RESUMO
BACKGROUND: Assessment of IgE-mediated sensitization to flour allergens is widely used to investigate flour-induced occupational asthma. The diagnostic efficiency of detecting specific IgE antibodies (sIgEs) against wheat and rye flour, however, has not been thoroughly compared with other diagnostic procedures. OBJECTIVE: We sought to evaluate the diagnostic accuracy of sIgE against wheat and rye compared with specific inhalation challenge (SIC) with flour as the reference standard. METHODS: This retrospective multicenter study included 264 subjects who completed an SIC with flour in eight tertiary centers, of whom 205 subjects showed a positive SIC result. RESULTS: Compared with SIC, sIgE levels of 0.35 kUA/L or greater against wheat and rye provided similar sensitivities (84% to 85%, respectively), specificities (71% to 78%), positive predictive values (91% to 93%), and negative predictive values (56% to 61%). Increasing the threshold sIgE value to 5.10 kUA/L for wheat and to 6.20 kUA/L for rye provided a specificity of 95% or greater and further enhanced the positive predictive value to 98%. Among subjects with a positive SIC, those who failed to demonstrate sIgE against wheat and rye (n = 26) had significantly lower total serum IgE level and blood and sputum eosinophil counts and a lesser increase in postchallenge FeNO compared with subjects with a detectable sIgE. CONCLUSION: High levels of sIgE against wheat and/or rye flour strongly support a diagnosis of flour-induced occupational asthma without the need to perform an SIC. The absence of detectable sIgE against wheat and rye in subjects with a positive SIC seems to be associated with lower levels of TH2 biomarkers.
Assuntos
Asma Ocupacional , Farinha , Imunoglobulina E , Secale , Triticum , Humanos , Secale/imunologia , Secale/efeitos adversos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Masculino , Asma Ocupacional/diagnóstico , Asma Ocupacional/imunologia , Feminino , Farinha/efeitos adversos , Adulto , Estudos Retrospectivos , Triticum/imunologia , Triticum/efeitos adversos , Pessoa de Meia-Idade , Alérgenos/imunologia , Testes de Provocação Brônquica , Sensibilidade e Especificidade , Hipersensibilidade a Trigo/imunologia , Hipersensibilidade a Trigo/diagnósticoRESUMO
INTRODUCTION: The many substances used at the workplace that can cause sensitizer-induced occupational asthma are conventionally categorized into high-molecular-weight (HMW) agents and low-molecular-weight (LMW) agents, implying implicitly that these two categories of agents are associated with distinct phenotypic profiles and pathophysiological mechanisms. AREAS COVERED: The authors conducted an evidence-based review of available data in order to identify the similarities and differences between HMW and LMW sensitizing agents. EXPERT OPINION: Compared with LMW agents, HMW agents are associated with a few distinct clinical features (i.e. concomitant work-related rhinitis, incidence of immediate asthmatic reactions and increase in fractional exhaled nitric oxide upon exposure) and risk factors (i.e. atopy and smoking). However, some LMW agents may exhibit 'HMW-like' phenotypic characteristics, indicating that LMW agents are a heterogeneous group of agents and that pooling them into a single group may be misleading. Regardless of the presence of detectable specific IgE antibodies, both HMW and LMW agents are associated with a mixed Th1/Th2 immune response and a predominantly eosinophilic pattern of airway inflammation. Large-scale multicenter studies are needed that use objective diagnostic criteria and assessment of airway inflammatory biomarkers to identify the pathobiological pathways involved in OA caused by the various non-protein agents.
