Effect of environmental pollution on asthma due to soybean /

Abstract

Soybean is one of the most valuable crops in the world, a major source of vegetable protein and oil, but also, a cause of asthma. In cities with ports where soybean is loaded or unloaded, community outbreaks of asthma have been described and attributed to inhalation of soybean dust. Measuring soybean aeroallergens levels with highly sensitive methods is essential in the assessment of health risks due to these airborne substances. Currently, soybean aeroallergens exposure in the environment is monitored using ELISA assays which must be evaluated in a specialized laboratory by skilled personnel. Cost-efficient, less labor-intensive technological procedures for monitoring soy allergens levels can be a very useful tool. Consequently, the development, performance and suitability of a rapid test for the detection of soybean aeroallergens in environmental samples was investigated. The rapid test developed detected a wide range of soybean aeroallergen concentrations with a substantial agreement in visual assay interpretations between independent evaluators, a good concordance with ELISA results, a strong correlation with densitometry results, and adequate sensitivity and specificity. The strip assay developed is rapid, simple, and has considerable potential in the environmental monitoring field for screening soy aeroallergens levels in port cities where allergen measurements are not currently performed. Due to its simplicity, the test will improve the management of soy allergic patients by controlling environmental allergen exposure without the need for apparatus or skilled personnel. Although the understanding of allergic asthma pathogenesis has increased substantially, and the effect of aeroallergen assessment shows to be effective, our current understanding about soybean asthma has some knowledge gaps, as is to know how pollution can interact or modify the effect of soybean allergens. Diesel exhaust particles (DEP) are the solid fraction of the complex mixture of diesel exhaust, and one of the most prevalent anthropogenic pollutants worldwide. Research over recent decades has provided very informative results, and has suggested that DEP can enhance allergen-driven asthmatic immunopathology, but the ability of DEP to do so appears highly dependent on a wide range of variables, and the underlying mechanism remains unclear. The experimental modelling of asthma, particularly the development of murine models, besides being very useful to further investigate the pathogenesis of the disease, can contribute to a deeper understanding of the effects of DEP over asthma. The development of a murine model of combined exposure to soybean and DEP can provide new insights to increase our understanding of the contribution of DEP to asthma development, exacerbation and the mechanisms underlying these processes. This study with the standardization of a novel murine model of asthma and the assessing of the combined effect of soybean aeroallergens and DEP, shows that the continuous administration of soybean allergens at a certain concentration is capable of triggering an asthmatic response. In addition, it also demonstrates that the coexposure to soybean allergens and DEP results in a stronger asthmatic response, increasing airway hyperresponsiveness and pulmonary inflammation even when the concentration of soybean allergen is incapable of promoting an inflammatory response by itself. This mouse model provides evidence that the mechanism underlying soybean asthma is a mixed Th2/Th17 response, and also that DEP is capable of enhancing the allergenic effect of soybean through a Th17-mediated mechanism. These findings suggest that particulate matter monitoring as a surrogate of DEP exposure may be a useful addition to the allergen monitoring in the attempt to prevent new asthma outbreaks.