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Suojalehto H, Suuronen K, Cullinan P, Lindström I, Sastre J, Walusiak-Skorupa J, Munoz X, Talini D, Klusackova P, Moore V, Merget R, Svanes C, Mason P, dell'Omo M, Moscato G, Quirce S, Hoyle J, Sherson D, Preisser A, Seed M, Rifflart C, Godet J, de Blay F, Vandenplas O. Phenotyping Occupational Asthma Caused by Acrylates in a Multicenter Cohort Study. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2019; 8:971-979.e1. [PMID: 31678289 DOI: 10.1016/j.jaip.2019.10.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND While acrylates are well-known skin sensitizers, they are not classified as respiratory sensitizers although several cases of acrylate-induced occupational asthma (OA) have been reported. OBJECTIVE To evaluate the characteristics of acrylate-induced OA in a large series of cases and compare those with OA induced by other low-molecular-weight (LMW) agents. METHODS Jobs and exposures, clinical and functional characteristics, and markers of airway inflammation were analyzed in an international, multicenter, retrospective cohort of subjects with OA ascertained by a positive inhalation challenge to acrylates (n = 55) or other LMW agents (n = 418) including isocyanates (n = 125). RESULTS Acrylate-containing glues were the most prevalent products, and industrial manufacturing, dental work, and beauty care were typical occupations causing OA. Work-related rhinitis was more common in acrylate-than in isocyanate-induced asthma (P < .001). The increase in postchallenge fractional exhaled nitric oxide was significantly greater in acrylate-induced OA (26.0; 8.2 to 38.0 parts per billion [ppb]) than in OA induced by other LMW agents (3.0; -1.0 to 10.0 ppb; P < .001) or isocyanates (5.0; 2.0 to 16.0 ppb; P = .010). Multivariable models confirmed that OA induced by acrylates was significantly and independently associated with a postchallenge increase in fractional exhaled nitric oxide (≥17.5 ppb). CONCLUSIONS Acrylate-induced OA shows specific characteristics, concomitant work-related rhinitis, and exposure-related increases in fractional exhaled nitric oxide, suggesting that acrylates may induce asthma through different immunologic mechanisms compared with mechanisms through which other LMW agents may induce asthma. Our findings reinforce the need for a reevaluation of the hazard classification of acrylates, and further investigation of the pathophysiological mechanisms underlying their respiratory sensitizing potential.
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Affiliation(s)
| | - Katri Suuronen
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Paul Cullinan
- Department of Occupational and Environmental Medicine, Royal Brompton Hospital and Imperial College (NHLI), London, United Kingdom.
| | | | - Joaquin Sastre
- Department of Allergy, Fundacion Jimenez Dıaz and CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Jolanta Walusiak-Skorupa
- Department of Occupational Diseases and Environmental Health, Nofer Institute of Occupational Medicine, Lodz, Poland
| | - Xavier Munoz
- Hospital Vall d'Hebron, Universitat Autonoma de Barcelona and CIBER de Enfermedades Respiratorias (CIBERES), Barcelona, Spain
| | - Donatella Talini
- Cardio-Thoracic and Vascular Department, University of Pisa, Pisa, Italy
| | - Pavlina Klusackova
- Department of Occupational Medicine, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Vicky Moore
- Occupational Lung Disease Unit, Birmingham Heartlands Hospital, Birmingham, United Kingdom
| | - Rolf Merget
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA), Ruhr University, Bochum, Germany
| | - Cecilie Svanes
- Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway
| | - Paola Mason
- Department of Cardiac-Thoracic-Vascular Sciences and Public Health, University of Padova, Padova, Italy
| | - Marco dell'Omo
- Department of Medicine, Section of Occupational Medicine, Respiratory Diseases and Occupational and Environmental Toxicology, University of Perugia, Perugia, Italy
| | - Gianna Moscato
- Department of Public Health, Experimental and Forensic Medicine, Specialization School in Occupational Medicine, University of Pavia, Pavia, Italy
| | - Santiago Quirce
- Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ) and CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Jennifer Hoyle
- Department of Respiratory Medicine, North Manchester General Hospital, Manchester, United Kingdom
| | - David Sherson
- Department of Pulmonary Medicine and Occupational Medicine, Odense University Hospital, Odense, Denmark
| | - Alexandra Preisser
- Institute for Occupational and Maritime Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin Seed
