Immunotoxicity definition

The US-EPA OPPTS test guideline on immunotoxicity (OPPTS 870.7800) provides the following definition Immunotoxicity refers to the ability of a test substance to suppress immune responses that could enhance the risk of infectious or neoplastic disease, or to induce inappropriate stimulation of the immune system, thus contributing to allergic or autoimmune disease. ... 

As indicated in Figure 1, the other side of the immunotoxicity continuum is manifested either as a hypersensitivity response or as an autoimmune disease. A hypersensitivity response is an acquired immune response (i.e., by definition, it is manifested on second contact with a particular antigen) which... 

The TDAR assay is believed to be one of the more predictive functional assays for assessing the immunotoxicity potential of drug candidates. This assay could be used to investigate the functional consequences of alterations seen in repeated-dose toxicity studies and/or clinical trials, and to provide an early read on the immunomodulatory potential of discovery candidates. The TDAR assay has been shown to predict immunotoxicity hazard. However, because of the inherent inter-animal variability seen in the TDAR particularly in outbred species, the assay should not be used as the definitive test but as an integral component of a weight-of-evidence approach for evaluating immunotoxicity risk. 

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