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Doyen V, Gautrin D, Vandenplas O, Malo JL. Comparison of high- and low-molecular-weight sensitizing agents causing occupational asthma: an evidence-based insight. Expert Rev Clin Immunol 2024; 20:635-653. [PMID: 38235552 DOI: 10.1080/1744666x.2024.2306885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 01/15/2024] [Indexed: 01/19/2024]
Abstract
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.
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Affiliation(s)
- Virginie Doyen
- Department of Chest Medicine, Centre Hospitalier Universitaire UCL Namur, Université Catholique de Louvain, Yvoir, Belgium
| | - Denyse Gautrin
- Université de Montréal and Hôpital du Sacré-Cœur de Montréal, Montréal, Canada
| | - Olivier Vandenplas
- Department of Chest Medicine, Centre Hospitalier Universitaire UCL Namur, Université Catholique de Louvain, Yvoir, Belgium
| | - Jean-Luc Malo
- Université de Montréal and Hôpital du Sacré-Cœur de Montréal, Montréal, Canada
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Cochrane SA, Arts JHE, Ehnes C, Hindle S, Hollnagel HM, Poole A, Suto H, Kimber I. Thresholds in chemical respiratory sensitisation. Toxicology 2015; 333:179-194. [PMID: 25963507 DOI: 10.1016/j.tox.2015.04.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/16/2015] [Accepted: 04/16/2015] [Indexed: 12/26/2022]
Abstract
There is a continuing interest in determining whether it is possible to identify thresholds for chemical allergy. Here allergic sensitisation of the respiratory tract by chemicals is considered in this context. This is an important occupational health problem, being associated with rhinitis and asthma, and in addition provides toxicologists and risk assessors with a number of challenges. In common with all forms of allergic disease chemical respiratory allergy develops in two phases. In the first (induction) phase exposure to a chemical allergen (by an appropriate route of exposure) causes immunological priming and sensitisation of the respiratory tract. The second (elicitation) phase is triggered if a sensitised subject is exposed subsequently to the same chemical allergen via inhalation. A secondary immune response will be provoked in the respiratory tract resulting in inflammation and the signs and symptoms of a respiratory hypersensitivity reaction. In this article attention has focused on the identification of threshold values during the acquisition of sensitisation. Current mechanistic understanding of allergy is such that it can be assumed that the development of sensitisation (and also the elicitation of an allergic reaction) is a threshold phenomenon; there will be levels of exposure below which sensitisation will not be acquired. That is, all immune responses, including allergic sensitisation, have threshold requirement for the availability of antigen/allergen, below which a response will fail to develop. The issue addressed here is whether there are methods available or clinical/epidemiological data that permit the identification of such thresholds. This document reviews briefly relevant human studies of occupational asthma, and experimental models that have been developed (or are being developed) for the identification and characterisation of chemical respiratory allergens. The main conclusion drawn is that although there is evidence that the acquisition of sensitisation to chemical respiratory allergens is a dose-related phenomenon, and that thresholds exist, it is frequently difficult to define accurate numerical values for threshold exposure levels. Nevertheless, based on occupational exposure data it may sometimes be possible to derive levels of exposure in the workplace, which are safe. An additional observation is the lack currently of suitable experimental methods for both routine hazard characterisation and the measurement of thresholds, and that such methods are still some way off. Given the current trajectory of toxicology, and the move towards the use of non-animal in vitro and/or in silico) methods, there is a need to consider the development of alternative approaches for the identification and characterisation of respiratory sensitisation hazards, and for risk assessment.