- Centre for Occupational and Environmental Health, The University of Manchester, Manchester, United Kingdom
| | - Catherine Rifflart
- Department of Chest Medicine, Centre Hospitalier Universitaire UCL Namur, Université Catholique de Louvain, Yvoir, Belgium
| | - Julien Godet
- Groupe Méthode Recherche Clinique, Pôle de Santé Publique, Strasbourg University, Strasbourg, France
| | - Frédéric de Blay
- Division of Asthma and Allergy, Department of Chest Diseases, University Hospital of Strasbourg, Strasbourg, France; Fédération de Médecine translationnelle, Strasbourg University, Strasbourg, France
| | - Olivier Vandenplas
- Department of Chest Medicine, Centre Hospitalier Universitaire UCL Namur, Université Catholique de Louvain, Yvoir, Belgium
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Jendzjowsky NG, Kelly MM. The Role of Airway Myofibroblasts in Asthma. Chest 2019; 156:1254-1267. [PMID: 31472157 DOI: 10.1016/j.chest.2019.08.1917] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/14/2019] [Accepted: 08/11/2019] [Indexed: 12/17/2022] Open
Abstract
Airway remodeling is a characteristic feature of asthma and is thought to play an important role in the pathogenesis of airway hyperresponsiveness. Myofibroblasts are key structural cells involved in injury and repair, and there is evidence that dysregulation of their normal function contributes to airway remodeling. Despite the importance of myofibroblasts, a lack of specific cellular markers and inconsistent nomenclature have limited recognition of their key role in airway remodeling. Myofibroblasts are increased several-fold in the airways in asthma, in proportion to the severity of the disease. Myofibroblasts are postulated to be derived from both tissue-resident and bone marrow-derived cells, depending on the stage of injury and the tissue. A small number of studies have demonstrated attenuation of myofibroblast numbers and also reversal of established myofibroblast populations in asthma and other inflammatory processes. In this article, we review what is currently known about the biology of myofibroblasts in the airways in asthma and identify potential targets to reduce or reverse the remodeling process. However, further translational research is required to better understand the mechanistic role of the myofibroblast in asthma.
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Affiliation(s)
- Nicholas G Jendzjowsky
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Margaret M Kelly
- Airway Inflammation Research Group, Snyder Institute for Chronic Disease, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada; Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada.
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Nair P, Martin JG, Cockcroft DC, Dolovich M, Lemiere C, Boulet LP, O'Byrne PM. Airway Hyperresponsiveness in Asthma: Measurement and Clinical Relevance. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2017; 5:649-659.e2. [PMID: 28163029 DOI: 10.1016/j.jaip.2016.11.030] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 11/01/2016] [Indexed: 10/20/2022]
Abstract
Airway hyperresponsiveness is a characteristic feature of asthma, and its measurement is an important tool in its diagnosis. With a few caveats, methacholine bronchial provocation by a 2-minute tidal breathing method is highly sensitive; a negative test result (PC20 > 16 mg/mL, PD20 > 400 μg) rules out current asthma with reasonable certainty. A PC20 value of less than 1 mg/mL/PD20 value of less than 25 μg is highly specific (ie, diagnostic) but quite insensitive for asthma. For accurate interpretation of the test results, it is important to control and standardize technical factors that have an impact on nebulizer performance. In addition to its utility to relate symptoms such as cough, wheeze, and shortness of breath to variable airflow obstruction (ie, to diagnose current asthma), the test is useful to make a number of other clinical assessments. These include (1) evaluation of patients with occupational asthma, (2) evaluation of patients with exercise-induced respiratory symptoms, (3) evaluation of novel asthma medications, (4) evaluation of relative potency of inhaled bronchodilators, (5) as a biomarker to adjust anti-inflammatory therapy to improve clinical outcomes, and (6) in the evaluation of patients with severe asthma to rule out masqueraders such as laryngeal dysfunction. The actual mechanism of altered smooth muscle behavior in asthma that is assessed by direct (eg, methacholine) or indirect (eg, allergen) bronchial provocation remains one of the most fundamental questions related to asthma that needs to be determined. The test is underutilized in clinical practice.
