Immunological alterations and chemical exposure.

The complex nature of the immune system with its multiple humoral and cellular components makes it an easy target for many drugs and chemicals. Immunotoxicology is defined as an adverse response of the immune system to a chemical or drug which may result in disease such as autoimmunity, immune suppression, allergy or other hypersensitivity states. Occasionally, immune enhancement is the end result. Because many of the immune system's cellular and humoral components can be isolated and studied in vitro, assays have been developed to study the immunotoxic effects of chemicals. Further refinement of these in vitro studies is required along with clinical investigations into the effects of chemicals on the immune system of humans. Extrapolating from the animal data to human effects has proven to be unsuccessful in many circumstances. Further definition and study of immunotoxic responses as contrasted with normal immune responses to neo-antigens are required to investigate actual disease causation.