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Affiliation(s)
- Stella A Cochrane
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, Mk44 1LQ, UK.
| | | | - Colin Ehnes
- BASF SE, GUP/PB - Z470, 67056 Ludwigshafen, Germany
| | - Stuart Hindle
- Dow Europe GmbH, Bachtobelstrasse 3, CH-8810 Horgen, Switzerland
| | - Heli M Hollnagel
- Dow Europe GmbH, Bachtobelstrasse 3, CH-8810 Horgen, Switzerland
| | - Alan Poole
- ECETOC, Avenue Van Nieuwenhuyse 2, Box 8, B-1160 Bruxelles, Belgium
| | - Hidenori Suto
- Sumitomo Chemical Co. Ltd. Environmental Health Science Laboratory, 3-1-98 Kasugade-Naka, Konohana-Ku, Osaka 554-8558, Japan
| | - Ian Kimber
- University of Manchester, Faculty of Life Sciences, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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Harris-Roberts J, Robinson E, Fishwick D, Fourie A, Rees D, Spies A, Curran A, Sen D, Barber C. Sensitization and symptoms associated with soybean exposure in processing plants in South Africa. Am J Ind Med 2012; 55:458-64. [PMID: 22314699 DOI: 10.1002/ajim.22009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2011] [Indexed: 11/11/2022]
Abstract
BACKGROUND Following the results of a previous study that highlighted the potential for significant levels of dust exposure in South African soybean processing plants, a clinical investigation was undertaken to study the respiratory health of workers in this industry. METHODS Workers from three soybean-processing plants were studied with a respiratory questionnaire and estimation of atopy and specific soybean IgE. RESULTS A total of 144 of the 181 (79.6% participation rate) plant employees completed the questionnaire and 136 (75.1%) gave blood samples for analysis of specific IgE. There was a significant association between work-related chest tightness (OR 4.0 [95% CI 1.3-12.6]), work-related nasal symptoms (OR 4.3 [95% CI 1.3-14.6]) and cough or chest tightness after handling soybean (OR 3.6 [95% CI 1.1-11.6]) and soybean sensitization. There was a significant association between current exposure to dust during soybean off-loading and "flu-like" illness (OR 2.7 [95% CI 1.0-7.2]), and cough or chest tightness after such work (OR 7.4 [95% CI 2.4-23.6]). The strongest predictor of work related nasal symptoms was sensitization to soybean, the latter strongly predicted by the presence of atopy (OR 34.7 [95% CI 6.6-182.5]). CONCLUSIONS Exposure and sensitization to soybean were associated with the presence of work related symptoms, including flu-like symptoms, cough, chest tightness, and nasal symptoms. The aetiology of these symptoms and more particularly the best intervention strategies require more detailed investigation.
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Jeppsson MC, Lindh CH, Kristiansson MH, Nielsen J, Jönsson BAG. Methylhexahydrophthalic anhydride adducted albumin tryptic peptides in nasal lavage fluid. Inhal Toxicol 2009; 21:1013-20. [PMID: 19772480 DOI: 10.1080/08958370802715997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Methylhexahydrophthalic anhydride (MHHPA) is a reactive, low molecular weight chemical used in products such as plastics, paints, and electronic components. Exposure to MHHPA may lead to work-related airway diseases such as rhinitis, conjunctivitis, and asthma. Twelve subjects employed at a plant manufacturing electrical capacitors using MHHPA were included in this study. Nasal lavages were collected from subjects before work Monday morning and after work Tuesday afternoon. The levels of MHHPA adducted to serum albumin were analyzed with a straightforward work-up method. The samples were trypsinated before being analyzed with a liquid chromatography-triple quadrupole mass spectrometer. The mass spectrometer was run using selected reaction monitoring for six adducted peptides. Also, some biomarkers of effect (albumin, total protein, eosinophil cationic protein, and tryptase) were analyzed in nasal lavages. Furthermore, the metabolite MHHP acid in urine after work on Tuesday was analyzed by gas chromatography-mass spectrometry. Symptoms from the airways and the eyes and sensitization were registered. The main result of this study is that protein adducts can be analyzed in vivo after low occupational exposures to MHHPA. The results also show a correlation between adducted peptides and albumin in nasal lavage. Furthermore, there may be a difference in the potential to induce hyperresponsiveness between adducts bound to different amino acids.