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Affiliation(s)
- Parameswaran Nair
- Division of Respirology, Department of Medicine, McMaster University and St Joseph's Healthcare, Hamilton, Ontario, Canada.
| | - James G Martin
- Meakins Christie Laboratories and Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Donald C Cockcroft
- Division of Respirology, Department of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Myrna Dolovich
- Division of Respirology, Department of Medicine, McMaster University and St Joseph's Healthcare, Hamilton, Ontario, Canada
| | - Catherine Lemiere
- Department of Medicine, Sacre Coeur Hospital, University of Montreal, Montreal, Quebec, Canada
| | - Louis-Philippe Boulet
- Division of Respirology, Department of Medicine, University of Laval, Laval, Quebec, Canada
| | - Paul M O'Byrne
- Division of Respirology, Department of Medicine, McMaster University and St Joseph's Healthcare, Hamilton, Ontario, Canada
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Abstract
BACKGROUND The diagnosis of occupational asthma (OA) can be challenging and needs a stepwise approach. However, the predictive value of the methacholine challenge has never been addressed specifically in this context. OBJECTIVE We sought to evaluate the sensitivity, specificity, and positive and negative predictive values of the methacholine challenge in OA. METHODS A Canadian database was used to review 1012 cases of workers referred for a suspicion of OA between 1983 and 2011 and having had a specific inhalation challenge. We calculated the sensitivity, specificity, and positive and negative predictive values of methacholine challenges at baseline of the specific inhalation challenge, at the workplace, and outside work. RESULTS At baseline, the methacholine challenge showed an overall sensitivity of 80.2% and a specificity of 47.1%, with positive and negative predictive values of 36.5% and 86.3%, respectively. Among the 430 subjects who were still working, the baseline measures displayed a sensitivity of 95.4%, a specificity of 40.1%, and positive and negative predictive values of 41.1% and 95.2%, respectively. Among the 582 subjects tested outside work, the baseline measures demonstrated a sensitivity and specificity of 66.7% and 52%, respectively, and positive and negative predictive values of 31.9% and 82.2%, respectively. When considering all subjects tested by a methacholine challenge at least once while at work (479), the sensitivity, specificity, and positive and negative predictive values were 98.1%, 39.1%, and 44.0% and 97.7%, respectively. CONCLUSION A negative methacholine challenge in a patient still exposed to the causative agent at work makes the diagnosis of OA very unlikely.
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Advanced diagnostic studies: exhaled breath and sputum analyses. J Occup Environ Med 2015; 56 Suppl 10:S45-8. [PMID: 25285976 DOI: 10.1097/jom.0000000000000286] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AIM : The present paper aims to review the advantages and limitations of sputum cell counts and exhaled nitric oxide (FeNO) levels in the investigation of occupational asthma (OA). METHODS The American College of Chest physicians held a course on occupational and Environmental Lung Diseases in Toronto in 2013. A summary of the session on non-invasive measures of airway inflammation in OA is presented here. RESULTS Occupational asthma is associated with an increase in sputum eosinophil percentage during periods at work or after positive specific inhalation challenges. Changes in FeNO are less sensitive than sputum eosinophil counts for predicting OA. CONCLUSIONS In settings where this tool is available, sputum eosinophil counts may complement the current investigation of OA. The interpretation of FeNO remains sometimes difficult. The phenotypes of patients who may benefit from this measure needs to be better defined.
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Long-term socioprofessional and psychological status in workers investigated for occupational asthma in quebec. J Occup Environ Med 2014; 55:1052-64. [PMID: 23969504 DOI: 10.1097/jom.0b013e31829904ab] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the long-term status of workers with occupational asthma (OA) with those of subjects with work-exacerbated asthma (WEA) and nonasthmatic (NA) workers. METHODS We contacted 179 subjects investigated for suspected OA at Hôpital du Sacré-Coeur de Montréal, Montreal, Quebec, Canada, from 1997 to 2007. Participants completed questionnaires on psychological and functional status, followed by a telephone interview about socioprofessional outcomes and health care utilization. RESULTS The OA workers are more likely to have been removed from the workplace than the WEA workers. The health-related quality of life of all workers was still impaired. A high prevalence of psychiatric disorders was found among OA and WEA workers. Compared with WEA and OA workers, the NA group showed a higher rate of physician consultations for all causes. CONCLUSIONS Regardless of the diagnosis they received, these workers need to benefit from psychosocial support in the period after investigation for suspicion of OA.
