-Prado O, Aldasoro-Ruiz A, Korta-Murua J, Mintegui-Aramburu J, Emparanza-Knorr JI, Pérez-Yarza EG. Inflammatory patterns in asthmatic children based on alveolar nitric oxide determination. Arch Bronconeumol 2014; 51:279-84. [PMID: 25311845 DOI: 10.1016/j.arbres.2014.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 06/18/2014] [Accepted: 07/01/2014] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Nitric oxide (NO) levels can be measured at proximal (maximum airway NO flux [J'aw(NO)]) and distal (alveolar NO concentration [C(ANO)]) levels. Four inflammatory patterns have been described in asthmatic individuals, although their relevance has not been well established. The objective was to determine J'aw(NO) and C(ANO) in order to establish four inflammatory categories in asthmatics. MATERIAL AND METHODS Cross-sectional study of a sample consisting of healthy and asthmatic children. Exhaled NO was determined at multiple flows. J'aw(NO) and C(ANO) were obtained according to the two-compartment model. The asthma control questionnaire (ACQ) and spirometry were administered to asthmatic children. Patients were categorized as type I (normal J'aw(NO) and C(ANO)), type II (elevated J'aw(NO) and normal C(ANO)), type III (elevated J'aw(NO) and C(ANO)) and type IV (normal J'aw(NO) and elevated C(ANO)). Correlation between FE(NO,50), J'aw(NO) and C(ANO) was analyzed using Spearman's R Correlation Test. Analysis of variance and paired comparisons were performed using the Bonferroni correction. RESULTS One hundred sixty-two children were studied, of whom 49 (32.23%) were healthy controls and 103 (67.76%) asthmatics. In the control subjects, FE(NO,50) (ppb)(median and range) was 11.5 (1.6 to 27.3), J'aw(NO) (pl/s) was 516 (98.3 to 1470) and C(ANO) (ppb) was 2.2 (0.1 to 4.5). Forty-four (42.7%) of the asthmatic participants were categorized as type I, 41 (39.8%) as type II, 14 (13.5%) as type III and 4 (3.88%) as type IV. Good correlation was observed between J'aw(NO) and FE(NO,50) (r=0.97). There was no association between J'aw(NO) and C(ANO). FEV1/FVC decreased significantly in type III (mean 79.8±7.5). Morbidity was significantly higher in types III and IV. CONCLUSIONS Normal values obtained are similar to those previously reported. Asthmatics with high C(ANO) showed higher morbidity. No correlation was found between proximal and distal inflammation.
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Affiliation(s)
- Paula Corcuera-Elosegui
- Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España
| | - Olaia Sardón-Prado
- Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España; Departamento de Pediatría, Universidad del País Vasco (UPV/EHU), San Sebastián, Guipúzcoa, España.
| | - Ane Aldasoro-Ruiz
- Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España
| | - Javier Korta-Murua
- Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España; Departamento de Pediatría, Universidad del País Vasco (UPV/EHU), San Sebastián, Guipúzcoa, España
| | - Javier Mintegui-Aramburu
- Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España
| | - José I Emparanza-Knorr
- Unidad de Epidemiología (CIBER-ESP), Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España
| | - Eduardo G Pérez-Yarza
- Sección de Neumología Infantil, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, España; Departamento de Pediatría, Universidad del País Vasco (UPV/EHU), San Sebastián, Guipúzcoa, España; Centro de Investigación Biomédica en Red, Enfermedades Respiratorias (CIBERES), San Sebastián, Guipúzcoa, España
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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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Sardón O, Corcuera P, Aldasoro A, Korta J, Mintegui J, Emparanza JI, Pérez-Yarza EG. Alveolar nitric oxide and its role in pediatric asthma control assessment. BMC Pulm Med 2014; 14:126. [PMID: 25090994 PMCID: PMC4124482 DOI: 10.1186/1471-2466-14-126] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 07/29/2014] [Indexed: 11/17/2022] Open
Abstract
Background Nitric oxide can be measured at multiple flow rates to determine proximal (maximum airway nitric oxide flux; JawNO) and distal inflammation (alveolar nitric oxide concentration; CANO). The main aim was to study the association among symptoms, lung function, proximal (maximum airway nitric oxide flux) and distal (alveolar nitric oxide concentration) airway inflammation in asthmatic children treated and not treated with inhaled glucocorticoids. Methods A cross-sectional study with prospective data collection was carried out in a consecutive sample of girls and boys aged between 6 and 16 years with a medical diagnosis of asthma. Maximum airway nitric oxide flux and alveolar nitric oxide concentration were calculated according to the two-compartment model. In asthmatic patients, the asthma control questionnaire (CAN) was completed and forced spirometry was performed. In controls, differences between the sexes in alveolar nitric oxide concentration and maximum airway nitric oxide flux and their correlation with height were studied. The correlation among the fraction of exhaled NO at 50 ml/s (FENO50), CANO, JawNO, forced expiratory volume in 1 second (FEV1) and the CAN questionnaire was measured and the degree of agreement regarding asthma control assessment was studied using Cohen’s kappa. Results We studied 162 children; 49 healthy (group 1), 23 asthmatic participants without treatment (group 2) and 80 asthmatic patients treated with inhaled corticosteroids (group 3). CANO (ppb) was 2.2 (0.1-4.5), 3 (0.2-9.2) and 2.45 (0.1-24), respectively. JawNO (pl/s) was 516 (98.3-1470), 2356.67 (120–6110) and 1426 (156–11805), respectively. There was a strong association (r = 0.97) between FENO50 and JawNO and the degree of agreement was very good in group 2 and was good in group 3. There was no agreement or only slight agreement between the measures used to monitor asthma control (FEV1, CAN questionnaire, CANO and JawNO). Conclusions The results for CANO and JawNO in controls were similar to those found in other reports. There was no agreement or only slight agreement among the three measure instruments analyzed to assess asthma control. In our sample, no additional information was provided by CANO and JawNO.
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Affiliation(s)
- Olaia Sardón
- Division of Pediatric Respiratory Medicine, Hospital Universitario Donostia, Avda, Dr, Beguiristain número 118, San Sebastian, Guipúzcoa CP 20014, Spain.
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Heijkenskjöld-Rentzhog C, Nordvall L, Janson C, Borres MP, Alving K, Malinovschi A. Alveolar and exhaled NO in relation to asthma characteristics--effects of correction for axial diffusion. Allergy 2014; 69:1102-11. [PMID: 24894594 DOI: 10.1111/all.12430] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2014] [Indexed: 02/05/2023]
Abstract
BACKGROUND Inflammation in the small airways might contribute to incomplete asthma disease control despite intensive treatment in some subgroups of patients. Exhaled NO (FeNO) is a marker of inflammation in asthma and the estimated NO contribution from small airways (CalvNO ) is believed to reflect distal inflammation. Recent studies recommend adjustments of CalvNO for trumpet model and axial diffusion (TMAD-adj). This study aimed to investigate the clinical correlates of CalvNO , both TMAD-adjusted and unadjusted. METHODS Asthma symptoms, asthma control, lung function, bronchial responsiveness, blood eosinophils, atopy and treatment level were assessed in 410 subjects, aged 10-35 years. Exhaled NO was measured at different flow-rates and CalvNO calculated, with TMAD-adjustment according to Condorelli. RESULTS Trumpet model and axial diffusion-adjusted CalvNO was not related to daytime wheeze (P = 0.27), FEF50 (P = 0.23) or bronchial responsiveness (P = 0.52). On the other hand, unadjusted CalvNO was increased in subjects with daytime wheeze (P < 0.001), decreased FEF50 (P = 0.02) and with moderate-to-severe compared to normal bronchial responsiveness (P < 0.001). All these characteristics correlated with increased FeNO (all P < 0.05). Unadjusted CalvNO was positively related to bronchial NO flux (J'awNO ) (r = 0.22, P < 0.001) while TMAD-adjCalvNO was negatively related to J'awNO (r = -0.38, P < 0.001). CONCLUSIONS Adjusted CalvNO was not associated with any asthma characteristics studied in this large asthma cohort. However, both FeNO and unadjusted CalvNO related to asthma symptoms, lung function and bronchial responsiveness. We suggest a potential overadjustment by current TMAD-corrections, validated in healthy or unobstructed asthmatics. Further studies assessing axial diffusion in asthmatics with different degrees of airway obstruction and the validity of proposed TMAD-corrections are warranted.
