Occupational Sensitization Research Articles

Association of HLA class II alleles with sensitization to cow dander Bos d 2, an important occupational allergen

Allergic sensitization results from a complex interaction between genetic and environmental factors. Earlier studies have shown that highly polymorphic HLA genes are associated with a variety of allergies. Several important respiratory allergens belong to the family of lipocalin proteins. These include occupational sensitizers, such as cow Bos d 2 or rat Rat n 1, and prevalent indoor sensitizers, such as dog Can f 1 or cockroach Bla g 4. HLA associations with sensitization to lipocalin allergens are incompletely known. In the present study we have investigated an association between HLA alleles and sensitization to the major cow allergen Bos d 2. The HLA-DR/DQ genotypes of 40 Bos d 2-sensitized subjects having occupational asthma were determined by polymerase chain reaction (PCR) and the results were compared with the genotypes of 151 unrelated Finnish subjects. The frequencies of HLA class II alleles DRB1*0101, DRB1*0404, DQB1*0302, and DQB1*0501 were significantly higher among Bos d 2-sensitized than among control subjects. In addition, the allergic subjects expressed significantly lower frequencies of HLA-DRB1*0301 and DQB1*0201 alleles than did the control subjects. These data suggest that the HLA class II alleles DRB1*0101, DRB1*0404, DQB1*0302, and DQB1*0501, and the haplotypes that include them, are associated with sensitization to the major cow allergen Bos d 2, whereas HLA-DRB1*0301 and DQB1*0201 are dissociated with it. Amino acid analysis provides a biologically plausible explanation for the HLA associations.

Medium-density fibreboard and occupational asthma. A case series

Medium-density fibreboard (MDF) is a wood composite material, composed primarily of softwood, bonded with a synthetic formaldehyde-based resin. It is increasingly used, as it has various advantages over natural woods. Enquiry of the national reporting scheme data and three case reports were used to further the evidence base linking this exposure to occupational asthma (OA). From 1991 to 2007, 21 cases of occupational sensitization to MDF were reported to the UK voluntary reporting scheme, Surveillance of Work Related Occupational Respiratory Disease (SWORD): 18 reported as occupational asthma (OA) and 3 as occupational rhinitis. All workers were male, with a mean age of 48 years, working in education, furniture manufacturing or joinery among other employments. Whilst reporting scheme data identified relatively small numbers of cases of OA likely to be due to MDF, the evidence base supporting this link is generally lacking. The three cases presented, where OA was attributed to MDF exposure, add to this evidence.

Assessment of caregiver's specific social competencies in dementia care: Development and validation of a self-report instrument

Nursing home staff is faced with various physical and psychic stressors in everyday work life. Social competencies in interacting with dementia patients and their relatives, as well as social support among colleagues, have proven to be important resources for coping with psychic stressors in dementia care. To measure professional caregiver's specific social competencies relevant in dementia care, a short self-report instrument was developed and validated. The “SOKO dementia” was designed containing items regarding social competencies in interaction with dementia patients, colleagues and patients’ relatives. One hundred seventy-two professional caregivers currently employed in a nursing home filled out the “SOKO dementia” as part of an online study. To estimate convergent and discriminatory validity of the instrument, measures of occupational psychic stress, conscientiousness and sensitivity were also assessed. Results of confirmatory factor analysis underline the conceptual adequacy of apportioning social competence in dementia care into specific competencies in interacting with dementia patients, with colleagues and with patients’ relatives. Analyses of reliability as well as convergent and discriminatory validity highlight the good psychometric properties of the “SOKO dementia” questionnaire. Due to its brevity, the “SOKO dementia” can be a useful tool in estimating caregiver's training needs prior to continuous education. The “SOKO dementia” can also be valuable to measure specific effects of training programs focusing on social-communicative skills in dementia care.

Genetic Variability in Susceptibility to Occupational Respiratory Sensitization

Respiratory sensitization can be caused by a variety of substances at workplaces, and the health and economic burden linked to allergic respiratory diseases continues to increase. Although the main factors that affect the onset of the symptoms are the types and intensity of allergen exposure, there is a wide range of interindividual variation in susceptibility to occupational/environmental sensitizers. A number of gene variants have been reported to be associated with various occupational allergic respiratory diseases. Examples of genes include, but are not limited to, genes involved in immune/inflammatory regulation, antioxidant defenses, and fibrotic processes. Most of these variants act in combination with other genes and environmental factors to modify disease progression, severity, or resolution after exposure to allergens. Therefore, understanding the role of genetic variability and the interaction between genetic and environmental/occupational factors provides new insights into disease etiology and may lead to the development of novel preventive and therapeutic strategies. This paper will focus on the current state of knowledge regarding genetic influences on allergic respiratory diseases, with specific emphasis on diisocyanate-induced asthma and chronic beryllium disease.

