Screening and function studies in immunotoxicity testing.

Abstract

After a short introduction of various chemical of environmental concern that have been shown to alter cell-mediated or humoral immune responses, a screening procedure is given to detect possible immunotoxic properties of chemicals. The different parameters in this screening programme include growth, weight and histology of lymphoid and endocrine organs, haematology, as well as serum immunoglobulin concentrations. Next, different functional tests are discussed to assess the cell-mediated immunity, the humoral immunity, and the phagocytosis by macrophages in the rat. These tests should be performed when in a screening study an indication of immunotoxicity is found at a relevant dose level. The aim of functional assessment is to determine the functional significance of an effect on the immune response. As the data available at present clearly show that the developing organism is more at risk to the immunomodulating effects of different chemicals than the corresponding adult, functional assessment of immune effects should preferably be carried out after combined pre- and postnatal exposure.