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Affiliation(s)
| | - L. Nordvall
- Department of Women's and Children's Health; Uppsala University; Uppsala Sweden
| | - C. Janson
- Department of Medical Sciences: Respiratory Medicine and Allergology; Uppsala University; Uppsala Sweden
| | - M. P. Borres
- Department of Women's and Children's Health; Uppsala University; Uppsala Sweden
| | - K. Alving
- Department of Women's and Children's Health; Uppsala University; Uppsala Sweden
| | - A. Malinovschi
- Department of Medical Sciences: Clinical Physiology; Uppsala University; Uppsala Sweden
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Modig L, Dahgam S, Olsson D, Nyberg F, Wass K, Forsberg B, Olin AC. Short-term exposure to ozone and levels of exhaled nitric oxide. Epidemiology 2014; 25:79-87. [PMID: 24213146 DOI: 10.1097/ede.0000000000000002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Adverse effects of air pollution include respiratory inflammation. A few epidemiologic studies have shown elevations in the fraction of exhaled nitric oxide, a marker of airway inflammation, after exposure to traffic-related pollutants. METHODS We examined whether short-term exposures to ozone (O3), oxides of nitrogen (NOx), or particulate matter <10 μm (PM10) were associated with proximal and distal airway inflammation. The study included 5841 randomly selected Swedish adults from 25 to 75 years of age. Fraction of exhaled nitrogen was measured at two flow rates: 50 ml/s representing the proximal airways and 270 ml/s representing the distal airways. Air pollution data were obtained from an urban monitoring site. We applied linear regression to estimate short-term associations of O3, NOx, and PM10 with fractions of exhaled NO at 50 and 270 ml/s. RESULTS An interquartile range increase in 120-hour average O3 levels was associated with a 5.1% (95% confidence interval = 1.7% to 8.5%) higher level of fraction of exhaled NO at 270 ml/s and 3.6% (-0.4% to 3.4%) higher level of the fraction of exhaled NO at 50 ml/s. For NOx, a small effect was seen for the 24-hour average on the fraction of exhaled NO at 270 ml/s, while for PM10 no clear effects were seen. There was a tendency for a weaker effect of ozone and a stronger effect of NOx in subjects with asthma. CONCLUSIONS Exposure to O3 was associated with a marker of distal airway inflammation, while the association was less obvious for inflammation of the proximal airways.
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Affiliation(s)
- Lars Modig
- From the aOccupational and Environmental Medicine, Department of Public Health and Clinical Medicine, University of Umeå, Umeå, Sweden; bOccupational and Environmental Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden; and cAstraZeneca R&D, Mölndal, Sweden
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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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Högman M, Thornadtsson A, Hedenstierna G, Meriläinen P. A practical approach to the theoretical models to calculate NO parameters of the respiratory system. J Breath Res 2014; 8:016002. [PMID: 24565997 DOI: 10.1088/1752-7155/8/1/016002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Expired nitric oxide (NO) is used as a biomarker in different respiratory diseases. The recommended flow rate of 50 mL s⁻¹ (F(E)NO₀.₀₅) does not reveal from where in the lung NO production originated. Theoretical models of NO transfer from the respiratory system, linear or nonlinear approaches, have therefore been developed and applied. These models can estimate NO from distal lung (alveolar NO) and airways (bronchial flux). The aim of this study was to show the limitation in exhaled flow rate for the theoretical models of NO production in the respiratory system, linear and nonlinear models. Subjects (n = 32) exhaled at eight different flow rates between 10-350 mL s⁻¹ for the theoretical protocols. Additional subjects (n = 32) exhaled at tree flow rates (20, 100 and 350 mL s⁻¹) for the clinical protocol. When alveolar NO is calculated using high flow rates with the linear model, correction for axial back diffusion becomes negligible, -0.04 ppb and bronchial flux enhanced by 1.27. With Högman and Meriläinen algorithm (nonlinear model) the corrections factors can be understood to be embedded, and the flow rates to be used are ≤20, 100 and ≥350 mL s⁻¹. Applying these flow rates in a clinical setting any F(E)NO can be calculated necessitating fewer exhalations. Hence, measured F(E)NO₀.₀₅ 12.9 (7.2-18.7) ppb and calculated 12.9 (6.8-18.7) ppb. In conclusion, the only possibility to avoid inconsistencies between research groups is to use the measured NO values as such in modelling, and apply tight quality control to accuracies in both NO concentration and exhaled flow measurements.
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Affiliation(s)
- M Högman
- Centre for Research and Development, Uppsala University/County Council of Gävleborg, SE 801 88 Gävle, Sweden. Department of Medical Sciences, Lung Medicine and Allergology, Uppsala University, Sweden
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Eckel SP, Baumbach J, Hauschild AC. On the importance of statistics in breath analysis--hope or curse? J Breath Res 2014; 8:012001. [PMID: 24565974 DOI: 10.1088/1752-7155/8/1/012001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Sandrah P Eckel
- Division of Biostatistics, Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA
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Haccuria A, Michils A, Michiels S, Van Muylem A. Exhaled nitric oxide: a biomarker integrating both lung function and airway inflammation changes. J Allergy Clin Immunol 2014; 134:554-9. [PMID: 24522091 DOI: 10.1016/j.jaci.2013.12.1070] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 11/28/2013] [Accepted: 12/10/2013] [Indexed: 10/25/2022]
Abstract
BACKGROUND The increased fraction of exhaled nitric oxide (Feno) values observed in asthmatic patients are thought to reflect increased airway inflammation. However, Feno values can be affected by airway caliber reduction, representing a bias when using Feno values to assess asthma control. OBJECTIVE We sought to determine the effect of changes in both airway caliber and inflammation on Feno values using the allergen challenge model. METHODS FEV1 and Feno values were measured during early airway responses (EARs) and late airway responses after challenge with house dust mite allergens in 15 patients with mild allergic asthma. Helium and sulfur hexafluoride (SF6) phase III expired concentration slopes (SHe and SSF6, respectively) from single-breath washout tests were measured to identify sites of airway constriction. RESULTS In EARs, FEV1 and Feno value decreases reached 36.8% and 22%, respectively (P < .001). ΔSHe was greater than ΔSSF6 (+189.4% vs +82.2%, P = .001). In late airway responses FEV1 and Feno value decreases reached 31.7% and 28.7%, respectively (P < .001), with the same ΔSHe and ΔSSF6 pattern (+155.8% vs +76%, P = .001). Eight hours after the EAR, FEV1 was still decreased (P < .001), whereas Feno values had returned to baseline. At 24 hours, FEV1 had returned to baseline, with Feno values increased by 38.7% (P = .04). CONCLUSION In patients with mild allergic asthma, airway caliber changes modulate changes in Feno values resulting from airway inflammation. Therefore Feno should no longer be considered solely an inflammation biomarker but rather a biomarker that integrates both airway inflammation and lung function changes. Furthermore, early and late phases resulting from allergen exposure were shown to involve similar lung regions.