Assuntos
Asma Ocupacional , Peso Molecular , Exposição Ocupacional , Humanos , Asma Ocupacional/imunologia , Asma Ocupacional/diagnóstico , Exposição Ocupacional/efeitos adversos , Imunoglobulina E/imunologia , Imunoglobulina E/sangue , Alérgenos/imunologia , Células Th2/imunologia , Fatores de RiscoRESUMO
BACKGROUND: The impact of work-related asthma (WRA) on quality of life (QoL) and work productivity remains largely neglected/uncertain despite its high prevalence. OBJECTIVE: To investigate the association of WRA with QoL and work productivity as compared with subjects with non-WRA and those without asthma and rhinitis. METHODS: A cross-sectional survey was carried out among workers during their periodic occupational health visit in Belgium. The Mini Asthma Quality of Life Questionnaire, the 8-item Medical Outcome Study Short Form instrument, and the Work Productivity and Activity Impairment-General Health questionnaire were administered. Survey participants were divided into 3 groups: (1) WRA (current asthma with ≥2 respiratory symptoms at work; n = 89); (2) non-WRA (current asthma without work-related respiratory symptoms; n = 119); and (3) the reference group (no asthma and no lower respiratory, nasal, or eye symptoms; n = 815). Associations of QoL and work productivity with WRA were evaluated by multivariable regression analyses. RESULTS: WRA and having poor asthma control were significantly associated with lower global Mini Asthma Quality of Life Questionnaire scores compared with non-WRA. Asthmatic subjects had significantly lower physical and mental health component scores of the 8-item Medical Outcome Study Short Form instrument and overall work productivity compared with the reference group, with greater impairment in workers with WRA than in those without WRA. Moreover, workers with WRA had higher percentages of doctor visits and income reduction because of respiratory symptoms than those with non-WRA. Work-related rhinitis and depression were associated with reduced QoL, independent of the effect of WRA. CONCLUSIONS: WRA should be managed comprehensively to reduce the worsening of QoL and work productivity of those affected.
Assuntos
Asma Ocupacional , Asma , Doenças Profissionais , Rinite , Humanos , Qualidade de Vida , Estudos Transversais , Asma/diagnóstico , Rinite/complicações , Asma Ocupacional/epidemiologiaRESUMO
Irritant-induced asthma (IIA) is a phenotype of asthma caused by the inhalation of irritant agents. Definite, probable, or possible IIA have been described, depending on the concentration of the inhaled irritants and the onset of respiratory symptoms respective to the time of exposure. Definite IIA represents approximately 4% to 14% of all cases of new-onset work-related asthma. Agents responsible for IIA can be encountered as fumes, gases, aerosols, or dusts. The most frequent are chlorine, nitrogen oxides, sulfur dioxide, ammonia, acetic acid, solvents, and cleaning materials. Although the diagnosis of definite IIA is based on a suggestive clinical history along with evidence of reversible airflow limitation and/or nonspecific bronchial hyperresponsiveness, possible IIA cannot be diagnosed with certainty because the relationship between exposure and the onset of symptoms is difficult to establish. This article reviews the epidemiology, pathophysiology, diagnostic approach, and management of IIA.
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Asma , Hiper-Reatividade Brônquica , Doenças Profissionais , Exposição Ocupacional , Humanos , Irritantes/efeitos adversos , Asma/diagnóstico , Asma/epidemiologia , Asma/etiologiaRESUMO
BACKGROUND: Quaternary ammonium compounds (QACs) are used extensively for cleaning and disinfection and have been documented in scattered reports as a cause of occupational asthma (OA) through bronchoprovocation tests (BPTs). OBJECTIVE: To examine the clinical, functional, and inflammatory profile of QAC-induced OA compared with OA caused by other low-molecular weight (LMW) agents. METHODS: The study was conducted in a retrospective multicenter cohort of 871 subjects with OA ascertained by a positive BPT. Subjects with QAC-induced OA (n = 22) were identified based on a positive BPT to QACs after exclusion of those challenged with cleaning products or disinfectants that contained other potential respiratory sensitizers. They were compared with 289 subjects with OA caused by other LMW agents. RESULTS: Most subjects with QAC-induced OA were working in the health care sector (n = 14). A twofold or greater increase in the postchallenge level of nonspecific bronchial hyperresponsiveness was recorded in eight of 11 subjects with QAC-induced OA (72.7%) and in 49.7% of those with OA caused by other LMW agents. Although sputum assessment was available in only eight subjects with QAC-induced OA, they showed a significantly greater median (interquartile) increase in sputum eosinophils (18.1% [range, 12.1% to 21.1%]) compared with those with OA caused by other LMW agents (2.0% [range, 0% to 5.2%]; P < .001). CONCLUSIONS: This study indicates that QAC-induced OA is associated with a highly eosinophilic pattern of airway response and provides further evidence supporting the sensitizing potential of QACs. The findings highlight the heterogeneous nature of the pathobiologic pathways involved in OA caused by LMW agents.
