1
|
Meys R, Schiefer M, de Nijs SB, Bindels H, de Kruif MD. Measurement of Dynamic Hyperinflation During the 6-Minute Walk Test Using a Mobile Device. Respir Care 2018; 64:182-188. [PMID: 30584067 DOI: 10.4187/respcare.06307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Dynamic hyperinflation is a major cause of dyspnea in patients with COPD. Dynamic hyperinflation is usually measured with cardiopulmonary exercise testing, but this test requires maximal effort from the patient, and inspiratory capacity (IC) measurements may influence test results. This study investigated another approach by measuring dynamic hyperinflation during the more natural and better-tolerated 6-min walk test (6MWT), using a mobile system for IC measurements. METHODS Twenty subjects were studied, including 10 healthy subjects and 10 subjects with COPD. Each subject performed a pair of 6MWTs. RESULTS The study showed that test-retest reliability in healthy subjects was excellent (intraclass correlation coefficient 0.995). In addition, mean resting IC in healthy subjects (3.27 ± 0.77 L) was not affected at the end of the 6MWT, whereas mean resting IC in subjects with COPD (2.45 ± 0.90 L) decreased to 1.93 L ± 0.68 L at the end of the 6MWT (P = .004). The tolerability of the device for subjects with COPD appeared to be only slightly hampered by an increased sense of dyspnea attributed to wearing a mask. CONCLUSIONS This study provides a proof of principle for mobile IC measurements during the 6MWT, demonstrating good test performance, reasonable tolerability, and a power to differentiate normal from pathologic conditions.
Collapse
Affiliation(s)
- Roy Meys
- Department of Pulmonary Medicine, Zuyderland Medical Center, Heerlen, The Netherlands
| | - Mart Schiefer
- Department of Pulmonary Medicine, Zuyderland Medical Center, Heerlen, The Netherlands
| | - Selma B de Nijs
- Department of Pulmonary Medicine, University Medical Center Utrecht, Heidelberglaan, Utrecht, The Netherlands
| | - Henk Bindels
- Department of Pulmonary Medicine, Zuyderland Medical Center, Heerlen, The Netherlands
| | - Martijn D de Kruif
- Department of Pulmonary Medicine, Zuyderland Medical Center, Heerlen, The Netherlands.
| |
Collapse
|
2
|
Coumou H, Westerhof GA, de Nijs SB, Zwinderman AH, Bel EH. Predictors of accelerated decline in lung function in adult-onset asthma. Eur Respir J 2018; 51:51/2/1701785. [PMID: 29444915 DOI: 10.1183/13993003.01785-2017] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/23/2017] [Indexed: 12/26/2022]
Abstract
Little is known about the prognosis of adults with new-onset asthma. Cross-sectional studies suggest that these patients may exhibit accelerated decline in forced expiratory volume in 1 s (FEV1). However, risk factors for accelerated decline in lung function have not yet been identified.We aimed to identify these risk factors in a prospective 5-year follow-up study in 200 adults with newly diagnosed asthma. In the current study, clinical, functional and inflammatory parameters were assessed annually for 5 years. Linear mixed-effects models were used to identify predictors.Evaluable lung function sets of 141 patients were available. Median (interquartile range) change in post-bronchodilator FEV1 was -17.5 (-54.2 to +22.4) mL per year. Accelerated decline in FEV1 was defined by the lower quartile of decline (>54.2 mL per year). Nasal polyps, number of blood and sputum eosinophils, body mass index, and level of exhaled nitric oxide were univariably associated with decline in lung function. Only the latter two were independently associated. Using cut-off values to identify patients at highest risk showed accelerated decline in FEV1 in all patients with combined exhaled nitric oxide fraction (FeNO) ≥57 ppb and body mass index (BMI) ≤23 kg·m-2We conclude that adults with new-onset asthma with both high levels of exhaled nitric oxide and low BMI are at risk of accelerated decline in lung function.
