IMMUNOTOXIC EFFECTS OF XENOBIOTICS IN HUMANS - A REVIEW OF CURRENT EVIDENCE

Immunotoxic effects include immunosuppression and immunostimulation, hypersensitivity and autoimmunity. Infections and lymphoproliferative disorders have been associated with the use of immunosuppressive drugs, whereas infections have seldom been associated with chemical exposure. Fewer drugs and chemicals have been shown to enhance immune parameters. Clinical consequences, (i.e. flu-like syndromes, autoimmune reactions, facilitated allergic reactions to unrelated antigens and impaired hepatic drug metabolism) mostly have been associated with recombinant cytokines. Hypersensitivity reactions have commonly been reported in treated patients as well as in exposed workers. Autoimmune reactions have been associated with only a few drugs. Overall, current evidence suggests that marked immune changes in humans exposed to xenobiotics can result in overt clinical toxicities, but it remains to be established to what extent mild to moderate immune changes described in animals and/or humans can result in immune-mediated diseases. This issue could be investigated by the follow-up of selected cohorts, for example patients from clinical trials, exposed workers, or inhabitants of heavily polluted areas, using standardized and validated immunology assays, together with the identification of sentinel immune diseases.