Xenobiotic-induced Immune Alterations: Implications in Health and Disease

Immune function may be significantly altered following occupational, inadvertent or therapeutic exposure to chemically diverse xenobiotics. The environmental chemicals like pesticides, halogenated hydrocarbons, polychlorinated dibenzofurans, organic solvents, asbestos, silica, heavy metals etc. may interact with both cellular and humoral components of the immune system which can result in altered immune status that in turn may lead to decreased resistance to infection, certain forms of neoplasia or in some cases exacerbate allergy or autoimmunity. Recent advances in pharmacogenomics and toxicogenomics have contributed a lot to delineate the mechanism of interaction of xenobiotics with the biological system at the cellular and molecular level. However, detection of immune changes on exposure to immunotoxic agents is highly complex, especially in humans due to several confounding factors like age, sex, race gender, co- existence of disease, food habits, smoking etc. Thus, establishing a quantitative relationship between immunotoxicological data and risk assessment, following xenobiotic exposure is still a challenge. The present article reviews the immune alterations caused by exposure to variety of xenobiotics, and their implications in health and disease.