Assuntos
Asma Ocupacional , Asma Ocupacional/induzido quimicamente , Asma Ocupacional/diagnóstico , Estudos de Coortes , Eosinófilos , Humanos , Compostos de Amônio Quaternário , Estudos RetrospectivosRESUMO
BACKGROUND: Occupational eosinophilic bronchitis (OEB) has been described only as anecdotal case reports. OBJECTIVE: We investigated the clinical and inflammatory characteristics of subjects with OEB identified in a cohort of subjects who completed a specific inhalation challenge (SIC) with occupational agents. METHODS: In this retrospective multicenter study, OEB was defined by (1) a fall in FEV1 less than 15% during the SIC and the absence of nonspecific bronchial hyperresponsiveness both before and after the SIC and (2) a postchallenge increase of 3% or more in sputum eosinophils. The subjects who fulfilled these criteria were compared with 226 subjects with a negative SIC and 30 subjects with a positive SIC who failed to show baseline nonspecific bronchial hyperresponsiveness. RESULTS: An isolated increase in postchallenge sputum eosinophils was documented in 33 of 259 subjects (13%) with a negative SIC. These subjects reported significantly more often an isolated cough at work compared with the negative and positive SIC controls. When compared with positive SIC controls, the subjects with OEB experienced less frequently work-related wheezing and reported a shorter duration of symptoms at work. The sensitivity of the post-SIC increase in fractional exhaled nitric oxide in identifying OEB among subjects with a negative SIC was low, ranging from 43% to 24% using cutoff values of 8 ppb to 17.5 ppb, whereas the specificity was high (90%-97%). CONCLUSIONS: This study highlights the relevance of induced sputum analysis in the investigation of work-related asthma symptoms to identify isolated increases in sputum eosinophils that are consistent with a diagnosis of OEB.
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Asma Ocupacional , Asma , Bronquite , Asma Ocupacional/diagnóstico , Bronquite/diagnóstico , Eosinófilos , Expiração , Humanos , Óxido Nítrico , Estudos Retrospectivos , EscarroRESUMO
Exposures at work can give rise to different phenotypes of "work-related asthma." The focus of this review is on the diagnosis and management of sensitizer-induced occupational asthma (OA) caused by either a high- or low-molecular-weight agent encountered in the workplace. The diagnosis of OA remains a challenge for the clinician because there is no simple test with a sufficiently high level of accuracy. Instead, the diagnostic process combines different procedures in a stepwise manner. These procedures include a detailed clinical history, immunologic testing, measurement of lung function parameters and airway inflammatory markers, as well as various methods that relate changes in these functional and inflammatory indices to workplace exposure. Their diagnostic performances, alone and in combination, are critically reviewed and summarized into evidence-based key messages. A working diagnostic algorithm is proposed that can be adapted to the suspected agent, purpose of diagnosis, and available resources. Current information on the management options of OA is summarized to provide pragmatic guidance to clinicians who have to advise their patients with OA.
Assuntos
Asma Ocupacional , Doenças Profissionais , Exposição Ocupacional , Asma Ocupacional/diagnóstico , Asma Ocupacional/terapia , Biomarcadores , Humanos , Exposição Ocupacional/efeitos adversos , Local de TrabalhoRESUMO
There is convincing evidence that tight relationships between the upper and lower airways also apply to the workplace context. Most patients with occupational asthma (OA) also suffer from occupational rhinitis (OR), although OR is 2 to 3 times more common than OA. OR most often precedes the development of OA, especially when high-molecular-weight protein agents are involved, and longitudinal cohort studies have confirmed that OR is associated with an increased risk for the development of OA. The level of exposure to sensitizing agents at the workplace is the most important determinant for the development of IgE-mediated sensitization and OR. Atopy is a risk factor for the development of IgE-mediated sensitization only to high-molecular-weight agents. In workers with work-related rhinitis symptoms, documentation of IgE-mediated sensitization to a workplace agent via skin prick testing or serum specific IgE confirms a diagnosis of probable OR, whereas specific nasal provocation testing in the laboratory remains the reference method to establish a definite diagnosis of OR. Complete avoidance of exposure to the causal agent is the most effective therapeutic option for controlling work-related nasal symptoms and preventing the development of OA. If complete elimination of exposure is expected to induce meaningful adverse socioeconomic consequences, reduction of exposure can be considered as an alternative approach, but it is important to consider the individual risk factors for the development of OA to implement a more personalized management of OR.