Occupational sensitization to soy allergens in workers at a processing facility

Exposure to soy antigens has been associated with asthma in community outbreaks and in some workplaces. Recently, 135 soy flake processing workers (SPWs) in a Tennessee facility were evaluated for immune reactivity to soy. Allergic sensitization to soy was common and was five times more prevalent than in health care worker controls (HCWs) with no known soy exposure. To characterize sensitization to soy allergens in SPWs. Sera that were positive to soy ImmunoCAP (n=27) were tested in IgE immunoblots. Wild-type (WT) and transgenic (TG) antigens were sequenced using nanoscale Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry (nanoUPLC MS/MS). IgE reactivity towards 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSP), a protein found in TG soy, was additionally investigated. De-identified sera from 50 HCWs were used as a control. Immunoblotting of WT and TG soy flake extracts revealed IgE against multiple soy antigens with reactivity towards 48, 54, and 62 kDa bands being the most common. The prominent proteins that bound SPW IgE were identified by nanoUPLC MS/MS analysis to be the high molecular weight soybean storage proteins, β-conglycinin (Gly m 5), and Glycinin (Gly m 6). No specific IgE reactivity could be detected to lower molecular weight soy allergens, Gly m 1 and Gly m 2, in soybean hull (SH) extracts. IgE reactivity was comparable between WT and TG extracts; however, IgE antibodies to CP4-EPSP could not be detected. SPWs with specific IgE to soy reacted most commonly with higher molecular weight soybean storage proteins compared with the lower molecular weight SH allergens identified in community asthma studies. IgE reactivity was comparable between WT and TG soy extracts, while no IgE reactivity to CP4-EPSP was observed. High molecular weight soybean storage allergens, Gly m 5 and Gly m 6, may be respiratory sensitizers in occupational exposed SPWs.

Lupin allergy: a hidden killer at home, a menace at work; occupational disease due to lupin allergy

The products of the flowering plant, lupin, are increasingly used as a human food product, particularly in baking. Occupational sensitization to lupin with occupational rhinitis, conjunctivitis and asthma was first described in 2001, and confirmed in a larger cross-sectional study in a food processing company in 2006. Sensitization by inhalation may result in occupational asthma, work-exacerbated asthma, occupational rhinitis and conjunctivitis. The incidence of occupational sensitization may be as high as 29%. The relationship with exposure intensity is as yet unclear, and requires further clarification. Although there is little information from long-term studies, these diseases are likely to improve after cessation of exposure. Cross-sensitization to other legumes, particularly peanuts, has been shown by skin prick testing, with potential for serious anaphylactic reactions. This review summarizes the available literature on occupational sensitization to lupin products. It is one of two reviews, one covering the problem of lupin allergy in the home, while the present article deals with lupin sensitization in the workplace. Increased awareness is needed of this occupational hazard to avoid future cases of occupational disease and their accompanying morbidity and potential mortality.

Formaldehyde‐releasers: relationship to formaldehyde contact allergy. Formaldehyde‐releasers in clothes: durable press chemical finishes. Part 1

This is one of a series of review articles on formaldehyde-releasers and their relationship to formaldehyde contact allergy and in this paper formaldehyde-releasers used as durable press chemical finishes (DPCF) in textiles are discussed. The literature on allergy to DPCF since 1980 is presented in two parts. Part 1 (this article) presents a short historical overview of the problems with formaldehyde in clothes and discusses the chemistry of durable press chemical finishes, legislation in various countries, and studies on the amount of formaldehyde present in clothes. In addition, the DPCF that have caused contact allergy are presented with CAS, synonyms, molecular formula, chemical structure, applications, and patch test studies. In the forthcoming part 2, the frequency of sensitization to DPCF, occupational contact sensitization, relevance of patch test reactions, and relationship to formaldehyde contact allergy will be reviewed, followed by a discussion of both parts of the article together.