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Affiliation(s)
- Amaryllis Haccuria
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium; Chest Department, Centre Hospitalier Régional de Namur, Namur, Belgium
| | - Alain Michils
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Sébastien Michiels
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Alain Van Muylem
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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Eckel SP, Linn WS, Berhane K, Rappaport EB, Salam MT, Zhang Y, Gilliland FD. Estimation of parameters in the two-compartment model for exhaled nitric oxide. PLoS One 2014; 9:e85471. [PMID: 24465571 PMCID: PMC3894971 DOI: 10.1371/journal.pone.0085471] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 11/27/2013] [Indexed: 01/13/2023] Open
Abstract
The fractional concentration of exhaled nitric oxide (FeNO) is a biomarker of airway inflammation that is being increasingly considered in clinical, occupational, and epidemiological applications ranging from asthma management to the detection of air pollution health effects. FeNO depends strongly on exhalation flow rate. This dependency has allowed for the development of mathematical models whose parameters quantify airway and alveolar compartment contributions to FeNO. Numerous methods have been proposed to estimate these parameters using FeNO measured at multiple flow rates. These methods—which allow for non-invasive assessment of localized airway inflammation—have the potential to provide important insights on inflammatory mechanisms. However, different estimation methods produce different results and a serious barrier to progress in this field is the lack of a single recommended method. With the goal of resolving this methodological problem, we have developed a unifying framework in which to present a comprehensive set of existing and novel statistical methods for estimating parameters in the simple two-compartment model. We compared statistical properties of the estimators in simulation studies and investigated model fit and parameter estimate sensitivity across methods using data from 1507 schoolchildren from the Southern California Children's Health Study, one of the largest multiple flow FeNO studies to date. We recommend a novel nonlinear least squares model with natural log transformation on both sides that produced estimators with good properties, satisfied model assumptions, and fit the Children's Health Study data well.
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Affiliation(s)
- Sandrah P. Eckel
- Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
| | - William S. Linn
- Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Kiros Berhane
- Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Edward B. Rappaport
- Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Muhammad T. Salam
- Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Yue Zhang
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States of America
| | - Frank D. Gilliland
- Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America
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van Mastrigt E, de Groot RCA, van Kesteren HW, Vink ATJ, de Jongste JC, Pijnenburg MWH. Tidal breathing FeNO measurements: a new algorithm. Pediatr Pulmonol 2014; 49:15-20. [PMID: 23401372 DOI: 10.1002/ppul.22782] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 12/22/2012] [Accepted: 12/22/2012] [Indexed: 11/05/2022]
Abstract
OBJECTIVE International guidelines recommend measuring fractional exhaled nitric oxide (FeNO) during a single slow exhalation with a constant flow of 50 ml/sec. We developed a new algorithm to compute FeNO at 50 ml/sec from tidal breathing measurements. The main objective is to assess the correlation and agreement of this algorithm with the conventional single breath FeNO measurements. METHODS We recruited children aged 6-18 years, who performed both a single breath and a tidal breathing FeNO measurement in random order. Both maneuvers were performed on the Eco Medics NO-analyser (Eco Physics AG, Duernten, Switzerland). RESULTS We included 109 patients between January 2011 and April 2011. Geometric mean (95% CI) FeNO values did not differ significantly between single breath and tidal breathing technique: 21.0 (17.7-24.8) ppb and 20.0 (17.0-23.6) ppb (P = 0.18), respectively. We found an excellent intraclass correlation coefficient of 0.96 (0.94-0.97) and moderate agreement with a mean difference of 4% (95% limits of agreement -43% and +90%). CONCLUSION Tidal breathing FeNO values could be transformed with a new algorithm to match single breath FeNO at a constant flow of 50 ml/sec. This algorithm opens the way to standardized FeNO measurements in preschool children and uncooperative patients.
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Affiliation(s)
- Esther van Mastrigt
- Department of Pediatric Respiratory Medicine, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands
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Abstract
During inspiration and expiration, gases traverse the conducting airways as they are transported between the environment and the alveolar region of the lungs. The term "conducting" airways is used broadly as the airway tree is thought largely to provide a conduit for the respiratory gases, oxygen and carbon dioxide. However, despite a significantly smaller surface area, and thicker barrier separating the gas phase from the blood when compared to the alveolar region, the airway tree can participate in gas exchange under special conditions such as high water solubility, high chemical reactivity, or production of the gas within the airway wall tissue. While these conditions do not apply to the respiratory gases, other gases demonstrate substantial exchange of the airways and are of particular importance to the inflammatory response of the lungs, the medical-legal field, occupational health, metabolic disorders, or protection of the delicate alveolar membrane. Given the significant structural differences between the airways and the alveolar region, the physical determinants that control airway gas exchange are unique and require different models (both experimental and mathematical) to explore. Our improved physiological understanding of airway gas exchange combined with improved analytical methods to detect trace compounds in the exhaled breath provides future opportunities to develop new exhaled biomarkers that are characteristic of pulmonary and systemic conditions.
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Affiliation(s)
- Steven C George
- Department of Biomedical Engineering, University of California, Irvine, California, USA.
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27
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Scichilone N, Battaglia S, Bellia V. Reply: To PMID 23639306. J Allergy Clin Immunol 2013; 132:1256. [PMID: 24021573 DOI: 10.1016/j.jaci.2013.07.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Accepted: 07/09/2013] [Indexed: 11/19/2022]
Affiliation(s)
- Nicola Scichilone
- Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S.), Sezione di Pneumologia, University of Palermo, Palermo, Italy.
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Lipworth B. Uncorrected nitric oxide levels in mild asthmatics produce flawed interpretation. J Allergy Clin Immunol 2013; 132:1255. [PMID: 24012210 DOI: 10.1016/j.jaci.2013.07.043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 06/14/2013] [Accepted: 07/08/2013] [Indexed: 10/26/2022]
Affiliation(s)
- Brian Lipworth
- Asthma and Allergy Research Group, Ninewells Hospital, University of Dundee, United Kingdom.
