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Chemical related sensitivity illnesses present new and serious challenges to modern society and the medical community. A large and growing number of patients have developed illnesses related to modern day environmental chemical exposures. The patient tends to have multiple symptoms that are often disabling and are referable to many organ systems, particularly the brain and nervous system, and the immune system. The mechanism of chemical sensitivity is not entirely understood. It has been theorized that small amounts of chemicals disrupt the function of the hypothalamus. Chemical interference with this critical tissue may account for dysfunction of the immune system and many diverse symptoms affecting every part of the body. Chemicals may also destroy or paralyze different enzymes involved in our natural detoxification systems, hence triggering hypersensitivity to minute amounts of chemical exposures. For many years, traditional methods for toxicological assessment have implicated the immune system as a frequent target organ of toxic insult following chronic or sub-chronic exposure to certain chemicals. This awareness of immunotoxicology was stimulated by a comprehensive review by Vos in 1977 in which he provided evidence that the broad spectrum of xenobiotics alter immune responses in laboratory animals and subsequently may affect the health of exposed individuals. Clinical studies in humans exposed to xenobiotics have confirmed the parallelism with immune dysfunction observed in rodents. In both cases, multiple immune dysfunction observed in rodents. These multiple immune derangements including decreased cell medicated immunity, lymphokine production, natural killer cell function and mitogen induced lymphocyte blastogenesis. Impaired suppressor or helper cell generations with increased or decreased helper-suppressor ratios, and increase in antigen reactive Ta1 positive cells have also been reported. Paradoxically, hyperactive B cell function has been the rule, as evidenced by enhanced spontaneous immunoglobulin production, rheumatoid factor, immune complex formation and induction of tissue specific autoantibodies. Therefore, interaction of the immune system with these xenobiotics may result in three principal undesirable effects (Fig.8): |
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