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Malo JL, Vandenplas O. Definitions and classification of work-related asthma. Immunol Allergy Clin North Am 2012; 31:645-62, v. [PMID: 21978849 DOI: 10.1016/j.iac.2011.07.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The workplace can trigger or induce asthma and cause the onset of different types of work-related asthma (WRA). Based on current knowledge of clinical features, pathophysiologic mechanisms, and evidence supporting a causal relationship, the following conditions should be distinguished in the spectrum of WRA: (1) immunologic occupational asthma (OA), (2) nonimmunologic OA, (3) work-exacerbated asthma, and (4) variant syndromes, including eosinophilic bronchitis, potroom asthma, and asthmalike disorders caused by organic dusts. The rationale, issues, and controversies relating to this approach are critically reviewed to stimulate the development of a consensus on operational definitions of the various phenotypes of WRA.
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Affiliation(s)
- Jean-Luc Malo
- Department of Chest Medicine, Hôpital du Sacré-Cœur, Université de Montréal, 5400 West Gouin Boulevard, Montreal H4J 1C5, Canada.
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Nam YH, Kim JI, Um SJ, Lee SK, Son CH. Absence of hyper-responsiveness to methacholine after specific bronchial provocation tests in a worker with hydroxyapatite-induced occupational asthma. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2011; 3:135-7. [PMID: 21461255 PMCID: PMC3062794 DOI: 10.4168/aair.2011.3.2.135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 11/24/2010] [Indexed: 12/05/2022]
Abstract
Hydroxyapatite is commonly used as a filler to replace amputated bone or as a coating to promote bone ingrowth into prosthetic implants. Many modern implants, such as hip replacements and dental implants, are coated with hydroxyapatite. We report a patient with occupational asthma due to hydroxyapatite, proven by a specific inhalation challenge, who experienced an early asthmatic reaction after exposure to hydroxyapatite, without increased airway responsiveness to methacholine despite an increased eosinophil count in the peripheral blood. A 38-year-old male dental implant worker visited our allergy department for the evaluation of occupational asthma. He had treated dental implant titanium surfaces with hydroxyapatite for 1.5 years. One year after starting his employment, he noticed symptoms of rhinorrhea, paroxysmal cough, and chest tightness. His symptoms were aggravated during and shortly after work and subsided several hours after work. When he stopped working for 2 months because of his chest symptoms, he became asymptomatic. After restarting his work, his symptoms reappeared and were aggravated. A methacholine bronchial challenge test had a negative response. The following day, a specific bronchial provocation test with wheat powder was negative. On the third day, a specific bronchial provocation test with hydroxyapatite powder produced an early asthmatic response. On the fourth day, a methacholine bronchial challenge test was negative. Further studies are needed to evaluate the exact pathogenetic mechanism of hydroxyapatite-induced occupational asthma.
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Affiliation(s)
- Young-Hee Nam
- Department of Internal Medicine, College of Medicine, Dong-A University, Busan, Korea
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Quirce S, Lemière C, de Blay F, del Pozo V, Gerth Van Wijk R, Maestrelli P, Pauli G, Pignatti P, Raulf-Heimsoth M, Sastre J, Storaas T, Moscato G. Noninvasive methods for assessment of airway inflammation in occupational settings. Allergy 2010; 65:445-58. [PMID: 19958319 DOI: 10.1111/j.1398-9995.2009.02274.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The present document is a consensus statement reached by a panel of experts on noninvasive methods for assessment of airway inflammation in the investigation of occupational respiratory diseases, such as occupational rhinitis, occupational asthma, and nonasthmatic eosinophilic bronchitis. Both the upper and the lower airway inflammation have been reviewed and appraised reinforcing the concept of 'united airway disease' in the occupational settings. The most widely used noninvasive methods to assess bronchial inflammation are covered: induced sputum, fractional exhaled nitric oxide (FeNO) concentration, and exhaled breath condensate. Nasal inflammation may be assessed by noninvasive approaches such as nasal cytology and nasal lavage, which provide information on different aspects of inflammatory processes (cellular vs mediators). Key messages and suggestions on the use of noninvasive methods for assessment of airway inflammation in the investigation and diagnosis of occupational airway diseases are issued.
