Occupational asthma: current concepts in pathogenesis, diagnosis, and management.
ABSTRACT Occupational asthma (OA) may account for 25% or more of de novo adult asthma. The nomenclature has now better defined categories of OA caused by sensitizing agents and irritants, the latter best typified by the reactive airways dysfunction syndrome. Selecting the most appropriate diagnostic testing and management is driven by assessing whether a sensitizer is involved, and if so, identifying whether the sensitizing agent is a high-molecular-weight agent such as a protein or a low-molecular-weight reactive chemical such as an isocyanate. Increased understanding of the pathogenesis of OA from reactive chemical sensitizers is leading to development of better diagnostic testing and also an understanding of why testing for sensitization to such agents can be problematic. Risk factors for OA including possible genetic factors are being delineated better. Recently published guidelines for the diagnosis and management of occupational asthma are summarized; these reflect an increasingly robust evidence basis for recommendations. The utility of diagnostic tests for OA is being better defined by evidence, including sputum analysis performed in relation to work exposure with suspected sensitizers. Preventive and management approaches are reviewed. Longitudinal studies of patients with OA continue to show that timely removal from exposure leads to the best prognosis.
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ABSTRACT: Background. More than 400 agents have been documented as causing occupational asthma (OA). The list of low-molecular-weight (LMW) agents that have been identified as potential causes of OA is constantly expanding, emphasizing the need to continually update our knowledge by reviewing the literature. Objective. The objective of this paper was to identify all new LMW agents causing occupational asthma reported during the period 2000-2010. Methods. A Medline search was performed using the keywords occupational asthma, new allergens, new causes, and low-molecular-weight agents. Results. We found 39 publications describing 41 new LMW causal agents, which belonged to the following categories: drugs (n = 12), wood dust (n = 11), chemicals (n = 8), metals (n = 4), biocides (n = 3), and miscellaneous (n = 3). The diagnosis of OA was confirmed through SIC for 35 of 41 agents, peak expiratory flow monitoring for three (3) agents, and the clinical history alone for three (3) agents. Immunological tests provided evidence supporting an IgE-mediated mechanism for eight (8) (20%) of the newly described agents. Conclusion. This paper highlights the importance of being alert to the occurrence of new LMW sensitizers, which can elicit OA. The immunological mechanism is explained by a type I hypersensitivity reaction in 20% of all newly described LMW agents.Journal of Allergy 01/2012; 2012:597306.
Article: Environmental isocyanate-induced asthma: morphologic and pathogenetic aspects of an increasing occupational disease.[show abstract] [hide abstract]
ABSTRACT: Occupational diseases affect more and more people every year. According to the International Labour Organization (ILO), in 2000 an estimated amount of at least 160 million people became ill as a result of occupational-related hazards or injuries. Globally, occupational deaths, diseases and injuries account for an estimated loss of 4% of the Gross Domestic Product. Important substances that are related to occupational diseases are isocyanates and their products. These substances, which are used in a lot of different industrial processes, are not only toxic and irritant, but also allergenic. Although the exposure to higher concentrations could be monitored and restricted by technical means, very low concentrations are difficult to monitor and may, over time, lead to allergic reactions in some workers, ending in an occupational disease. In order to prevent the people from sickening, the mechanisms underlying the disease, by patho-physiological and genetical means, have to be known and understood so that high risk groups and early signs in the development of an allergic reaction could be detected before the exposure to isocyanates leads to an occupational disease. Therefore, this paper reviews the so far known facts concerning the patho-physiologic appearance and mechanisms of isocyanate-associated toxic reactions and possible genetic involvement that might trigger the allergic reactions.International Journal of Environmental Research and Public Health 09/2011; 8(9):3672-87. · 1.61 Impact Factor
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ABSTRACT: Asthma and chronic obstructive pulmonary disease (COPD) are the two most prominent chronic inflammatory lung diseases with increasing prevalence. Both diseases are associated with mild or severe remodeling of the airways. In this review, we postulate that the pathologies of asthma and COPD may result from inadequate responses and/or a deregulated balance of a group of cell differentiation regulating factors, the CCAAT/Enhancer Binding Proteins (C/EBPs). In addition, we will argue that the exposure to environmental factors, such as house dust mite and cigarette smoke, changes the response of C/EBPs and are different in diseased cells. These novel insights may lead to a better understanding of the etiology of the diseases and may provide new aspects for therapies.The Open Respiratory Medicine Journal 01/2012; 6:1-13.