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Usefulness of alveolar nitric oxide measurement in asthma: still debated. J Allergy Clin Immunol 2013; 132:1255-6. [PMID: 24012211 DOI: 10.1016/j.jaci.2013.07.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 07/08/2013] [Indexed: 11/23/2022]
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30
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Linn WS, Rappaport EB, Eckel SP, Berhane KT, Zhang Y, Salam MT, Bastain TM, Gilliland FD. Multiple-flow exhaled nitric oxide, allergy, and asthma in a population of older children. Pediatr Pulmonol 2013; 48:885-96. [PMID: 23687084 PMCID: PMC3748140 DOI: 10.1002/ppul.22708] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 09/24/2012] [Indexed: 11/12/2022]
Abstract
UNLABELLED "Extended" (multiple-flow) measurements of exhaled nitric oxide (FeNO) potentially can distinguish proximal and distal airway inflammation, but have not been evaluated previously in large populations. We performed extended NO testing within a longitudinal study of a school-based population, to relate bronchial flux (J'awNO) and peripheral NO concentration (CalvNO) estimates with respiratory health status determined from questionnaires. We measured FeNO at 30, 50, 100, and 300 ml/sec in 1,640 subjects aged 12-15 from eight communities, then estimated J'awNO and CalvNO from linear and nonlinear regressions of NO output versus flow. J'awNO, as well as FeNO at all flows, showed influences of asthma, allergy, Asian or African ancestry, age, and height (positive), and of weight (negative), generally corroborating past findings. By contrast, CalvNO results were inconsistent across different extended NO regression models, and appeared more sensitive to small measurement artifacts. CONCLUSIONS Extended NO testing is feasible in field surveys of young populations. In interpreting results, size, age, and ethnicity require attention, as well as instrumental and environmental artifacts. J'awNO and conventional FeNO provide similar information, probably reflecting proximal airway inflammation. CalvNO may give additional information relevant to peripheral airway, alveolar, or systemic pathology. However, it needs additional research, including testing of populations with independently verifiable peripheral or systemic pathology, to optimize measurement technique and interpretation.
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Affiliation(s)
- William S Linn
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089, USA.
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Williamson PA, Short PM, Vaidyanathan S, Lipworth BJ. Inhaled and systemic corticosteroid response in severe asthma assessed by alveolar nitric oxide: a randomized crossover pilot study of add-on therapy. Br J Clin Pharmacol 2013; 75:93-102. [PMID: 22568828 DOI: 10.1111/j.1365-2125.2012.04319.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
AIMS Alveolar nitric oxide (CA(NO)) is a potential biomarker of small airway inflammation. We investigated effects on CA(NO) of the addition of coarse and fine particle inhaled corticosteroids to standard therapy in severe asthma. METHODS Severe asthmatics taking ≥1600 µg day(-1) budesonide or equivalent performed a randomized open-label crossover study. Subjects with FEV(1) < 80%, gas trapping and CA(NO) ≥2 ppb entered a 6 week dose-ramp run-in of fluticasone/salmeterol(FPSM) 250/50 µg twice daily for 3 weeks, then 500/50 µg twice daily for 3 weeks. Patients then received additional HFA-beclomethasone diproprionate (BDP) 200 µg twice daily or FP 250 µg twice daily for 3 weeks in a crossover. Participants then received prednisolone(PRED) 25 mg day(-1) for 1 week. Nitric oxide, lung function, mannitol challenge, systemic inflammatory markers and urinary cortisol were measured. RESULTS Fifteen completed per protocol: mean (SD) age 51 (12) years, FEV(1) 58 (13)% predicted, residual volume 193 (100)% predicted and mannitol(PD10) 177 (2.8) µg. There was no significant difference between FPSM and add-on therapy for CA(NO). FPSM/BDP and FPSM/PRED suppressed broncial flux (Jaw(NO)) and FE(NO) compared with FPSM alone, but there was no significant difference between FPSM/BDP and FPSM/FP. ECP, e-selectin and ICAM-1 were suppressed by FPSM/PRED compared with FPSM and FPSM/FP but not FPSM/BDP. Plasma cortisol was significantly suppressed by FPSM/PRED. CONCLUSION In severe asthma, CA(NO) is insensitive to changes in dose and delivery of inhaled corticosteroids and is not suppressed by systemic corticosteroids. Additional inhaled HFA-BDP reduced FE(NO) and Jaw(NO) without adrenal suppression. There was a trend to reduction in FE(NO) and Jaw(NO) with additional FP but this did not reach statistical significance. PRED reduced FE(NO) and Jaw(NO) with suppression of systemic inflammatory markers and urinary cortisol.
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Affiliation(s)
- Peter A Williamson
- Asthma and Allergy Research Group, Division of Medical Sciences, University of Dundee, Dundee, Scotland, UK
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Faiss R, Pialoux V, Sartori C, Faes C, Dériaz O, Millet GP. Ventilation, oxidative stress, and nitric oxide in hypobaric versus normobaric hypoxia. Med Sci Sports Exerc 2013; 45:253-60. [PMID: 22895381 DOI: 10.1249/mss.0b013e31826d5aa2] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE Slight differences in physiological responses and nitric oxide (NO) have been reported at rest between hypobaric hypoxia (HH) and normobaric hypoxia (NH) during short exposure.Our study reports NO and oxidative stress at rest and physiological responses during moderate exercise in HH versus NH. METHODS Ten subjects were randomly exposed for 24 h to HH (3000 m; FIO2, 20.9%; BP, 530 ± 6 mm Hg) or to NH (FIO2, 14.7%; BP, 720 ± 1 mm Hg). Before and every 8 h during the hypoxic exposures, pulse oxygen saturation (SpO2), HR, and gas exchanges were measured during a 6-min submaximal cycling exercise. At rest, the partial pressure of exhaled NO, blood nitrate and nitrite (NOx), plasma levels of oxidative stress, and pH levels were additionally measured. RESULTS During exercise, minute ventilation was lower in HH compared with NH (-13% after 8 h, P < 0.05). End-tidal CO2 pressure was lower (P < 0.01) than PRE both in HH and NH but decreased less in HH than that in NH (-25% vs. -37%, P < 0.05).At rest, exhaled NO and NOx decreased in HH (-46% and -36% after 24 h, respectively, P < 0.05) whereas stable in NH. By contrast, oxidative stress was higher in HH than that in NH after 24 h (P < 0.05). The plasma pH level was stable in HH but increased in NH (P < 0.01). When compared with prenormoxic values, SpO2, HR, oxygen consumption, breathing frequency, and end-tidal O2 pressure showed similar changes in HH and NH. CONCLUSION Lower ventilatory responses to a similar hypoxic stimulus during rest and exercise in HH versus NH were sustained for 24 h and associated with lower plasma pH level, exaggerated oxidative stress, and impaired NO bioavailability.
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Affiliation(s)
- Raphael Faiss
- Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.