Assuntos
Asma Ocupacional , Doenças Profissionais , Exposição Ocupacional , Rinite , Asma Ocupacional/diagnóstico , Asma Ocupacional/epidemiologia , Humanos , Imunoglobulina E , Estudos Longitudinais , Doenças Profissionais/diagnóstico , Doenças Profissionais/epidemiologia , Exposição Ocupacional/efeitos adversos , Rinite/diagnóstico , Rinite/epidemiologiaAssuntos
Aspergilose Broncopulmonar Alérgica , Asma , Anticorpos Monoclonais Humanizados , Aspergilose Broncopulmonar Alérgica/diagnóstico , Aspergilose Broncopulmonar Alérgica/tratamento farmacológico , Aspergilose Broncopulmonar Alérgica/epidemiologia , Asma/tratamento farmacológico , Asma/epidemiologia , Bélgica/epidemiologia , Humanos , Sistema de RegistrosRESUMO
BACKGROUND: The specific burden of work-related rhinitis (WRR) on quality of life (QoL) and work productivity has received little attention. OBJECTIVE: The aim of this study was to investigate to what extent WRR affects QoL and work productivity as compared with subjects with rhinitis unrelated to work and those without rhinitis. METHODS: This cross-sectional survey was conducted among workers randomly recruited at the time of their periodic occupational health visit in the French-speaking part of Belgium. The survey instruments consisted of rhinitis-specific and generic questionnaires: Mini-Rhinitis QoL Questionnaire, Medical Outcome Study Short Form-8, and Work Productivity and Activity Impairment-General Health questionnaire. Eligible participants were categorized into 3 groups: non-WRR (current nasal symptoms not related to work, n = 329); WRR (current rhinitis with ≥2 nasal symptoms at work, n = 161); and controls (no nasal symptom; n = 1155). RESULTS: WRR showed significantly lower scores in all domains of the Mini-Rhinitis QoL Questionnaire compared with non-WRR. Multivariate analysis confirmed that WRR exerted an independent adverse effect on rhinitis-specific QoL. Both WRR and non-WRR were associated with greater impairment in the physical and mental health components of the Medical Outcome Study Short Form-8 instrument and the overall work productivity compared with controls, whereas these outcomes were more impacted in WRR than non-WRR. Multivariate analyses demonstrated that both WRR and non-WRR had an independent adverse impact on the physical and mental health status and overall work productivity. CONCLUSION: WRR has an incremental adverse impact on QoL and work productivity that should be addressed in order to reduce the global burden of rhinitis.
Assuntos
Qualidade de Vida , Rinite , Bélgica/epidemiologia , Estudos Transversais , Humanos , Rinite/epidemiologia , Inquéritos e Questionários , Recursos HumanosRESUMO
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.
Assuntos
Asma Ocupacional , Acrilatos/efeitos adversos , Asma Ocupacional/epidemiologia , Estudos de Coortes , Expiração , Humanos , Óxido Nítrico , Estudos RetrospectivosRESUMO
BACKGROUND: Although sensitizer-induced occupational asthma (OA) accounts for an appreciable fraction of adult asthma, the severity of OA has received little attention. OBJECTIVE: The aim of this study was to characterize the burden and determinants of severe OA in a large multicenter cohort of subjects with OA. METHODS: This retrospective study included 997 subjects with OA ascertained by a positive specific inhalation challenge completed in 20 tertiary centers in 11 European countries during the period 2006 to 2015. Severe asthma was defined by a high level of treatment and any 1 of the following criteria: (1) daily need for a reliever medication, (2) 2 or more severe exacerbations in the previous year, or (3) airflow obstruction. RESULTS: Overall, 162 (16.2%; 95% CI, 14.0%-18.7%) subjects were classified as having severe OA. Multivariable logistic regression analysis revealed that severe OA was associated with persistent (vs reduced) exposure to the causal agent at work (odds ratio [OR], 2.78; 95% CI, 1.50-5.60); a longer duration of the disease (OR, 1.04; 95% CI, 1.00-1.07); a low level of education (OR, 2.69; 95% CI, 1.73-4.18); childhood asthma (OR, 2.92; 95% CI, 1.13-7.36); and sputum production (OR, 2.86; 95% CI, 1.87-4.38). In subjects removed from exposure, severe OA was associated only with sputum production (OR, 3.68; 95% CI, 1.87-7.40); a low education level (OR, 3.41; 95% CI, 1.72-6.80); and obesity (OR, 1.98; 95% CI, 0.97-3.97). CONCLUSIONS: This study indicates that a substantial proportion of subjects with OA experience severe asthma and identifies potentially modifiable risk factors for severe OA that should be targeted to reduce the adverse impacts of the disease.