Collapse
Affiliation(s)
- Hanneke Coumou
- Dept of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Guus A Westerhof
- Dept of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Selma B de Nijs
- Dept of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Aeilko H Zwinderman
- Dept of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Elisabeth H Bel
- Dept of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
3
|
Westerhof GA, Coumou H, de Nijs SB, Weersink EJ, Bel EH. Clinical predictors of remission and persistence of adult-onset asthma. J Allergy Clin Immunol 2017; 141:104-109.e3. [PMID: 28438546 DOI: 10.1016/j.jaci.2017.03.034] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 03/10/2017] [Accepted: 03/29/2017] [Indexed: 01/29/2023]
Abstract
BACKGROUND Adult-onset asthma is an important but relatively understudied asthma phenotype and little is known about its natural course and prognosis. The remission rate is believed to be low, and it is still obscure which factors predict remission or persistence of the disease. OBJECTIVE This study sought to determine the remission rate and identify predictors of persistence and remission of adult-onset asthma. METHODS Two hundred adult patients with recently diagnosed (<1 year) asthma were recruited from secondary and tertiary pulmonary clinics and prospectively followed for 5 years. Clinical, functional, and inflammatory parameters were assessed at baseline and at yearly visits. Asthma remission was defined as absence of asthma symptoms for ≥1 year and no asthma medication use for ≥1 year. Descriptive statistics and logistic regression analysis were performed. RESULTS Five-year follow-up data of 170 patients (85%) was available. Of these, 27 patients (15.9%) experienced asthma remission. Patients with asthma persistence were older, had worse asthma control, required higher doses of inhaled corticosteroids, had more severe airway hyperresponsiveness, more often nasal polyps, and higher levels of blood neutrophils as compared to patients who experienced clinical remission. In a multivariable logistic regression analysis, only moderate to severe bronchial hyperresponsiveness and nasal polyps were independent predictors of asthma persistence. Patients with these 2 characteristics had <1% chance of asthma remission. CONCLUSIONS One in 6 patients with adult-onset asthma experiences remission within the first 5 years of the disease. In patients with moderate to severe bronchial hyperresponsiveness and nasal polyposis, the chance of remission is close to zero.
Collapse
Affiliation(s)
- Guus A Westerhof
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
| | - Hanneke Coumou
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Selma B de Nijs
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Els J Weersink
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Elizabeth H Bel
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
4
|
de Groot JC, Storm H, Amelink M, de Nijs SB, Eichhorn E, Reitsma BH, Bel EH, ten Brinke A. Clinical profile of patients with adult-onset eosinophilic asthma. ERJ Open Res 2016; 2:00100-2015. [PMID: 27730197 PMCID: PMC5005181 DOI: 10.1183/23120541.00100-2015] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/08/2016] [Indexed: 01/19/2023] Open
Abstract
Adult-onset eosinophilic asthma is increasingly recognised as a severe and difficult-to-treat subtype of asthma. In clinical practice, early recognition of patients with this asthma subtype is important because it may have treatment implications. Therefore, physicians need to know the distinct characteristics of this asthma phenotype. The objective of the present study was to determine the characteristic profile of patients with adult-onset eosinophilic asthma. 130 patients with adult-onset (>18 years of age) asthma and high blood eosinophil counts (≥0.3×109 L-1) were compared with 361 adult-onset asthma patients with low (<0.3×109 L-1) blood eosinophils. Measurements included a series of clinical, functional and imaging parameters. Patients with high blood eosinophils were more often male, had less well controlled asthma and higher exacerbation rates, despite the use of higher doses of inhaled corticosteroids. They had higher levels of total IgE without more sensitisation to common inhaled allergens. In addition, these patients had worse lung function, and more often showed fixed airflow limitation, air trapping, nasal polyposis and abnormalities on sinus computed tomography scanning. Chronic rhinosinusitis, air trapping and male sex were three independent factors associated with blood eosinophilia (adjusted OR 3.8 (95% CI 1.7-8.1), 3.0 (95% CI 1.1-8.1) and 2.4 (95% CI 1.3-4.4), respectively). Patients with adult-onset asthma with elevated blood eosinophils exhibit a distinct profile, which can readily be recognised in clinical practice.