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Affiliation(s)
- S Quirce
- Department of Allergy, Hospital La Paz, Madrid, Spain
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Vandenplas O, D'Alpaos V, Heymans J, Jamart J, Thimpont J, Huaux F, Lison D, Renauld JC. Sputum eosinophilia: an early marker of bronchial response to occupational agents. Allergy 2009; 64:754-61. [PMID: 19220213 DOI: 10.1111/j.1398-9995.2008.01896.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND False-negative responses to specific inhalation challenge (SIC) with occupational agents may occur. We explored whether assessing changes in sputum cell counts would help improve the identification of bronchial reactivity to occupational agents during SICs. METHODS The predictive value of the changes in sputum cell counts after a negative FEV(1) response to a first challenge exposure to an occupational agent was determined using the changes in airway calibre observed during repeated challenges as the 'gold standard'. The study included 68 subjects investigated for work-related asthma in a tertiary centre. After a control day, the subjects were challenged with the suspected occupational agent(s) for up to 2 h. All subjects who did not show an asthmatic reaction were re-challenged on the following day. Additional challenges were proposed to those who demonstrated a > or = 2% increase in sputum eosinophils or an increase in nonspecific bronchial hyperresponsiveness to histamine after the second challenge day. RESULTS Six of the 35 subjects without changes in FEV(1) on the first challenge developed an asthmatic reaction on subsequent challenges. ROC analysis revealed that a >3% increase in sputum eosinophils at the end of the first challenge day was the most accurate parameter for predicting the development of an asthmatic response on subsequent challenges with a sensitivity of 67% and a specificity of 97%. CONCLUSIONS An increase in sputum eosinophils is an early marker of specific bronchial reactivity to occupational agents, which may help to identify subjects who will develop an asthmatic reaction only after repeated exposure.
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Affiliation(s)
- O Vandenplas
- Department of Chest Medicine, Mont-Godinne Hospital, Université Catholique de Louvain, Yvoir, Belgium
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Pauluhn J. Brown Norway rat asthma model of diphenylmethane-4,4'-diisocyanate (MDI): analysis of the elicitation dose-response relationship. Toxicol Sci 2008; 104:320-31. [PMID: 18495671 DOI: 10.1093/toxsci/kfn098] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The known human asthmagen polymeric diphenylmethane-diisocyanate (MDI) was investigated in the Brown Norway rat skin asthma model. Two types of dose-response relationships are addressed with the following focus: (1) does sensitization dose and surface area influence the subsequent elicitation response and (2) is the elicitation response more dependent on previous elicitation doses or more on skin sensitizing dose? These two aims are investigated in two elaborated experiments, using inflammatory (bronchoalveolar lavage, BAL) and physiologic (Penh) endpoints to characterize asthma-like responses in rats. Postchallenge measurements of Penh focused on responses delayed in onset. Inflammatory endpoints in BAL were performed one day after the fourth challenge. Both protocols utilized a dermal sensitization phase with two administrations on days 0 and 7 followed by four inhalation challenges with approximately 38 mg MDI/m(3) in intervals of 2 weeks. In the first protocol three groups of rats were topically dosed with 40, 10, and 2.5 mul of MDI per rat. Each dose group consisted of three subgroups with dosed surface areas of 3.1-12.6 cm(2), 0.8-3.1 cm(2), and 0.4-0.8 cm(2), respectively. In the second protocol groups of rats were topically dosed with 40 microl of MDI per rat followed by three challenges with 37 mg MDI/m(3). At the fourth challenge subgroups of rats were either challenged with 8, 18, or 39 mg MDI/m(3). Independent of the protocol used, response was characterized by increased influx of neutrophilic granulocytes in BAL and delayed respiratory response. All groups from the first study sensitized to and challenged with MDI elicited a distinct response relative to similarly challenged naive rats. A sensitization dose dependence of the elicitation response was not found. The second protocol revealed that the elicitation dose correlates with increased neutrophils in BAL and delayed-onset respiratory responses. In summary, these data suggest that the vigor of asthma-like responses appear to be more dependent on the inhalation elicitation dose of previously challenged rats rather than the dermal induction dose.