Occupational sensitization from theTradescantia albifloracultivar ‘Pink Joy’

Occupational sensitization from the<i>Tradescantia albiflora</i>cultivar ‘Pink Joy’

Interleukin-1β and surface marker expression changes induced by tetrachloroplatinate in human monocyte-derived dendritic cells

Background and aim: Platinum salts, known occupational respiratory sensitizers, may also induce contact hypersensitivity in animal models. The aim of this study was to determine the effect of potassium tetrachloroplatinate (TCPP) on in vitro cultured human monocyte-derived dendritic cells (MoDCs) and to compare it with a response to nickel sulfate (NiSO4). The expression of CD54, CD86, and HLA-DR surface antigens as well as IL-1β transcription was investigated.Conclusions: MoDCs populations generated from three healthy volunteers displayed the phenotype responsive to NiSO4 and non-responsive to sodium dodecyl sulfate (SDS). Clear up-regulation of IL-1β mRNA as well as CD54, CD86 and HLA-DR expression in response to NiSO4 (250 μM) was detected after 48 hrs of exposure. No up-regulation of evaluated surface antigens was observed following the treatment with SDS (150 μM). TCPP (150 μM) similarly to NiSO4 induced up-regulation of IL-1β mRNA, CD54, CD86, but not HLA-DR expression. The response to TCPP showed less inter-individual variability, however it was weaker in comparison to the response to NiSO4. The results suggest that platinum salts can induce in MoDCs phenotypical changes characteristic for skin sensitizers.

Dynamics in cytokine responses during the development of occupational sensitization to rats

Occupational allergy forms an attractive model to study the development of allergic responses, as in some occupations it has a high incidence and develops quickly. In a cohort of starting laboratory animal workers, we previously found 20% sensitization to animal allergens within 2 years. We compared cellular responses of incident laboratory animal workers who developed rat-specific sensitization (cases, n = 18) during 2 years of follow-up to control animal workers matched for atopic status but without sensitization after follow-up (controls, n = 18). Practically, this is a case-control study, nested within the cohort. Rat-specific IgE antibodies were measured in sera, and allergen-specific and nonspecific cytokine responses were measured in whole blood and in isolated peripheral blood mononuclear cells. Self-reported allergic symptoms were related to the presence of rat-specific IgE (P ≤ 0.01). Cases developed a rat allergen-specific interleukin (IL)-4 response during sensitization, while controls did not show an increased IL-4 response (at visit D: 33 vs 5 IL-4 producing cells/10(6) cells, P < 0.001). The IL-4 response was related to the levels of rat-specific IgE in cases (visit D: rho = 0.706, P < 0.001). By contrast, allergen-specific IL-10 and interferon γ (IFNγ) responses as well as nonspecific cytokine responses were comparable between cases and controls. This study is the first to show the development of an allergen-specific IL-4 response in adult human subjects during allergen-specific sensitization. This IL-4 response was quantitatively associated with the development of the specific IgE antibodies. Allergen-specific or nonspecific IL-10 and IFNγ responses showed no protective effect on the development of allergic sensitization.

Sources of sensitization, cross-reactions, and occupational sensitization to topical anaesthetics among general dermatology patients

Sources of sensitization, cross-reactions, and occupational sensitization to topical anaesthetics among general dermatology patients

Parental occupation is a risk factor for childhood wheeze and asthma

The present birth cohort study investigated whether or not childhood wheeze and asthma are associated with parental exposure to occupational sensitisers that cause asthma. Parental occupation, from the Avon Longitudinal Study of Parents and Children (ALSPAC), was related to wheeze, asthma, ventilatory function, airway responsiveness and atopic sensitisation in children aged 0-102 months. Occupation was recorded for 11,193 mothers and 9,473 fathers antenatally, and for 4,631 mothers and 5,315 fathers post-natally. Childhood respiratory outcomes were not associated with parental occupational exposure to diisocyanates, glues/resins, dyes, animal dust, solder, enzymes and wood dust. Maternal post-natal occupational exposure to latex and/or biocides/fungicides increased the likelihood of childhood wheeze and asthma. High levels of latex or biocide/fungicide exposure were associated with an OR (95% CI) of 1.26 (1.07-1.50) and 1.22 (1.02-2.05), respectively, for wheezing up to 81 months. Combined maternal latex and biocide/fungicide exposure increased the likelihood of childhood wheeze (1.22 (1.03-1.43)) and asthma. High paternal occupational flour dust exposure was associated with an increased likelihood of wheeze after 30 months (2.31 (1.05-5.10)) and asthma by 91 months (3.23 (1.34-7.79)). Maternal occupational exposure to latex and/or biocides and paternal exposure to flour dust increases the risk of childhood asthma. Further studies in this area are justified.

