title: Iridium alters immune balance between T helper 1 and T helper 2 responses.
abstract: The recent introduction of iridium (Ir) into the catalytic converter has resulted in an increase of Ir levels into the environment, especially ambient air and soil. These observations suggested the need to evaluate potential toxicity due to Ir exposure. Since Ir compounds have been previously shown to cause immune sensitization in humans, the effects of Ir via drinking water for 90 days was assessed in adult female Wistar rats with respect to selected immune parameters. The Ir exposure induced dose-dependent decrease (p < .01) in T helper 1 (Th1) cytokines and increase (p < .001) in a T helper 2 (Th2) cytokine. The findings show that the Ir exposure affects an immune imbalance with a skewing toward a Th2 bias, a risk factor for asthma.
authors.affiliation: Institute of Occupational Medicine, Catholic University of Sacred Heart, Largo Francesco Vito 1, Rome, Italy.
authors.forename: Ivo
authors.initials: I
authors.lastname: Iavicoli
authors.forename: Luca
authors.initials: L
authors.lastname: Fontana
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marinaccio
authors.forename: Antonio
authors.initials: A
authors.lastname: Bergamaschi
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Calabrese
mesh_terms: D000818:Animals; D002712:Chlorides / Q000633:toxicity*; D016207:Cytokines / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D007371:Interferon-gamma / Q000097:blood; D007376:Interleukin-2 / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D007495:Iridium / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D018570:Risk Assessment; D018417:Th1 Cells / Q000187:drug effects* / Q000276:immunology; D018418:Th2 Cells / Q000187:drug effects* / Q000276:immunology; D013997:Time Factors
chemical_list: D002712:Chlorides; D016207:Cytokines; D004785:Environmental Pollutants; D007376:Interleukin-2; C538735:iridium chloride; D015847:Interleukin-4; D007495:Iridium; D007371:Interferon-gamma