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Affiliation(s)
- Jürgen Pauluhn
- Institute of Toxicology, Bayer HealthCare, 42096 Wuppertal, Germany.
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Ishiura Y, Fujimura M, Nobata K, Oribe Y, Abo M, Myou S, Nonomura A. In vivo PAF-induced airway eosinophil accumulation reduces bronchial responsiveness to inhaled histamine. Prostaglandins Other Lipid Mediat 2005; 75:1-12. [PMID: 15789611 DOI: 10.1016/j.prostaglandins.2004.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chronic eosinophilic bronchitis and bronchial hyperresponsiveness have been considered to be the fundamental features of bronchial asthma. However, the role of airway eosinophils in bronchial responsiveness in vivo has not been fully discussed. The aim of this study was to investigate the direct effect of airway eosinophil accumulation on bronchial responsiveness in vivo. Guinea pigs were transnasally treated with platelet activating factor (PAF) or vehicle twice a week for a total of 3 weeks. Anesthetized guinea pigs were surgically cannulated and artificially ventilated 48 h after the last administration of PAF or vehicle. Ten minutes after the installation of artificial ventilation, ascending doses of histamine were inhaled. In a subsequent study, selective inhibitors of diamine oxidase and histamine N-methyltransferase were intravenously administered before the histamine inhalation in the PAF-treated animals. Next study was conducted 20 min after treatment with indomethacin in this study line. Finally, ascending doses of methacholine were inhaled in our animal model. Proportion of eosinophils and the number of nuclear segmentation in bronchoalveolar lavage fluid significantly increased in guinea pigs treated with PAF compared with vehicle and this finding was confirmed histologically. Nevertheless, bronchial responsiveness to inhaled histamine, but not methacholine, was significantly decreased by the PAF treatment. This bronchoprotective effect induced by PAF remained following aminoguanidine and histamine N-methyltransferase administration, but abolished by treatment of indomethacin. These results suggest that in vivo airway eosinophils may reduce nonspecific bronchial responsiveness through production of inhibitory or bronchoprotective prostanoids, but not through histaminase production.
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Affiliation(s)
- Yoshihisa Ishiura
- Respiratory Medicine, Cellular Transplantation Biology, Kanazawa Graduate University School of Medicine, Kanazawa, Japan. ishiura-@p2322.nsk.ne.jp
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Abstract
PURPOSE OF REVIEW The purpose of this review is to report that eosinophilic bronchitis without asthma may occur as an occupational airway disease. This condition is characterized by cough that is responsive to corticosteroids and eosinophilia detectable in the sputum, without variable airflow obstruction or airway hyperresponsiveness. RECENT FINDINGS Eosinophilic bronchitis can be regarded as an occupational respiratory disorder when it develops as a consequence of work exposures. Recently, exposure to certain occupational allergens or sensitizers, such as natural rubber latex, mushroom spores, acrylates and an epoxy resin hardener, have been reported to cause eosinophilic bronchitis without asthma. Several hypotheses have been put forward trying to explain why patients with eosinophilic bronchitis do not have airway hyperresponsiveness. It is unknown whether eosinophilic bronchitis may progress to typical occupational asthma, or if eosinophilic airway inflammation may persist when asthma symptoms and airway hyperresponsiveness have waned after the cessation of exposure to the occupational agent. SUMMARY Eosinophilic bronchitis, like asthma, may arise from occupational exposures. The examination of induced sputum should be added to the objective monitoring of lung function during periods at work and away from work, as well as before and after specific inhalation challenges with occupational agents.
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Affiliation(s)
- J-L Malo
- Department of Chest Medicine Sacré-Coeur Hospital 5400 Gouin Blvd West Montreal (Qué) Canada H4J 1C5.