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Affiliation(s)
- Marina C Jeppsson
- Department of Occupational and Environmental Medicine, Institute of Laboratory Medicine, University Hospital, Lund, Sweden.
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Helaskoski E, Kuuliala O, Aalto-Korte K. Occupational contact urticaria caused by cyclic acid anhydrides. Contact Dermatitis 2009; 60:214-21. [DOI: 10.1111/j.1600-0536.2009.01526.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Arts JHE, Mommers C, de Heer C. Dose-Response Relationships and Threshold Levels in Skin and Respiratory Allergy. Crit Rev Toxicol 2008; 36:219-51. [PMID: 16686423 DOI: 10.1080/10408440500534149] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A literature study was performed to evaluate dose-response relationships and no-effect levels for sensitization and elicitation in skin- and respiratory allergy. With respect to the skin, dose-response relationships and no-effect levels were found for both intradermal and topical induction, as well as for intradermal and topical elicitation of allergenic responses in epidemiological, clinical, and animal studies. Skin damage or irritation may result in a significant reduction of the no-effect level for a specific compound. With respect to the respiratory tract, dose-response relationships and no-effect levels for induction were found in several human as well as animal studies. Although dose-response relationships for elicitation were found in some epidemiological studies, concentration-response relationships were present only in a limited number of animal studies. Reported results suggest that especially relatively high peak concentrations can induce sensitization, and that prevention of such concentrations will prevent workers from developing respiratory allergy. Moreover, induction of skin sensitization may result in subsequent heightened respiratory responsiveness following inhalation exposure. The threshold concentration for the elicitation of allergic airway reactions in sensitized subjects is generally lower than the threshold to induce sensitization. Therefore, it is important to consider the low threshold levels for elicitation for recommendation of health-based occupational exposure limits, and to avoid high peak concentrations. Notwithstanding the observation of dose-response relationships and no-effect levels, due to a number of uncertainties, no definite conclusions can be drawn about absolute threshold values for allergens with respect to sensitization of and elicitation reactions in the skin and respiratory tract. Most predictive tests are generally meant to detect the potential of a chemical to induce skin and/or respiratory allergy at relatively high doses. Consequently, these tests do not provide information of dose-response relationships at lower doses such as found in, for example, occupational situations. In addition, the observed dose-response relationships and threshold values have been obtained by a wide variety of test methods using different techniques, such as intradermal exposure versus topical or inhalation exposure at the workplace, or using different endpoints, which all appear important for the outcome of the test. Therefore, especially with regard to respiratory allergy, standardized and validated dose-response test methods are urgently required in order to be able to recommend safe exposure levels for allergens at the workplace.
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Nielsen J, Welinder H, Bensryd I, Rylander L, Skerfving S. Ocular and airway symptoms related to organic acid anhydride exposure--a prospective study. Allergy 2006; 61:743-9. [PMID: 16677245 DOI: 10.1111/j.1398-9995.2006.01028.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Organic acid anhydrides (OAA) are used as hardeners in epoxy resin systems. They are powerful sensitizers giving frequent rhinitis and asthma in exposed workers. Incidence of symptoms is unknown. Here we present the first prospective study on the associations between OAA exposure, symptoms, and effects of confounding factors. METHODS All new employees in three plants handling OAA were followed for up to 8.5 years. Before the employment, a questionnaire reporting about symptoms of eyes and airways, smoking habits, and atopy was answered. The subjects were asked at regular medical examinations about work tasks and work-related symptoms. Serum was analysed for specific OAA antibodies. RESULTS Mean exposures varied between 6 and 39 microg/m3. The incidence for work-related symptoms of the eyes, nose, pharynx, and lower airways was 91, 64, 46, and 31 per 1000 years of exposure, respectively. Symptoms were found frequently, even at mean exposure level at <10 microg/m3. Smoking and atopy increased the risk of symptoms. Immunoglobulin (Ig)E sensitized workers had a significant increased risk for symptoms of the eyes and pharynx and for running nose/sneezing. CONCLUSIONS Organic acid anhydrides exposure is associated with frequent ocular and airway symptoms even at mean exposure levels at <10 microg/m3. There is an important need for establishment of an occupational threshold limit. A limit value of below 5 microg/m3 is proposed.
