Immunotoxicity hazard identification

The basis of the recommended approach to a hazard assessment of the potential immunotoxicity of a substance is that many immunotoxic substances can be identified via the standard tests for systemic toxicity. Special smdies to characterize effects of concern for immunotoxicity are used only when necessary for adequate hazard assessment. The nature of special smdies, and when they should be conducted, need to be decided on a case-by-case basis. A tiered approach to the identification of immunotoxic hazard in routine toxicology is described in WHO/IPCS (1996). 

The objective of this section is to provide a description of several immune parameters and methodologies that are used in the preclinical setting to characterize immune hazards for human risk assessments. The utility of a standalone functional evaluation, specifically the rat T cell-dependent antibody response (TDAR) model developed for regulated immunotoxicity evaluations (Gore et al, 2004), is mainly used for hazard identification, i.e., unintended immunosuppression. This assay is based on an end point parameter that is the... 

Although immunophenotyping is part of many immunotoxicologic evaluations, it is unlikely to ever be a stand-alone analysis in risk assessment because of limited applicability as a screen for immunotoxicity. Despite not being a stand-alone technique and with only a limited role in hazard identification, immunophenotyping remains an important tool in hazard characterization, primarily in understanding mechanisms of immunotoxicity. 

---