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Gibson PG, Henry RL, Shah S, Powell H, Wang H. Migration to a western country increases asthma symptoms but not eosinophilic airway inflammation. Pediatr Pulmonol 2003; 36:209-15. [PMID: 12910582 DOI: 10.1002/ppul.10323] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The prevalence of asthma symptoms varies markedly throughout the world. However, the asthma mechanisms involved are not defined. Studying the effects of migration can help identify the reasons for this geographic variation. The aims of this study were to examine the prevalence of asthma symptoms, airway hyperresponsiveness (AHR), and induced sputum eosinophils in adolescents who migrate to Australia. The study was conducted in Sydney, Australia, where adolescent students completed a video symptom questionnaire, hypertonic saline challenge, sputum induction, and allergy skin testing. The 211 students had widely different cultural backgrounds, including Asian, South Pacific, Middle Eastern, European, and African countries. Among adolescents who were migrants to Australia, the prevalence of asthma symptoms was higher than that reported using a similar methodology in their country of origin. Asthma symptom prevalence was related to residence time in Australia. The prevalence of wheeze was 17.2% in recent arrivals, 20.5% in adolescents living in Australia for >2 years, and 36.3% in those living all their lifetime in Australia (P = 0.013). For every year of residence in Australia, there was an 11% increase in prevalence of current wheeze (odds ratio, 1.11; P = 0.02). This effect was not related to atopy, AHR, or eosinophilic airway inflammation. Sputum neutrophils were elevated in recent arrivals. In conclusion, adolescents who migrate to Australia report increased asthma symptoms, compared to their country of origin, and asthma symptoms are further increased for every additional year of residence in Australia. The development of wheeze after migration to Australia was independent of eosinophilic inflammation and consistent with noneosinophilic asthma mechanisms.
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Affiliation(s)
- Peter G Gibson
- Hunter Medical Research Institute, University of Newcastle, John Hunter Hospital, Newcastle, New South Wales, Australia.
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Malo JL. Utilization of pulmonary function measurements in the assessment of occupational asthma. Curr Opin Allergy Clin Immunol 2002; 2:93-5. [PMID: 11964755 DOI: 10.1097/00130832-200204000-00002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Lung function assessments that include spirometry and bronchial responsiveness are now often coupled to immunological assessment and an evaluation of inflammation in the investigation of occupational asthma. For diagnostic purposes, evidence points out that specific inhalation challenges are the gold standard, as previously suspected. In the epidemiological setting, both spirometry and bronchial responsiveness are feasible and safe. The role of lung function assessments in surveillance programmes is still open to discussion.
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Affiliation(s)
- Jean-Luc Malo
- Department of Chest Medicine, Hôpital de Sacré-Coeur de Montréal, Canada.
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Quirce S, Baeza ML, Tornero P, Blasco A, Barranco R, Sastre J. Occupational asthma caused by exposure to cyanoacrylate. Allergy 2001; 56:446-9. [PMID: 11350310 DOI: 10.1034/j.1398-9995.2001.056005446.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Exposure to acrylates may give rise to rhinitis and asthma in both industrial and domestic environments. The mechanisms underlying these respiratory conditions caused by acrylates remain largely unknown. METHODS We studied two assembly operators exposed to cyanoacrylate glue who developed rhinitis and asthma symptoms. The causal relationship of these symptoms to cyanoacrylate glue exposure was investigated by serial peak expiratory flow (PEF) monitoring at work and off work. Moreover, inhalation testing was performed by asking the patients to mimic exposure at work with the cyanoacrylate glue in a 7-m3 challenge chamber. RESULTS Serial PEF monitoring at work and away from work was consistent with occupational asthma in both patients. The methacholine inhalation test was negative in patient 1 (off work) and showed bronchial hyperresponsiveness in patient 2. After 20-min exposure to cyanoacrylate, the patients had late and progressive asthmatic reactions, respectively, and the methacholine test became positive in patient 1. Induced-sputum samples obtained 3 and 24 h after the cyanoacrylate challenge showed a marked increase in sputum eosinophils. CONCLUSION Exposure to cyanoacrylate in these patients provoked not only variable airflow limitation and bronchial hyperresponsiveness, but also pronounced eosinophilia in sputum.
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Affiliation(s)
- S Quirce
- Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, Spain
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