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Affiliation(s)
- J Nielsen
- Department of Occupational and Environmental Medicine, University Hospital Lund, Lund, Sweden
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Nielsen GD, Olsen O, Larsen ST, Løvik M, Poulsen LK, Glue C, Brandorff NP, Nielsen PJ. IgE-mediated sensitisation, rhinitis and asthma from occupational exposures. Smoking as a model for airborne adjuvants? Toxicology 2005; 216:87-105. [PMID: 16139408 DOI: 10.1016/j.tox.2005.07.022] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 07/22/2005] [Accepted: 07/28/2005] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Airborne pollutants with adjuvant effect, called airborne adjuvants, may promote IgE-sensitisation and development of allergic airway diseases. Smoking and occupational allergen exposures were reviewed to establish a general and verified framework for hazard identification and risk assessment of adjuvant effects of airborne pollutions. METHODS The relative risks and the attributable risks of adjuvant effect of smoking were determined for co-exposures with green coffee and castor beans, ispaghula, senna, psyllium, flour and grain dust, latex, laboratory animals, seafood, enzymes, platinum salts, organic anhydrides, or reactive dyes. RESULTS Adjuvant effects of smoking depended on the types of allergen, but not on whether sensitisation or allergy was promoted by atopy-the hereditarily increased ability to increase IgE formation. CONCLUSION Promotion of IgE sensitisation in humans and in animals may serve for hazard identification of adjuvant effects. Risk assessment has been based mainly on epidemiological studies, which are sensitive to confounding factors. This highlights the need to develop appropriate animal models for risk assessment.
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Affiliation(s)
- Gunnar D Nielsen
- National Institute of Occupational Health Denmark, Lersø Parkallé 105, DK-2100 Copenhagen, Denmark.
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Abstract
Substantial epidemiologic and clinical evidence indicates that agents inhaled at work can induce asthma. In industrialized countries, occupational factors have been implicated in 9 to 15% of all cases of adult asthma. Work-related asthma includes (1) immunologic occupational asthma (OA), characterized by a latency period before the onset of symptoms; (2) nonimmunologic OA, which occurs after single or multiple exposures to high concentrations of irritant materials; (3) work-aggravated asthma, which is preexisting or concurrent asthma exacerbated by workplace exposures; and (4) variant syndromes. Assessment of the work environment has improved, making it possible to measure concentrations of several high- and low-molecular-weight agents in the workplace. The identification of host factors, polymorphisms, and candidate genes associated with OA is in progress and may improve our understanding of mechanisms involved in OA. A reliable diagnosis of OA should be confirmed by objective testing early after its onset. Removal of the worker from exposure to the causal agent and treatment with inhaled glucocorticoids lead to a better outcome. Finally, strategies for preventing OA should be implemented and their cost-effectiveness examined.
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Affiliation(s)
- Cristina E Mapp
- Section of Hygiene and Occupational Medicine, Department of Clinical and Experimental Medicine, University of Ferrara, Italy.