Interleukin-1β and surface marker expression changes induced by tetrachloroplatinate in human monocyte-derived dendritic cells

Platinum salts, known occupational respiratory sensitizers, may also induce contact hypersensitivity in animal models. The aim of this study was to determine the effect of potassium tetrachloroplatinate (TCPP) on in vitro cultured human monocyte-derived dendritic cells (MoDCs) and to compare it with a response to nickel sulfate (NiSO4). The expression of CD54, CD86, and HLA-DR surface antigens as well as IL-1beta transcription was investigated. MoDCs populations generated from three healthy volunteers displayed the phenotype responsive to NiSO4 and non-responsive to sodium dodecyl sulfate (SDS). Clear up-regulation of IL-1beta mRNA as well as CD54, CD86 and HLA-DR expression in response to NiSO4 (250 microM) was detected after 48 hrs of exposure. No up-regulation of evaluated surface antigens was observed following the treatment with SDS (150 microM). TCPP (150 microM) similarly to NiSO4 induced up-regulation of IL-1beta mRNA, CD54, CD86, but not HLA-DR expression. The response to TCPP showed less inter-individual variability, however it was weaker in comparison to the response to NiSO4. The results suggest that platinum salts can induce in MoDCs phenotypical changes characteristic for skin sensitizers.

Occupational exposure and sensitization to fungi among museum workers

Museum employees are exposed to fungi and storage mites in the workplace. To evaluate the prevalence and risk factors of sensitization to moulds, as well as clinical symptoms associated with allergy in museum workers. A total of 103 employees of the Polish National Museum (NM) in Warsaw, potentially exposed to fungi during their work, were assessed using a questionnaire and skin prick tests to common allergens and fungal extracts. The level of total and serum-specific IgE to moulds was evaluated, and spirometry was performed in all subjects. Mycological analysis of the workplace was also performed. Penicillium, Aspergillus, Cladosporium, Alternaria, Trichoderma, Acremonium and Paecilomyces were the most frequent species isolated from investigated exhibits of NM. Thirty per cent of museum employees were sensitized to at least one of the fungal allergens. Logistic regression analysis revealed that duration of occupational exposure lasting >5 years, family history of atopy, presence of a cat at home, sinusitis, allergic rhinitis and a history of frequent respiratory infections were risk factors for the development of sensitization to fungi in this working group. This study suggests an important role of fungi as occupational allergens for museum workers. The prevalence of allergic symptoms among employees of NM was relatively high. Further studies are necessary to elucidate the importance of particular fungal species in the development of occupational allergy.

Sources of sensitization, cross‐reactions, and occupational sensitization to topical anaesthetics among general dermatology patients

Contact sensitization to local anaesthetics is often from topical medicaments. Occupational sensitization to topical anaesthetics may occur in certain occupations. The aim of the study was to analyse the occurrence of contact sensitization to topical anaesthetics in general dermatology patients. Patch testing with topical anaesthetics was carried out in 620 patients. Possible sources of sensitization and the clinical histories of the patients are analysed. Positive patch test reactions to one or more topical anaesthetics were seen in 25/620 patients. Dibucaine reactions were most common (20/25), and lidocaine sensitization was seen in two patients. Six patients had reactions to ester-type and/or amide-type anaesthetics concurrently. Local preparations for perianal conditions were the most common sensitizers. One patient had developed occupational sensitization to procaine with multiple cross-reactions and with concurrent penicillin sensitization from procaine penicillin. Dibucaine-containing perianal medicaments are the major source of contact sensitization to topical anaesthetics. Although sensitization to multiple anaesthetics can be seen, cross-reactions are possible. Contact sensitization to lidocaine is not common, and possible cross-reactions should be determined when reactions to lidocaine are seen. Occupational procaine sensitization from veterinary medicaments is a risk among animal workers.

