Useful biomarkers for assessing the adverse health effects of PCBs in allergic children: pediatric molecular epidemiology.

Mayumi Tsuji

doi:10.1007/s12199-014-0419-1

Abstract

The incidences of childhood allergies have been increasing in recent years in many parts of the world. The development of allergic disorders is attributed to a complex series of interactions between individuals' genetic backgrounds and their immune and psychoneurotic responses to environmental factors. Among the various possible environmental causes of childhood allergies, the early exposure of developing infants to air pollutants and the presence of persistent chemical pollutants such as pesticides have been suggested most frequently. Therefore, it is very important to obtain epidemiological evidence of direct associations between clearly defined adverse health effects and exposure to low levels of pollutants. However, there are no useful biomarkers for assessing such associations. Thus, we planned to establish reliable health-related biomarkers that could be used to investigate these relationships in children. The serum concentrations of several sub-types of polychlorinated biphenyl (PCB) congeners were found to be significantly correlated with interleukin (IL)-8 mRNA expression among asthmatic children. In addition, IL-22 mRNA expression was found to be particularly useful for detecting the effects of environmental pollutants, especially PCB congeners, in a sub-population of vulnerable children who exhibited positive immunoglobulin E (IgE) responses to milk or egg. Furthermore, we detected significant differences in IL-22 mRNA expression between the IgE-negative non-asthmatic subjects and the asthmatic children who exhibited positive IgE reactions toward egg or milk. In conclusion, IL-8 and IL-22 mRNA expressions could be useful biomarkers for detecting sub-populations of children who are particularly vulnerable to the adverse health effects of environmental pollutants, especially PCBs.

Highlights

Allergic diseases, including atopic dermatitis (AD), food allergies, allergic rhinitis, and asthma, are the most common chronic diseases in developed countries and affect up to 20 % of children in industrialized nations [1, 2]
We briefly introduce our latest study, which tested the prediction that in utero polychlorinated biphenyl (PCB) exposure adversely affects placental morphology, potentially leading to placental insufficiency followed by fetal growth restriction [intrauterine growth restriction (IUGR)] and the onset of childhood allergies [20]
When the subjects were divided into two sub-groups based on whether they exhibited positive or negative immunoglobulin E (IgE) reactions to egg, milk, or wheat, as evaluated based on their serum levels of specific IgE, IL-22 expression was found to be significantly correlated with the proximity of the child’s home to major highways among the IgE-positive children, but not among the IgE-negative sub-group, suggesting that the former sub-group represents a susceptible sub-population that is more likely to be adversely affected by the environmental risk factors associated with major highways

Summary

Introduction

Allergic diseases, including atopic dermatitis (AD), food allergies, allergic rhinitis, and asthma, are the most common chronic diseases in developed countries and affect up to 20 % of children in industrialized nations [1, 2]. According to a previous report, asthma is associated with developed countries [3]. The development of allergic disorders is attributed to a series of complex interactions between individuals’ genetic backgrounds and their immune and psychoneurotic responses to environmental factors [4]. The concordance rates of asthma, AD, and bronchial hyperresponsiveness were found to be higher among monozygotic twin pairs than among dizygotic twin pairs [5]. We examined the concordance rates of positive responses to food and indoor allergens between siblings with AD, and the factors associated with the subjects’ responses to such allergens [6]. Only allergen-specific positive responses to oil seeds, i.e., peanuts, sesame seeds, and soybeans, exhibited concordance between siblings. There was no significant correlation in the responses induced by egg during CAP radioallergosorbent tests (CAP-RAST) between sibling pairs the frequency of positive CAP-RAST results was highest for egg Environ Health Prev Med (2015) 20:3–11

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