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Switching from salmeterol/fluticasone to formoterol/budesonide combinations improves peripheral airway/alveolar inflammation in asthma. Pulm Pharmacol Ther 2013; 27:52-6. [PMID: 23583566 DOI: 10.1016/j.pupt.2013.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 03/30/2013] [Accepted: 04/02/2013] [Indexed: 11/20/2022]
Abstract
BACKGROUND Combination therapy with an inhaled corticosteroid (ICS) and a long-acting β2-agonist (LABA) in a single inhaler is the mainstay of asthma management. We previously showed that switching from salmeterol/fluticasone combination (SFC) 50/250 μg bid to a fixed-dose formoterol/budesonide combination (FBC) 9/320 μg bid improved asthma control and pulmonary functions, but not fractional exhaled nitric oxide (FeNO), in patients with asthma not adequately controlled under the former treatment regimen. OBJECTIVE To assess whether switching from SFC to FBC improves peripheral airway/alveolar inflammation in asthma (UMIN000009619). METHODS Subjects included 66 patients with mild to moderate asthma receiving SFC 50/250 μg bid for more than 8 weeks. Patients were randomized into FBC 9/320 μg bid or continued the same dose of SFC for 12 weeks. Asthma Control Questionnaire, 5-item version (ACQ5) score, peak expiratory flow, spirometry, FeNO, alveolar NO concentration (CANO), and maximal NO flux in the conductive airways (J'awNO) were measured. RESULTS Sixty-one patients completed the study. The proportion of patients with an improvement in ACQ5 was significantly higher in the FBC group than in the SFC group (51.6% vs 16.7%, respectively, p = 0.003). A significant decrease in CANO was observed in the FBC group (from 8.8 ± 9.2 ppb to 4.0 ± 2.6 ppb; p = 0.007) compared to the SFC group (from 7.4 ± 7.8 ppb to 6.4 ± 5.0 ppb; p = 0.266) although there was no significant difference in the changes in pulmonary functions between the 2 groups. Similar significant differences were found in the CANO corrected for the axial back diffusion of NO (FBC, from 6.5 ± 8.2 ppb to 2.3 ± 2.5 ppb; and SFC, from 4.3 ± 5.3 ppb to 3.9 ± 4.3 ppb). There was no difference in the changes in FeNO or J'awNO between the 2 groups. CONCLUSIONS Switching therapy from SFC to FBC improves asthma control and peripheral airway/alveolar inflammation even though there is no improvement in pulmonary functions, and FeNO in asthmatic patients.
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Cristescu SM, Mandon J, Harren FJM, Meriläinen P, Högman M. Methods of NO detection in exhaled breath. J Breath Res 2013; 7:017104. [PMID: 23445766 DOI: 10.1088/1752-7155/7/1/017104] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
There is still an unexplored potential for exhaled nitric oxide (NO) in many clinical applications. This study presents an overview of the currently available methods for monitoring NO in exhaled breath and the use of the modelling of NO production and transport in the lung in clinical practice. Three technologies are described, namely chemiluminescence, electrochemical sensing and laser-based detection with their advantages and limitations. Comparisons are made in terms of sensitivity, time response, size, costs and suitability for clinical purposes. The importance of the flow rate for NO sampling is discussed from the perspective of the recent recommendations for standardized procedures for online and offline NO measurement. The measurement of NO at one flow rate, such as 50 ml s(-1), can neither determine the alveolar site/peripheral contribution nor quantify the difference in NO diffusion from the airways walls. The use of NO modelling (linear or non-linear approach) can solve this problem and provide useful information about the source of NO. This is of great value in diagnostic procedures of respiratory diseases and in treatment with anti-inflammatory drugs.
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Affiliation(s)
- S M Cristescu
- Life Science Trace Gas Facility, Molecular and Laser Physics, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands.
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Abstract
OBJECTIVE Studies of fractional exhaled NO (FeNO) or induced sputum are now well standardized and the exponential increase in publications about exhaled breath condensate reflects growing interest in a noninvasive diagnosis of pulmonary diseases in occupational medicine. METHODS This review describes current techniques (FeNO, induced sputum, and exhaled breath condensate) for the study of inflammation and oxidative stress biomarkers. RESULTS These biomarkers are FeNO, cytokines, H2O2, 8-isoprostane, malondialdehyde, and nitrogen oxides. These techniques also include the study of markers of the toxic burden in the lungs (heavy metals and mineral compounds) that are important in occupational health exposure assessment. CONCLUSIONS In occupational medicine, the study of both volatile and nonvolatile respiratory biomarkers can be useful in medical surveillance of exposed workers, the early identification of respiratory diseases, or the monitoring of their development.
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Chinellato I, Piazza M, Peroni D, Sandri M, Chiorazzo F, Boner AL, Piacentini G. Bronchial and alveolar nitric oxide in exercise-induced bronchoconstriction in asthmatic children. Clin Exp Allergy 2012; 42:1190-6. [PMID: 22805466 DOI: 10.1111/j.1365-2222.2012.03973.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Epidemiological studies have shown an association between the severity of exercise-induced bronchoconstriction (EIB) and fractional exhaled nitric oxide at the flow of 50 mL/s (FeNO(50)). However, no study has assessed the correlation between alveolar production (C(alv)) and bronchial flux (J(NO)) of nitric oxide (NO) and EIB in asthmatic children. OBJECTIVE To identify the relationship between severity of EIB and bronchial or alveolar nitric oxide. METHODS Our group included 36 allergic children with intermittent asthma. The EIB was determined by a standard exercise challenge and the severity was expressed as the maximum change in percentage from the baseline value of lung function (ΔFEV(1)%, ΔFEF(25-75)%) after exercising. A chemiluminescence analyser at multiple flows was used to calculate FeNO(50), J(NO) and C(alv,) which reflect large airways, J(NO) and alveolar concentration of NO respectively. RESULTS Sixteen (44.4%) children presented a ∆FEV(1) ≥ 10%, eight (22.2%) had ∆FEV(1) ≥ 15% and nine (25%) children had a ∆FEF(25-75) ≥ 26%. A significant correlation was observed between severity of EIB and FeNO(50) , J(NO) and C(alv.) EIB was significantly more severe in children sensitive to indoor allergens compared with outdoor allergens only (P = 0.014); those children showed also higher levels of C(alv) (P = 0.003) and of J(NO) (P = 0.044). CONCLUSIONS AND CLINICAL RELEVANCE Our results suggest that inflammation is present in the central and peripheral airways and that it is associated with the severity of EIB. Clinicaltrials.gov NCT00952835.
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Affiliation(s)
- I Chinellato
- Department of Pediatrics, University of Verona, Verona, Italy
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37
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Axial distribution of nitric oxide airway production in asthma patients. Respir Physiol Neurobiol 2012; 185:313-8. [PMID: 23059373 DOI: 10.1016/j.resp.2012.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 09/21/2012] [Accepted: 09/21/2012] [Indexed: 11/23/2022]
Abstract
In healthy subjects, axial distribution of nitric oxide (NO) airway production is likely heterogeneous: notably a distal peak of production in terminal bronchioles and a quasi-nil NO production in the most of the conducting airways. In asthma, few information exists about the contributions of the proximal and distal airways to NO overproduction. In 18 asthma patients, sites of constriction after methacholine and adenosine 5'-monophosphate (AMP) challenges were assessed by ventilation distribution tests with He and SF(6). The resulting decreases in fractional exhaled NO (FENO) were measured. Changes in He and SF(6) slopes indicated a pre-acinar bronchoconstriction due to AMP and a more proximal action for methacholine. FENO decreased by 38.7% and 20.2% (p<0.001) after AMP and methacholine challenges, respectively. Significant FENO decreases after AMP and methacholine implies substantial pre-acinar but also, contrary to healthy subjects, more proximal airway production. In conclusion, nitric oxide overproduction in asthma patients appears to involve the most part of the conducting airways.