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Pfäffli P, Hämeilä M, Riala R, Tornaeus J, Wirmoila R. Exposure to methylhexahydrophthalic anhydride (MHHPA) in two workplaces of the electric industry. ACTA ACUST UNITED AC 2004; 6:295-9. [PMID: 15054537 DOI: 10.1039/b310964j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Methylhexahydrophthalic anhydride (MHHPA) is a hardener for hot-cured epoxy resins employed as insulators in the electric industry. MHHPA has only been measured as an ingredient with other alicyclic anhydrides, albeit there are also large processes which use only MHHPA. We collected MHHPA vapour in a set of devices: Teflon filter, glass spiral, TenaxTA tube connected consecutively together. Elution was performed with a solvent mixture of methyl-tert-butyl ether (70%), acetonitrile (30%), and acetic anhydride (0.5%). By capillary GC-ECD, the regression was linear (0.9994) in the practical low concentration range of 0.04-1 microg ml(-1) being equal to 0.001-0.035 mg m(-3) in 30 l of air. The exposure was measured in two factories manufacturing electric appliances. The assembled objects were first impregnated with a liquid epoxy/hardener mixture, and then the resin hardened at elevated temperature. In condenser manufacturing, the operators' 8 h exposure ranged from 0.068 to 0.118 mg m(-3), and the short-term exposure was during operation at ovens mean 1.90 mg m(-3). The impregnation of coiled resistors and transfer of them to ovens caused the worst exposures, short-term mean 3.846 mg m(-3) and long-term mean 2.191 mg m(-3). During the 'baking', the ovens were closed and evacuated, but when the hot objects were moved out of the ovens, they continued during chilling to emit MHHPA, mean 0.366 mg m(-3). In the adjacent areas, assembling, control rooms, offices, the exposure was still significant, 0.017-0.043 mg m(3), due to leaks from the high exposure areas. Mechanical general ventilation and local exhausts were functioning. Respirators were available for short supervising of the hot equipment.
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Affiliation(s)
- Pirkko Pfäffli
- Finnish Institute of Occupational Health, Department of Industrial Hygiene and Toxicology, Topeliuksenkatu 41 a A, FIN-00250 Helsinki, Finland.
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Matsumoto N, Yokota K, Johyama Y, Takakura T. [The working environment control of anhydride hardeners from an epoxy resin system]. SANGYO EISEIGAKU ZASSHI = JOURNAL OF OCCUPATIONAL HEALTH 2003; 45:133-8. [PMID: 12968499 DOI: 10.1539/sangyoeisei.45.133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
Epoxy resins are widely used in adhesives, coatings, materials for molds and composites, and encapsulation. Acid anhydrides such as methyltetrahydrophthalic anhydride are being used as curing agents for epoxy resins. The anhydride hardeners are well-known industrial inhalant allergens, inducing predominantly type I allergies. In the electronic components industry, these substances have been consumed in large quantities. Therefore, safe use in the industry demands control of the levels of exposure causing allergic diseases in the workshop. We conducted a prospective survey of two electronics plants to clarify how to control the atmospheric level of the anhydrides in the work environment. Measurements of the levels of the anhydrides in air started according to the Working Environment Measurement Standards (Ministry of Labour Notification No. 46, 1976) in April 2000, along with improvements in the work environment. A value of 40 micrograms/m3 was adopted as the administrative control level to judge the propriety of the working environment control. A total of 2 unit work areas in both plants belonged to Control Class III. The exposure originated from manual loading, casting, uncured hot resins, and leaks in an impregnating-machine or curing ovens. In order to achieve the working environment control, complete enclosure of the source, installation of local exhaust ventilation, and improvement or maintenance of the local exhaust ventilation system were performed on the basis of the results of the working environment measurement, with the result that the work environment was improved (Control Class I). It became evident that these measures were effective just like other noxious substances.
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Affiliation(s)
- Naomi Matsumoto
- Matsushita Science Center of Industrial Hygiene, 7-6 Tonoshima-cho, Kadoma, Osaka 571-0045, Japan
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Abstract
The acid anhydrides have been signal occupational agents for study because of their inherent and complex biological activity and the wide range of associated occupational airway disease that is manifest in exposed workers in a variety of occupational settings. This year in review has shed light on many of the complexities of anhydride exposure, biologic reactivity and airway disease.
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Affiliation(s)
- C Raymond Zeiss
- Northwestern University Medical School, Chicago, Illinois 60611, USA.
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