Collapse
Affiliation(s)
- Jantina C. de Groot
- Dept of Respiratory Medicine, Medical Centre Leeuwarden, Leeuwarden, The Netherlands
| | - Huib Storm
- Dept of Clinical Chemistry, Medical Centre Leeuwarden, Leeuwarden, The Netherlands
| | - Marijke Amelink
- Dept of Respiratory Medicine, Amsterdam Medical Centre, Amsterdam, The Netherlands
| | - Selma B. de Nijs
- Dept of Respiratory Medicine, Amsterdam Medical Centre, Amsterdam, The Netherlands
| | - Edwin Eichhorn
- Dept of Ear, Nose and Throat Medicine, Medical Centre Leeuwarden, Leeuwarden, The Netherlands
| | - Bennie H. Reitsma
- Dept of Respiratory Medicine, Medical Centre Leeuwarden, Leeuwarden, The Netherlands
| | - Elisabeth H.D. Bel
- Dept of Respiratory Medicine, Amsterdam Medical Centre, Amsterdam, The Netherlands
| | - Anneke ten Brinke
- Dept of Respiratory Medicine, Medical Centre Leeuwarden, Leeuwarden, The Netherlands
| |
Collapse
|
5
|
de Groot JC, Amelink M, de Nijs SB, Plaat R, Reitsma BH, Storm H, Bel EHD, Ten Brinke A. Risk factors for frequent severe exacerbations in late-onset eosinophilic asthma. Am J Respir Crit Care Med 2016; 192:899-902. [PMID: 26426787 DOI: 10.1164/rccm.201505-1003le] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
| | | | | | - Robin Plaat
- 1 Medical Centre Leeuwarden Leeuwarden, the Netherlands
| | | | - Huib Storm
- 1 Medical Centre Leeuwarden Leeuwarden, the Netherlands
| | | | | |
Collapse
|
6
|
Westerhof GA, Korevaar DA, Amelink M, de Nijs SB, de Groot JC, Wang J, Weersink EJ, ten Brinke A, Bossuyt PM, Bel EH. Biomarkers to identify sputum eosinophilia in different adult asthma phenotypes. Eur Respir J 2015; 46:688-96. [PMID: 26113672 DOI: 10.1183/09031936.00012415] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 04/15/2015] [Indexed: 01/22/2023]
Abstract
Several biomarkers have been used to assess sputum eosinophilia in asthma. It has been suggested that the diagnostic accuracy of these biomarkers might differ between asthma phenotypes. We investigated the accuracy of biomarkers in detecting sputum eosinophilia (≥3%) in different adult asthma phenotypes.Levels of eosinophils in blood and sputum, exhaled nitric oxide fraction (FeNO) and total immunoglobulin (Ig)E from 336 adult patients, enrolled in three prospective observational clinical trials and recruited at five pulmonology outpatient departments, were analysed. Areas under the receiver operating characteristics curves (AUC) for detecting sputum eosinophilia were calculated and compared between severe and mild, obese and nonobese, atopic and nonatopic and (ex-)smoking and never-smoking asthma patients.Sputum eosinophilia was present in 116 patients (35%). In the total group the AUC was 0.83 (95% CI 0.78-0.87) for blood eosinophils, 0.82 (0.77-0.87) for FeNO and 0.69 (0.63-0.75) for total IgE. AUCs were similar for blood eosinophils and FeNO between different phenotypes. Total IgE was less accurate in detecting sputum eosinophilia in atopic and obese patients than in nonatopic and nonobese patients.Blood eosinophils and FeNO had comparable diagnostic accuracy (superior to total IgE) in identifying sputum eosinophilia in adult asthma patients, irrespective of asthma phenotype such as severe, nonatopic, obese and smoking-related asthma.