Associations between pre-employment immunologic and airway mucosal factors and the development of occupational allergy

Sensitization to occupational allergens is frequently found in laboratory animal workers (LAWs) and can cause serious health problems. Atopy is a major risk factor for sensitization, but it is considered insufficient to advise against working with animals. We investigated whether immunologic measures, including serology and cytokine production profiles of blood cells, and parameters for airway inflammation are associated with the development of occupational sensitization. In a prospective cohort study 110 starting LAWs were followed for 2 years. At inclusion, results of health questionnaires, skin test results, lung function measures, methacholine threshold levels, and nasal lavage fluid were obtained. Blood was taken for measuring total IgE and allergen-specific IgE antibodies. Cytokine production profiles were measured in whole blood. Twenty-two new cases of sensitization were identified during follow-up. In multivariate logistic regression analysis a model including atopy and total IgE level predicted sensitization best. This was corroborated in a separate validation cohort. Parameters for airway inflammation or cytokine production profiles did not further contribute to the prediction of sensitization. Based on these results, pre-employment counseling aimed at applicant LAWs with atopy and a total IgE level of greater than 100 IU/mL might be able to reduce occupational sensitization by up to 45% to 50% with less than 10% false-positive predictions. The combination of atopy and total IgE level offered the best model to predict development of occupational sensitization. Other immunologic parameters and parameters of airway inflammation did not contribute significantly.

Occupational rhinitis and occupational asthma; one airway two diseases?

The concept of 'one airway, one disease' refers to the frequent comorbidity of asthma and rhinitis. However, only limited research has been done on this association for the diverse range of occupational respiratory sensitisers. The relative frequency of rhinitis was determined for the 15 respiratory sensitisers reported to cause at least 10 cases of rhinitis or asthma to The Health and Occupation Reporting (THOR) network between 1997 and 2006. Of 1408 cases, 1190 were sole diagnoses of asthma, 138 sole diagnoses of rhinitis and in 80 cases asthma coexisted with rhinitis. The six sensitisers for which rhinitis featured in over 15% of cases were all particulates and known to cause release of mast cell mediators, either directly or through IgE antibodies. Four of the other nine sensitisers often exist as vapours and only two have been consistently associated with IgE-mediated disease mechanisms. Particle size did not appear to correlate with the relative frequency of rhinitis. Despite its limitations this study would support the hypothesis that there are at least two mechanistic categories of respiratory sensitisation with rhinitis being relatively more common where the mechanism is IgE-mediated. Particulate nature may be another important factor to consider in future studies.

Comparative airway response to high- versus low-molecular weight agents in occupational asthma

Airway responses to occupational agents in sensitised workers may vary clinically and physiologically. The patterns of change in airway responsiveness, type of response and fall in expiratory flows following laboratory exposure to high- or low-molecular weight agents (HMW and LMW agents, respectively) were compared in sensitised workers. Data on workers who underwent specific inhalation challenges with occupational sensitisers (117 exposed to HMW agents and 130 to LMW agents) were collected from their medical charts. Maximum falls in forced expiratory volume in one second (FEV(1)) were of similar magnitude for both types of agents. Compared with HMW agents, LMW agents induced more frequently late or dual responses and higher increases in airway responsiveness. After exposure to HMW agents, there was a mean+/-sd reduction in doubling concentrations of methacholine of 0.5+/-1.7 for early responses, compared with 2.8+/-1.2 and 1.4+/-2.0 for late and dual responses, respectively. Isolated early responses were more frequently found in females, smokers, workers with a higher % predicted FEV(1) and higher provocation concentration causing a 20% fall in FEV(1), and in those with longer asthma duration. Workers' characteristics, as well as the type of agent they are sensitised to, may help to predict the type of response after specific inhalation challenge.

Risks for the development of outcomes related to occupational allergies: an application of the asthma-specific job exposure matrix compared with self-reports and investigator scores on job-training-related exposure

Background and aim:Risks for development of occupational sensitisation, bronchial hyper-responsiveness, rhinoconjunctival and chest symptoms at work associated with continued exposure to high molecular weight (HMW) allergens were estimated with three...

Which tools best predict the incidence of work-related sensitisation and symptoms

Background/aim: This study used information from the questionnaire alone or in conjunction with clinical tests, such as skin-prick testing (SPT) and bronchial responsiveness (BR) testing at entry, to develop models...