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Grob NM, Dweik RA. Exhaled nitric oxide in asthma: progress since the introduction of standardized methodology. J Breath Res 2012; 2:37002. [PMID: 20664809 DOI: 10.1088/1752-7155/2/3/037002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The measurement of nitric oxide (NO) in exhaled breath has given us the ability to learn about and monitor the inflammatory status of the airway through a non-invasive method that is easy to perform and repeat. This has been most useful in the diagnosis and management of asthma and has promised a seemingly unlimited potential for evaluating the airways and how clinical decisions are made (Grob N M and Dweik R A 2008 Chest133 837-9). The exhaled NO field was initially limited, however, due to the absence of standardized methodology. The ATS and ERS jointly released recommendations for standardized methods of measuring and reporting exhaled NO in 1999 that were revised in 2005 (1999 Am. J. Respir. Crit. Care. Med. 160 2104-17; 2005 Am. J. Respir. Crit. Care. Med. 171 912-30). In this paper, we summarize the literature that followed this standardization. We searched the literature for all papers that included the term 'exhaled nitric oxide' and selected those that followed ATS guidelines for online measurement for further review. We also reviewed cut-off values suggested by groups studying exhaled nitric oxide. We found a wide range of NO values reported for normal and asthma populations. The geometric mean for FE(NO) ranged from 10 ppb to 33 ppb in healthy adult control populations. For asthma, the FE(NO) geometric mean ranged from 6 ppb to 98 ppb. This considerable variation likely reflects the different clinical settings and purposes of measurement. Exhaled NO has been used for a multitude of reasons that range from screening, to diagnosis, to monitoring the effect of therapy. The field of exhaled NO has made undeniable progress since the standardization of the measurement methods. Our challenge now is to have guidelines to interpret exhaled NO levels in the appropriate context. As the utility of exhaled NO continues to evolve, it can serve as a good example of the crucial role of the standardization of collection and measurement methods to propel any new test in the right direction as it makes its way from a research tool to a clinically useful test.
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Affiliation(s)
- Natalia M Grob
- Department of Pulmonary, Allergy and Critical Care Medicine/Respiratory Institute, Cleveland Clinic, Cleveland, OH, USA
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Heijkenskjöld-Rentzhog C, Alving K, Kalm-Stephens P, Lundberg JO, Nordvall L, Malinovschi A. The fraction of NO in exhaled air and estimates of alveolar NO in adolescents with asthma: methodological aspects. Pediatr Pulmonol 2012; 47:941-9. [PMID: 22467536 DOI: 10.1002/ppul.22556] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 12/13/2011] [Accepted: 12/17/2011] [Indexed: 11/12/2022]
Abstract
RATIONALE This study investigated the oral contribution to exhaled NO in young people with asthma and its potential effects on estimated alveolar NO (Calv(NO) ), a proposed marker of inflammation in peripheral airways. Secondary aims were to investigate the effects of various exhalation flow-rates and the feasibility of different proposed adjustments of (Calv(NO) ) for trumpet model and axial diffusion (TMAD). METHODS Exhaled NO at flow rates of 50-300 ml/sec, and salivary nitrite was measured before and after antibacterial mouthwash in 29 healthy young people (10-20 years) and 29 with asthma (10-19 years). Calv(NO) was calculated using the slope-intercept model with and without TMAD adjustment. RESULTS Exhaled NO at 50 ml/sec decreased significantly after mouthwash, to a similar degree in asthmatic and healthy subjects (8.8% vs. 9.8%, P = 0.49). The two groups had similar salivary nitrite levels (56.4 vs. 78.4 µM, P = 0.25). Calv(NO) was not significantly decreased by mouthwash. Calv(NO) levels were similar when flow-rates between 50-200 or 100-300 ml/sec were used (P = 0.34 in asthmatics and P = 0.90 in healthy subjects). A positive association was found between bronchial and alveolar NO in asthmatic subjects and this disappeared after the TMAD-adjustment. Negative TMAD-adjusted Calv(NO) values were found in a minority of the subjects. CONCLUSIONS Young people with and without asthma have similar salivary nitrite levels and oral contributions to exhaled NO and therefore no antibacterial mouthwash is necessary in routine use. TMAD corrections of alveolar NO could be successfully applied in young people with asthma and yielded negative results only in a minority of subjects.
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Ludviksdottir D, Diamant Z, Alving K, Bjermer L, Malinovschi A. Clinical aspects of using exhaled NO in asthma diagnosis and management. CLINICAL RESPIRATORY JOURNAL 2012; 6:193-207. [DOI: 10.1111/crj.12001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
| | | | - Kjell Alving
- Department of Women's and Children's Health; Uppsala University; Uppsala; Sweden
| | - Leif Bjermer
- Department of Respiratory Diseases and Allergology; Skane University; Lund; Sweden
| | - Andrei Malinovschi
- Department of Medical Sciences: Clinical Physiology; Uppsala University; Uppsala; Sweden
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Munakata M. Exhaled nitric oxide (FeNO) as a non-invasive marker of airway inflammation. Allergol Int 2012; 61:365-72. [PMID: 22824979 DOI: 10.2332/allergolint.12-rai-0461] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Indexed: 11/20/2022] Open
Abstract
Nitric oxide (NO), previously very famous for being an environmental pollutant in the field of pulmonary medicine, is now known as the smallest, lightest, and most famed molecule to act as a biological messenger. Furthermore, recent basic researches have revealed the production mechanisms and physiological functions of nitric oxide in the lung, and clinical researches have been clarifying its tight relation to airway inflammation in asthma. On the bases of this knowledge, fractional nitric oxide (FeNO) has now been introduced as one of the most practical tools for the diagnosis and management of bronchial asthma.
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In moderate-to-severe asthma patients monitoring exhaled nitric oxide during exacerbation is not a good predictor of spirometric response to oral corticosteroid. J Allergy Clin Immunol 2012; 129:1491-8. [PMID: 22560478 DOI: 10.1016/j.jaci.2012.03.036] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 03/20/2012] [Accepted: 03/23/2012] [Indexed: 11/22/2022]
Abstract
BACKGROUND The importance of monitoring exhaled nitric oxide (NO) in asthma remains controversial. OBJECTIVE To measure exhaled NO, postnebulized albuterol/ipratropium spirometry, and Asthma Control Test (ACT) during asthma exacerbation requiring 8- to 10-day tapering oral corticosteroid in nonsmoking patients with moderate-to-severe asthma on moderate-dose inhaled corticosteroid and long-acting β(2)-agonist but not maintenance oral corticosteroid. METHODS After measuring the fraction of exhaled NO (Feno [ppb]) at 50, 100, 150, and 200 mL/s, the total Feno at 50 mL/s (ppb), large central airway NO flux (J'(awNO) [nL/s]), and peripheral small airway/alveolar NO concentration (C(ANO) [ppb]) were calculated and corrected for NO axial back-diffusion. Outpatient exacerbation required the patient with asthma to be afebrile with normal chest x-ray and white blood cell count. RESULTS Group 1 included 17 patients (6 men) with asthma, age 52 ± 12 years, studied at baseline, during 18 exacerbations with abnormal Feno at 50 mL/s, J'(awNO), and/or C(ANO), and post 8- to 10-day tapering 40 mg prednisone (recovery). Baseline: IgE, 332 ± 243 Kμ; total blood eosinophils, 304 ± 266 cells/μL; body mass index, 28 ± 6; ACT, 16 to 19; and FEV(1), 2.5 ± 0.7 L (86% ± 20% predicted); exacerbation: FEV(1), 1.7 ± 0.4 L (60% ± 17%) (P < .001); recovery: FEV(1), 2.5 ± 0.7 L (85% ± 13%) (P < .001). Group 2 included 11 (7 men) similarly treated patients with asthma, age 49 ± 14 years, studied at baseline, during 15 exacerbations with normal Feno at 50 mL/s, J'(awNO), and C(ANO). Baseline: IgE, 307 ± 133 Kμ; total blood eosinophils, 296 ± 149 cells/μL; body mass index, 28 ± 6; ACT, 16 to 19; and FEV(1), 2.7 ± 0.9 L (71% ± 12% predicted); exacerbation: FEV(1), 1.7 ± 0.6 L (54% ± 19%) (P< .006); recovery: FEV(1), 2.7 ± 0.9 L (70% ± 14%) (P= .002). On comparing group 1 versus group 2, there was no significant difference for baseline IgE, eosinophils, body mass index, and ACT and similar significant (≤.006) decrease from baseline in FEV(1) (L) during exacerbation and similar increase (≤.006) at recovery. CONCLUSIONS Increased versus normal exhaled NO during outpatient exacerbation in patients with moderate-to-severe asthma on inhaled corticosteroid and long-acting β(2)-agonist but not maintenance oral corticosteroid does not preclude a robust clinical and spirometric response to tapering oral prednisone.