Collapse
Affiliation(s)
- Guus A Westerhof
- Department of Respiratory Medicine, Academic Medical Centre, Amsterdam, the Netherlands
| | - Daniël A Korevaar
- Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, Amsterdam, the Netherlands
| | - Marijke Amelink
- Department of Respiratory Medicine, Academic Medical Centre, Amsterdam, the Netherlands
| | - Selma B de Nijs
- Department of Respiratory Medicine, Academic Medical Centre, Amsterdam, the Netherlands
| | - Jantina C de Groot
- Department of Respiratory Medicine, Medical Centre Leeuwarden, Leeuwarden, the Netherlands
| | - Junfeng Wang
- Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, Amsterdam, the Netherlands
| | - Els J Weersink
- Department of Respiratory Medicine, Academic Medical Centre, Amsterdam, the Netherlands
| | - Anneke ten Brinke
- Department of Respiratory Medicine, Medical Centre Leeuwarden, Leeuwarden, the Netherlands
| | - Patrick M Bossuyt
- Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, Amsterdam, the Netherlands
| | - Elisabeth H Bel
- Department of Respiratory Medicine, Academic Medical Centre, Amsterdam, the Netherlands
| |
Collapse
|
7
|
Abstract
Asthma that starts in adulthood differs from childhood-onset asthma in that it is often non-atopic, more severe and associated with a faster decline in lung function. Understanding of the underlying mechanism of adult-onset asthma and identification of specific phenotypes may further our understanding of pathophysiology and treatment response, leading to better targeting of both existing and new approaches for personalised management. Pivotal studies in past years have led to sustained progress in many areas, ranging from risk factors for development, identification of different phenotypes, and introduction of new therapies. This review highlights and discusses literature on adult-onset asthma, with special focus on the differences from childhood-onset asthma, risk factors for development, phenotypes of adult-onset asthma and new approaches for personalised management.
Collapse
Affiliation(s)
- Selma B de Nijs
- Dept of Respiratory Medicine, Academic Medical Centre and University of Amsterdam, Amsterdam, The Netherlands.
| | | | | |
Collapse
|
8
|
Paulus F, Veelo DP, de Nijs SB, Beenen LFM, Bresser P, de Mol BAJM, Binnekade JM, Schultz MJ. Manual hyperinflation partly prevents reductions of functional residual capacity in cardiac surgical patients--a randomized controlled trial. Crit Care 2011; 15:R187. [PMID: 21819581 PMCID: PMC3387630 DOI: 10.1186/cc10340] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 06/21/2011] [Accepted: 08/05/2011] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Cardiac surgery is associated with post-operative reductions of functional residual capacity (FRC). Manual hyperinflation (MH) aims to prevent airway plugging, and as such could prevent the reduction of FRC after surgery. The main purpose of this study was to determine the effect of MH on post-operative FRC of cardiac surgical patients. METHODS This was a randomized controlled trial of patients after elective coronary artery bypass graft and/or valve surgery admitted to the intensive care unit (ICU) of a university hospital. Patients were randomly assigned to a "routine MH group" (MH was performed within 30 minutes after admission to the ICU and every 6 hours thereafter, and before tracheal extubation), or a "control group" (MH was performed only if perceptible (audible) sputum was present in the larger airways causing problems with mechanical ventilation, or if oxygen saturation (SpO2) dropped below 92%). The primary endpoint was the reduction of FRC from the day before cardiac surgery to one, three, and five days after tracheal extubation. Secondary endpoints were SpO2 (at similar time points) and chest radiograph abnormalities, including atelectasis (at three days after tracheal extubation). RESULTS A total of 100 patients were enrolled. Patients in the routine MH group showed a decrease of FRC on the first post-operative day to 71% of the pre-operative value, versus 57% in the control group (P = 0.002). Differences in FRC became less prominent over time; differences between the two study groups were no longer statistically significant at Day 5. There were no differences in SpO2 between the study groups. Chest radiographs showed more abnormalities (merely atelectasis) in the control group compared to patients in the routine MH group (P = 0.002). CONCLUSIONS MH partly prevents the reduction of FRC in the first post-operative days after cardiac surgery. TRIAL REGISTRATION Netherlands Trial Register (NTR): NTR1384. http://www.trialregister.nl.