Assuntos
Asma Ocupacional/epidemiologia , Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Adulto , Asma Ocupacional/tratamento farmacológico , Asma Ocupacional/fisiopatologia , Europa (Continente) , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Razão de Chances , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
BACKGROUND: High-molecular-weight (HMW) proteins and low-molecular-weight (LMW) chemicals can cause occupational asthma (OA) although few studies have thoroughly compared the clinical, physiological, and inflammatory patterns associated with these different types of agents. The aim of this study was to determine whether OA induced by HMW and LMW agents shows distinct phenotypic profiles. METHODS: 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 response to HMW (n = 544) and LMW (n = 635) agents. RESULTS: Multivariate logistic regression analysis showed significant associations between OA caused by HMW agents and work-related rhinitis (OR [95% CI]: 4.79 [3.28-7.12]), conjunctivitis (2.13 [1.52-2.98]), atopy (1.49 [1.09-2.05]), and early asthmatic reactions (2.86 [1.98-4.16]). By contrast, OA due to LMW agents was associated with chest tightness at work (2.22 [1.59-3.03]), daily sputum (1.69 [1.19-2.38]), and late asthmatic reactions (1.52 [1.09-2.08]). Furthermore, OA caused by HMW agents showed a higher risk of airflow limitation (1.76 [1.07-2.91]), whereas OA due to LMW agents exhibited a higher risk of severe exacerbations (1.32 [1.01-1.69]). There were no differences between the two types of agents in the baseline sputum inflammatory profiles, but OA caused by HMW agents showed higher baseline blood eosinophilia and a greater postchallenge increase in fractional nitric oxide. CONCLUSION: This large cohort study describes distinct phenotypic profiles in OA caused by HMW and LMW agents. There is a need to further explore differences in underlying pathophysiological pathways and outcome after environmental interventions.
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Alérgenos/química , Alérgenos/imunologia , Asma Ocupacional/diagnóstico , Asma Ocupacional/etiologia , Exposição Ocupacional/efeitos adversos , Adulto , Asma Ocupacional/sangue , Biomarcadores , Feminino , Humanos , Imunização , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Peso Molecular , Razão de Chances , Testes de Função Respiratória , Estudos RetrospectivosRESUMO
PURPOSE OF REVIEW: Numerous clinically relevant allergenic molecules enhance the performance of specific (s) IgE tests and improve the specificity of allergy diagnosis. This review aimed to summarize our current knowledge of the high-molecular-weight allergens involved in the development of occupational asthma and rhinitis and to critically analyze the contribution of component-resolved diagnosis in the management of these conditions. RECENT FINDINGS: There is a lack of standardization and validation for most available extracts of occupational agents, and assessment of sIgE reactivity to occupational allergen components has been poorly investigated, with the notable exception of natural rubber latex (NRL) and wheat flour. In the case of NRL, the application of recombinant single allergens and amplification of natural extracts with stable recombinant allergens improved the test sensitivity. IgE-sensitization profile in patients with baker's asthma showed great interindividual variation, and extract-based diagnostic is still recommended. For other occupational allergens, it remains necessary to evaluate the relevance of single allergen molecules for the sensitization induced by occupational exposure. Progress has been made to characterize occupational allergens especially NRL and wheat, although there is still an unmet need to increase the knowledge of occupational allergens, to include standardized tools into routine diagnostic, and to evaluate their usefulness in clinical practice.