title: The comparative immunotoxicity of five selected compounds following developmental or adult exposure.
abstract: It is well established that human diseases associated with abnormal immune function, including some common infectious diseases and asthma, are considerably more prevalent at younger ages. Although not established absolutely, it is generally believed that development constitutes a period of increased immune system susceptibility to xenobiotics, since adverse effects may occur at lower doses and/or immunomodulation may be more persistent, thus increasing the relative risk of xenobiotic exposure to the immunologically immature organism. To address this issue, a brief overview of immune maturation in humans is provided to demonstrate that functional immaturity alone predisposes the young to infection. Age-dependent differences in the immunotoxic effects of five diverse compounds, diethylstilbestrol (DES), diazepam (DZP), lead (Pb), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and tributyltin oxide (TBTO), which have undergone adult and developmental immunotoxicity testing in rodents, are then reviewed, as are human data when available. For all five chemicals, the developing immune system was found to be at greater risk than that of the adult, either because lower doses produced immunotoxicity, adverse effects were more persistent, or both.
authors.affiliation: Immunotoxicology Branch, Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA. luebke.robert@epi.gov
authors.forename: Robert W
authors.initials: RW
authors.lastname: Luebke
authors.forename: David H
authors.initials: DH
authors.lastname: Chen
authors.forename: Rodney
authors.initials: R
authors.lastname: Dietert
authors.forename: Yung
authors.initials: Y
authors.lastname: Yang
authors.forename: Marquea
authors.initials: M
authors.lastname: King
authors.forename: Michael I
authors.initials: MI
authors.lastname: Luster
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D003975:Diazepam / Q000633:toxicity*; D004054:Diethylstilbestrol / Q000633:toxicity*; D005333:Fetus / Q000187:drug effects*; D006801:Humans; D007107:Immune System / Q000187:drug effects*; D007109:Immunity / Q000187:drug effects; D007854:Lead / Q000633:toxicity*; D051379:Mice; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D051381:Rats; D014220:Trialkyltin Compounds / Q000633:toxicity*
chemical_list: D000072317:Polychlorinated Dibenzodioxins; D014220:Trialkyltin Compounds; D007854:Lead; C005961:bis(tri-n-butyltin)oxide; D004054:Diethylstilbestrol; D003975:Diazepam