Identification of immunotoxic effects of chemicals and assessment of their relevance to XXXX .

@entity1 @entity137 @entity5 @entity566 @entity565 @entity5526 @entity281 @entity56 @entity792
Immunotoxicity is defined as the adverse effects of foreign substances (xenobiotics) on the immune system. Two types of effects are possible: immunosuppression (which may result in an increased susceptibility to @entity281 or to the development of @entity5 ) and immunopotentiation (which may manifest as an @entity566 or as @entity792 ). There is, as yet, little evidence that well controlled occupational exposure to industrial chemicals has led to clinically significant immunosuppression. In contrast, a number of industrial chemicals have been shown to cause immunopotentiation in exposed populations, producing occupational @entity565 and @entity5526 and possibly @entity792 . In experimental models, immunosuppression (usually assessed by in vivo or in vitro immune function tests) has been induced by a wide range of chemicals but there are a few reports of the immunosuppression leading directly to an increased susceptibility to @entity281 or to the development of @entity5 . Predictive experimental models are available for type @entity56 , but the identification of chemicals that have a potential to cause other types of @entity566 or autoimmune reactions requires further research and the development and validation of new animal models. It is considered that routine subacute and chronic @entity137 studies should include a full gross and histopathological assessment of the lymphoid organs to more accurately detect the potential of a chemical to cause immunotoxicity. Should such studies indicate that a substance has affected the immune system directly, an assessment of overall immune competence and function tests may be necessary using dose levels below those which cause @entity137 . However, precise interpretation of immune function tests in terms of their relevance to @entity1 health requires an improved understanding of the extent of the functional reserve of the immune system. A strategy for assessing immunotoxicity in exposed @entity1 populations demonstrates a need for reliable clinical assessment, accurate medical record-keeping, an environmental and biological monitoring for levels of contaminating chemicals and the judicious use of well-validated immune function tests.
