title: Passive smoking alters circulating naïve/memory lymphocyte T-cell subpopulations in children.
abstract: While it has been indicated that exposure to second-hand smoke (SHS) can cause a local in vivo response, limited evidence exists on its possible systemic effects from population-based levels of exposure. We investigated into a possible systemic response in the immune parameters and lymphocyte subsets, i.e. B cell (CD19+), T cell (CD4+CD45RO+, CD4+CD45RA+, CD3+CD45RO+, CD3+CD45RA+) and natural killer (CD3+CD16CD56+) lymphocyte subsets relative to exposure to SHS. Blood was drawn from healthy, verified non-smoker, adolescent subjects (n = 68, mean age 14.2) and analysed for cotinine, antioxidants and lymphocyte immunophenotyping. SHS exposure was assessed using serum cotinine. Biomarker quantified exposure to SHS was correlated with a linear dose-response reduction in the percentages of memory CD4+CD45RO+ (p = 0.005) and CD3+CD45RO+ T-cell subsets (p = 0.005 and p = 0.003, respectively) and a linear increase in the percentage of naïve CD4+CD45RA+ and CD3+CD45RA+ T-cell subsets (p = 0.006 and p = 0.003, respectively). Additionally, higher exposure to SHS was associated with a higher CD4+CD45RA+ count (532 vs. 409 cells/ml, p = 0.017). Moreover, after controlling for age, gender, body mass index and plasma antioxidants, SHS exposure was found to be associated with the percentage of circulating naïve and memory CD4+ and CD3+ T-cell subpopulations, as revealed through a linear regression analysis. These findings indicate a systemic immunological response in healthy adolescents exposed to population-based levels of SHS exposure and imply an additional biological pathway for the interaction between exposure to SHS and its adverse effects on human health.
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, Crete, Greece. vardavas@edu.med.uoc.gr
authors.forename: Constantine I
authors.initials: CI
authors.lastname: Vardavas
authors.forename: Maria
authors.initials: M
authors.lastname: Plada
authors.forename: Manolis
authors.initials: M
authors.lastname: Tzatzarakis
authors.forename: Ascension
authors.initials: A
authors.lastname: Marcos
authors.forename: Julia
authors.initials: J
authors.lastname: Warnberg
authors.forename: Sonia
authors.initials: S
authors.lastname: Gomez-Martinez
authors.forename: Christina
authors.initials: C
authors.lastname: Breidenassel
authors.forename: Marcela
authors.initials: M
authors.lastname: Gonzalez-Gross
authors.forename: Aristeidis M
authors.initials: AM
authors.lastname: Tsatsakis
authors.forename: Wim H
authors.initials: WH
authors.lastname: Saris
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Kafatos
mesh_terms: D000293:Adolescent; D015703:Antigens, CD / Q000378:metabolism; D000943:Antigens, Differentiation / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D002648:Child; D003367:Cotinine / Q000097:blood; D005060:Europe; D006801:Humans; D007156:Immunologic Memory; D016130:Immunophenotyping; D044382:Population Groups; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects / Q000517:prevention & control
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D015415:Biomarkers; D014028:Tobacco Smoke Pollution; D003367:Cotinine