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Short PM, Williamson PA, Lipworth BJ. Effects of extra-fine inhaled and oral corticosteroids on alveolar nitric oxide in COPD. Lung 2012; 190:395-401. [PMID: 22350679 DOI: 10.1007/s00408-012-9378-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 01/22/2012] [Indexed: 11/27/2022]
Abstract
PURPOSE Alveolar nitric oxide (CA(NO)) has been suggested as a surrogate marker of distal airway inflammation in COPD. Coarse particle-inhaled corticosteroids (ICS) have been shown not to suppress CA(NO). We evaluated whether extra-fine particle size ICS (HFA-BDP) or systemic oral corticosteroids could suppress CA(NO) in COPD. METHODS Chronic obstructive pulmonary disease (COPD) patients with a FEV1/FVC ratio <0.7, FEV1 <80% predicted with CA(NO) > 2 ppb underwent a double-blind randomized, controlled, crossover trial with an open-label systemic steroid comparator. After a 2 week steroid washout period, participants were randomized to 3 weeks of 100 mcg of HFA-BDP twice daily and then 3 weeks of 400 mcg of HFA-BDP twice daily, or matched placebos with subsequent crossover. All patients then received 1 week open-label, 25 mg/day of prednisolone. Exhaled nitric oxide, plasma cortisol, and lung function were recorded. CA(NO) was corrected for axial diffusion. RESULTS In 16 participants, there were no significant differences seen with either dose of HFA-BDP compared with placebo. Oral prednisolone significantly reduced FE(NO) and J'aw(NO) but not CA(NO). Plasma cortisol was significantly suppressed by oral prednisolone only. CONCLUSIONS Whilst CA(NO) remains a biomarker of interest in COPD, it is not suppressed by systemic or extra-fine particle ICS. CA(NO) is not a useful marker for monitoring response of small airway disease to therapies in COPD. The study was approved by the local Committee on Medical Research Ethics and registered on ClinicalTrials.Gov (NCT 00921921).
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Affiliation(s)
- Philip M Short
- Asthma and Allergy Research Group, Centre for Cardiovascular and Lung Biology, Division of Medical Sciences, University of Dundee, Dundee DD1 9SY, Scotland
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Kobayashi D, Tochino Y, Kanazawa H, Ichimaru Y, Kyoh S, Asai K, Hirata K. Comparison of alveolar nitric oxide concentrations using two different methods for assessing small airways obstruction in asthma. Respirology 2011; 16:862-8. [PMID: 21564400 DOI: 10.1111/j.1440-1843.2011.01989.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Fractional exhaled nitric oxide (F(E) NO) is considered a potentially useful biomarker for airway inflammation. A two-compartment model (2CM) of pulmonary NO dynamics has been used for the evaluation of bronchial NO flux (J'awNO) and alveolar NO concentration (C(A) NO) in asthmatic patients. Recently, the trumpet shape of the airway tree and axial diffusion (TMAD) model has been reported as a modification of the 2CM. This study was designed to determine the validity of C(A) NO measurement using the TMAD model for assessing small airways inflammation in asthma. METHODS A total of 52 asthmatic patients and 12 normal control subjects were included in the study. Methacholine inhalation challenge and pulmonary function tests, sputum induction, and exhaled NO measurements at several flow rates were performed. J'awNO and C(A) NO were calculated using both the 2CM (C(A) NO( 2CM) , J'awNO( 2CM) ) and TMAD models (C(A) NO( TMAD) , J'awNO( TMAD) ). RESULTS Both J'awNO (J'awNO( 2CM) and J'awNO( TMAD) ) and C(A) NO (C(A) NO( 2CM) and C(A) NO( TMAD) ) were significantly higher in asthmatic patients than in control subjects. C(A) NO( 2CM) was significantly correlated with FEV(1) /FVC (r = -0.35, P = 0.01), FEF(25-75) (r = -0.45, P < 0.001) and sputum eosinophils (r = 0.32, P = 0.02). In contrast, C(A) NO( TMAD) was significantly correlated with FEF(25-75) (r = -0.42, P = 0.002) but not with FEV(1) /FVC or sputum eosinophils. CONCLUSIONS C(A) NO( TMAD) is more specific as an indicator of small airways obstruction than C(A) NO( 2CM) . Assessment of small airways obstruction using the TMAD model may clarify the role of the small airways in the pathogenesis of asthma.
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Affiliation(s)
- Daiki Kobayashi
- Department of Respiratory Medicine, Graduate School of Medicine, Osaka City University, Osaka, Japan.
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Hemmingsson TE, Linnarsson D, Frostell C, Van Muylem A, Kerckx Y, Gustafsson LE. Effects of ambient pressure on pulmonary nitric oxide. J Appl Physiol (1985) 2011; 112:580-6. [PMID: 22162525 DOI: 10.1152/japplphysiol.01183.2011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Airway nitric oxide (NO) has been proposed to play a role in the development of high-altitude pulmonary edema. We undertook a study of the effects of acute changes of ambient pressure on exhaled and alveolar NO in the range 0.5-4 atmospheres absolute (ATA, 379-3,040 mmHg) in eight healthy subjects breathing normoxic nitrogen-oxygen mixtures. On the basis of previous work with inhalation of low-density helium-oxygen gas, we expected facilitated backdiffusion and lowered exhaled NO at 0.5 ATA and the opposite at 4 ATA. Instead, the exhaled NO partial pressure (Pe(NO)) did not differ between pressures and averaged 1.21 ± 0.16 (SE) mPa across pressures. As a consequence, exhaled NO fractions varied inversely with pressure. Alveolar estimates of the NO partial pressure differed between pressures and averaged 88 (P = 0.04) and 176 (P = 0.009) percent of control (1 ATA) at 0.5 and 4 ATA, respectively. The airway contribution to exhaled NO was reduced to 79% of control (P = 0.009) at 4 ATA. Our finding of the same Pe(NO) at 0.5 and 1 ATA is at variance with previous findings of a reduced Pe(NO) with inhalation of low-density gas at normal pressure, and this discrepancy may be due to the much longer durations of low-density gas breathing in the present study compared with previous studies with helium-oxygen breathing. The present data are compatible with the notion of an enhanced convective backtransport of NO, compensating for attenuated backdiffusion of NO with increasing pressure. An alternative interpretation is a pressure-induced suppression of NO formation in the airways.
