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Introduction
The Immune System
Assessment of Immunological Integrity
Immune Modulation by Xenobiotics
Halogenated Aromatic Hydrocarbons
Polychlorinated Dibenzodioxins
Polychlorinated Dibenzofurans
Polychlorinated Biphenyls
Polybrominated Biphenyls
Polycyclic Aromatic Hydrocarbons
Pesticides
Organophosphates
Organochlorines
Organotins
Carbamates
Atrazine
Metals
Lead
Arsenic
Mercury
Cadmium
Solvents and Related Chemicals
Mycotoxins
Natural and Synthetic Hormones
Estrogens
Androgens
Glucocorticoids
Therapeutic Agents
Immunosuppressive Agents
AIDS Therapeutics
Biologics
Anti-inflammatory Agents
Drugs of Abuse
Cannabinoids
Opioids
Cocaine
Methamphetamine
Ethanol
Inhaled Substances
Ultraviolet Radiation
Xenobiotic-Induced Hypersensitivity and Autoimmunity
Hypersensitivity
Autoimmunity
Therapeutic Agents
Halothane
Vinyl Chloride
Mercury
Silica
Hexachlorobenzene
New Frontiers and Challenges in Immunotoxicology
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Immunotoxicology can be most simply defined as the study of adverse effects on the immune system resulting from occupational, inadvertent, or therapeutic exposure to drugs, environmental chemicals, and, in some instances, biological materials. Studies in animals and humans have indicated that the immune system is comprised of potential target organs, and that damage to this system can be associated with morbidity and even mortality. Indeed, in some instances, the immune system can be compromised (decreased lymphoid cellularity, alterations in lymphocyte subpopulations, decreased host resistance, and altered specific immune function responses) in the absence of observed toxicity in other organ systems. These studies coupled with tremendous advances made in immunology and molecular biology have led to a steady and exponential growth in our understanding of immunotoxicology during the past 30 years. Recognition by regulatory agencies that the immune system is an important, as well as sensitive, target organ for chemical- and drug-induced toxicity is another indication of the growth of this subdiscipline of toxicology. With the availability of sensitive, reproducible, and predictive tests, it is now apparent that the inclusion of immunotoxicity testing represents a significant adjunct to routine safety evaluations for therapeutic agents, biological agents, and chemicals now in development.
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Understanding the impact of toxic responses on the immune system requires an appreciation of its role, which may be stated succinctly as the preservation of integrity. It is a series of delicately balanced, complex, multicellular, and physiological mechanisms that allow an individual to distinguish foreign material (ie, “nonself”) from “self,” and to neutralize, eliminate, and/or coexist with the foreign matter. Examples of self are all the tissues, organs, and cells of the body. ...