Collapse
Affiliation(s)
- Frederique Paulus
- Department of Intensive Care Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
de Nijs SB, Fens N, Lutter R, Dijkers E, Krouwels FH, Smids-Dierdorp BS, van Steenwijk RP, Sterk PJ. Airway inflammation and mannitol challenge test in COPD. Respir Res 2011; 12:11. [PMID: 21241520 PMCID: PMC3036630 DOI: 10.1186/1465-9921-12-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 01/18/2011] [Indexed: 11/10/2022] Open
Abstract
Background Eosinophilic airway inflammation has successfully been used to tailor anti-inflammatory therapy in chronic obstructive pulmonary disease (COPD). Airway hyperresponsiveness (AHR) by indirect challenges is associated with airway inflammation. We hypothesized that AHR to inhaled mannitol captures eosinophilia in induced sputum in COPD. Methods Twenty-eight patients (age 58 ± 7.8 yr, packyears 40 ± 15.5, post-bronchodilator FEV1 77 ± 14.0%predicted, no inhaled steroids ≥4 wks) with mild-moderate COPD (GOLD I-II) completed two randomized visits with hypertonic saline-induced sputum and mannitol challenge (including sputum collection). AHR to mannitol was expressed as response-dose-ratio (RDR) and related to cell counts, ECP, MPO and IL-8 levels in sputum. Results There was a positive correlation between RDR to mannitol and eosinophil numbers (r = 0.47, p = 0.03) and level of IL-8 (r = 0.46, p = 0.04) in hypertonic saline-induced sputum. Furthermore, significant correlations were found between RDR and eosinophil numbers (r = 0.71, p = 0.001), level of ECP (r = 0.72, p = 0.001), IL-8 (r = 0.57, p = 0.015) and MPO (r = 0.64, p = 0.007) in sputum collected after mannitol challenge. ROC-curves showed 60% sensitivity and 100% specificity of RDR for >2.5% eosinophils in mannitol-induced sputum. Conclusions In mild-moderate COPD mannitol hyperresponsiveness is associated with biomarkers of airway inflammation. The high specificity of mannitol challenge suggests that the test is particularly suitable to exclude eosinophilic airways inflammation, which may facilitate individualized treatment in COPD. Trial registration Netherlands Trial Register (NTR): NTR1283
Collapse
Affiliation(s)
- Selma B de Nijs
- Department of Respiratory Medicine, Academic Medical Centre and University of Amsterdam, Amsterdam, The Netherlands.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Lazar Z, Fens N, van der Maten J, van der Schee MP, Wagener AH, de Nijs SB, Dijkers E, Sterk PJ. Electronic nose breathprints are independent of acute changes in airway caliber in asthma. Sensors (Basel) 2010; 10:9127-38. [PMID: 22163399 PMCID: PMC3230982 DOI: 10.3390/s101009127] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 09/15/2010] [Accepted: 09/25/2010] [Indexed: 11/16/2022]
Abstract
Molecular profiling of exhaled volatile organic compounds (VOC) by electronic nose technology provides breathprints that discriminate between patients with different inflammatory airway diseases, such as asthma and COPD. However, it is unknown whether this is determined by differences in airway caliber. We hypothesized that breathprints obtained by electronic nose are independent of acute changes in airway caliber in asthma. Ten patients with stable asthma underwent methacholine provocation (Visit 1) and sham challenge with isotonic saline (Visit 2). At Visit 1, exhaled air was repetitively collected pre-challenge, after reaching the provocative concentration (PC(20)) causing 20% fall in forced expiratory volume in 1 second (FEV(1)) and after subsequent salbutamol inhalation. At Visit 2, breath was collected pre-challenge, post-saline and post-salbutamol. At each occasion, an expiratory vital capacity was collected after 5 min of tidal breathing through an inspiratory VOC-filter in a Tedlar bag and sampled by electronic nose (Cyranose 320). Breathprints were analyzed with principal component analysis and individual factors were compared with mixed model analysis followed by pairwise comparisons. Inhalation of methacholine led to a 30.8 ± 3.3% fall in FEV(1) and was followed by a significant change in breathprint (p = 0.04). Saline inhalation did not induce a significant change in FEV(1), but altered the breathprint (p = 0.01). However, the breathprint obtained after the methacholine provocation was not significantly different from that after saline challenge (p = 0.27). The molecular profile of exhaled air in patients with asthma is altered by nebulized aerosols, but is not affected by acute changes in airway caliber. Our data demonstrate that breathprints by electronic nose are not confounded by the level of airway obstruction.