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Affiliation(s)
- Tryggve E Hemmingsson
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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Kiyokawa H, Matsumoto H, Nakaji H, Niimi A, Ito I, Ono K, Takeda T, Oguma T, Otsuka K, Mishima M. Centrilobular opacities in the asthmatic lung successfully treated with inhaled ciclesonide and tiotropium: with assessment of alveolar nitric oxide levels. Allergol Int 2011; 60:381-5. [PMID: 21364311 DOI: 10.2332/allergolint.10-cr-0251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 10/03/2010] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Despite the fact that bronchioles are involved in asthma, there have been limited asthmatic cases showing marked centrilobular opacities on computed tomography (CT) chest scans. Systemic corticosteroids have been administered in such cases, but the efficacy of extra-fine particle inhaled corticosteroids has not been assessed. CASE SUMMARY A previously healthy 64-year-old man presented with a four-month history of productive cough and progressive dyspnea despite a combination therapy with inhaled salmeterol (50 μg bid) and fluticasone (500 μg bid), sustained-release theophylline, and pranlukast because of suspicion of asthma. Physical examination revealed wheezing at the end of forced expiration. High resolution CT chest scan showed diffuse centrilobular opacities, bronchiectatic changes, and bronchial wall thickening. Transbronchial lung biopsy, bronchoalveolar lavage fluid, and transbronchial biopsy all showed predominant eosinophil infiltrates, suggesting that eosinophilic inflammation across the entire airway tree caused the abnormal CT findings. Alveolar fraction of exhaled nitric oxide level, a non-invasive marker of eosinophilic peripheral airway inflammation, was also elevated. Because he refused systemic corticosteroids, inhaled ciclesonide (400 μg bid) and inhaled tiotropium were added on to his current medication under careful observation. His symptoms, pulmonary function and CT findings promptly improved, and he had fully recovered at follow-up. DISCUSSION Extra-fine particle inhaled corticosteroids could be an alternative approach in centrilobular opacities caused by eosinophilic peripheral airway inflammation.
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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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Shorter JH, Nelson DD, McManus JB, Zahniser MS, Sama SR, Milton DK. Clinical study of multiple breath biomarkers of asthma and COPD (NO, CO(2), CO and N(2)O) by infrared laser spectroscopy. J Breath Res 2011; 5:037108. [PMID: 21757803 DOI: 10.1088/1752-7155/5/3/037108] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Breath analysis is a powerful non-invasive technique for the diagnosis and monitoring of respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD). Exhaled nitric oxide (NO) and carbon monoxide (CO) are markers of airway inflammation and can indicate the extent of respiratory diseases. We have developed a compact fast response quantum cascade laser system for analysis of multiple gases by tunable infrared absorption spectroscopy. The ARI breath analysis instrument has been deployed in a study of exhaled breath from patients with asthma or COPD. A total of 173 subjects participated, including both adult and pediatric patients. Patients in asthma or COPD exacerbations were evaluated twice-during the exacerbation and at a follow-up visit-to compare variations in breath biomarkers during these events. The change in exhaled NO levels between exacerbation and 'well' visits is consistent with spirometry data collected. Respiratory models are important for understanding the exchange dynamics of nitric oxide and other species in the lungs and airways. At each patient's visit, tests were conducted at four expiratory flow rates. We have applied a trumpet model with axial diffusion to the multi-flow exhaled nitric oxide data, obtaining NO alveolar concentrations and airway fluxes. We found higher airway fluxes for those with more severe asthma and during exacerbation events. The alveolar concentrations from the model were higher in adults with asthma and COPD, but this trend was less clear among the pediatric subjects.
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Affiliation(s)
- Joanne H Shorter
- Center for Atmospheric and Environmental Chemistry, Aerodyne Research, Inc., Billerica, MA, USA.
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Rolla G, Malinovschi A, Badiu I, Heffler E, Petrarulo M, Bucca C, Brussino L. The increase in exhaled NO following allergen challenge is not associated with airway acidification. Eur J Clin Invest 2011; 41:411-6. [PMID: 21114492 DOI: 10.1111/j.1365-2362.2010.02423.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Exhaled nitric oxide (NO), commonly accepted marker of airways inflammation, may be generated both by specific enzymes, NO synthases, as well as by nonenzymatic reduction in its metabolites. During asthma exacerbations, owing to lower airways pH, it has been reported that nitrite reduction may contribute to the increase in exhaled NO. Allergen exposure, an important cause of asthma exacerbations, is also known to increase exhaled NO. DESIGN To investigate whether cat allergen exposure of cat-sensitized asthmatics leads to airway acidification, which could explain the expected increase in exhaled NO. Twelve nonsmoking, cat-sensitized patients (nine women) aged 33·5 (22-54) years with mild intermittent asthma performed a cat allergen challenge. Exhaled NO at 50-200 mL s(-1), nasal NO, exhaled breath condensate (EBC) pH, nitrite and nitrate were measured before, 8 and 24 h after allergen challenge. RESULTS A significant increase in FE(NO 50) was observed 24 h after allergen challenge compared to baseline: 110 ppb (34, 143) vs. 60 ppb (19, 122), P = 0·006. This was mainly explained by an increase in bronchial NO flux (P = 0·02), while no changes in EBC pH were observed (P = 0·35). CONCLUSIONS Allergen exposure is not associated with airways acidification, implying that the observed increase in exhaled NO is probably because of enzymatic NO production.
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Affiliation(s)
- Giovanni Rolla
- Allergy and Clinical Immunology, University of Torino, AO Mauriziano Umberto I, Torino, Italy.
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Malinovschi A, Pizzimenti S, Sciascia S, Heffler E, Badiu I, Rolla G. Exhaled breath condensate nitrates, but not nitrites or FENO, relate to asthma control. Respir Med 2011; 105:1007-13. [PMID: 21277184 DOI: 10.1016/j.rmed.2010.12.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 12/15/2010] [Accepted: 12/19/2010] [Indexed: 10/18/2022]
Abstract
BACKGROUND Asthma is a chronic respiratory disease, characterised by airways inflammation, obstruction and hyperresponsiveness. Asthma control is the goal of asthma treatment, but many patients have sub-optimal control. Exhaled NO and exhaled breath condensate (EBC) NO metabolites (nitrites and nitrates) measurements are non-invasive tools to assess airways inflammation. Our aim was to investigate the relationships between asthma control and the above-named biomarkers of airways inflammation. METHODS Thirty-nine non-smoking asthmatic patients (19 women) aged 50 (21-80) years performed measurements of exhaled NO (FENO), EBC nitrates, nitrites and pH, and answered Asthma Control Questionnaire (ACQ) and Asthma Control Test (ACT)-questionnaire. RESULTS The ACT and ACQ score were strongly interrelated (ρ = -0.84, p < 0.001). No relationships between ACT or ACQ score and FENO were found (p > 0.05). EBC nitrates were negatively related to ACT score (ρ = -0.34, p = 0.03) and positively related to ACQ score (ρ = 0.41, p = 0.001) while no relation of EBC nitrites to either ACQ or ACT score was found (p>0.05). CONCLUSION EBC nitrates were the only biomarker that was significantly related to asthma control. This suggests that nitrates, but not nitrites or FENO, reflect an aspect of airways inflammation that is closer related to asthma symptoms. Therefore there is a potential role for EBC nitrates in objective assessment of asthma control.
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Affiliation(s)
- Andrei Malinovschi
- Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala, Sweden.
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