Collapse
Affiliation(s)
- Zsofia Lazar
- Department of Pulmonology, Semmelweis University, Diósárok u. 1/c, 1125 Budapest, Hungary
| | - Niki Fens
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; E-Mails: (N.F.); (M.P.D.S.); (A.H.W); (S.B.D.N.); (E.D.); (P.J.S.)
| | - Jan van der Maten
- Department of Pulmonology, Medical Centre Leeuwarden, PO Box 888, 8901 BR Leeuwarden, The Netherlands; E-Mail:
| | - Marc P. van der Schee
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; E-Mails: (N.F.); (M.P.D.S.); (A.H.W); (S.B.D.N.); (E.D.); (P.J.S.)
| | - Ariane H. Wagener
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; E-Mails: (N.F.); (M.P.D.S.); (A.H.W); (S.B.D.N.); (E.D.); (P.J.S.)
| | - Selma B. de Nijs
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; E-Mails: (N.F.); (M.P.D.S.); (A.H.W); (S.B.D.N.); (E.D.); (P.J.S.)
| | - Erica Dijkers
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; E-Mails: (N.F.); (M.P.D.S.); (A.H.W); (S.B.D.N.); (E.D.); (P.J.S.)
| | - Peter J. Sterk
- Department of Respiratory Medicine, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; E-Mails: (N.F.); (M.P.D.S.); (A.H.W); (S.B.D.N.); (E.D.); (P.J.S.)
| |
Collapse
|
11
|
Fens N, Zwinderman AH, van der Schee MP, de Nijs SB, Dijkers E, Roldaan AC, Cheung D, Bel EH, Sterk PJ. Exhaled breath profiling enables discrimination of chronic obstructive pulmonary disease and asthma. Am J Respir Crit Care Med 2009; 180:1076-82. [PMID: 19713445 DOI: 10.1164/rccm.200906-0939oc] [Citation(s) in RCA: 229] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Chronic obstructive pulmonary disease (COPD) and asthma can exhibit overlapping clinical features. Exhaled air contains volatile organic compounds (VOCs) that may qualify as noninvasive biomarkers. VOC profiles can be assessed using integrative analysis by electronic nose, resulting in exhaled molecular fingerprints (breathprints). OBJECTIVES We hypothesized that breathprints by electronic nose can discriminate patients with COPD and asthma. METHODS Ninety subjects participated in a cross-sectional study: 30 patients with COPD (age, 61.6 +/- 9.3 years; FEV(1), 1.72 +/- 0.69 L), 20 patients with asthma (age, 35.4 +/- 15.1 years; FEV(1) 3.32 +/- 0.86 L), 20 nonsmoking control subjects (age, 56.7 +/- 9.3 years; FEV(1), 3.44 +/- 0.76 L), and 20 smoking control subjects (age, 56.1 +/- 5.9 years; FEV(1), 3.58 +/- 0.78). After 5 minutes of tidal breathing through an inspiratory VOC filter, an expiratory vital capacity was collected in a Tedlar bag and sampled by electronic nose. Breathprints were analyzed by discriminant analysis on principal component reduction resulting in cross-validated accuracy values (accuracy). Repeatability and reproducibility were assessed by measuring samples in duplicate by two devices. MEASUREMENTS AND MAIN RESULTS Breathprints from patients with asthma were separated from patients with COPD (accuracy 96%; P < 0.001), from nonsmoking control subjects (accuracy, 95%; P < 0.001), and from smoking control subjects (accuracy, 92.5%; P < 0.001). Exhaled breath profiles of patients with COPD partially overlapped with those of asymptomatic smokers (accuracy, 66%; P = 0.006). Measurements were repeatable and reproducible. CONCLUSIONS Molecular profiling of exhaled air can distinguish patients with COPD and asthma and control subjects. Our data demonstrate a potential of electronic noses in the differential diagnosis of obstructive airway diseases and in the risk assessment in asymptomatic smokers. Clinical trial registered with www.trialregister.nl (NTR 1282).
Collapse
Affiliation(s)
- Niki Fens
- Department of Respiratory Medicine, F5-260, Academic Medical Centre, University of Amsterdam, P.O. Box 22700, Amsterdam NL-1100 DE, The Netherlands.
| | | | | | | | | | | | | | | | | |
Collapse
|