title: Serum cytokine levels, cigarette smoking and airway responsiveness among pregnant women.
abstract: BACKGROUND
  Five to twenty percent of healthy, nonasthmatic individuals exhibit airway hyperreactivity. Because cytokines are important intermediates in airway responses, we investigated the relationship between serum cytokines and airway responsiveness in a well-characterized population of pregnant women.
  
  
  METHODS
  We analyzed serum levels of interleukin-4 (IL-4), IL-5, IL-6, interferon-gamma (IFN-gamma), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in frozen sera from 240 pregnant nonasthmatic subjects from a previous study of airway responsiveness and preterm labor for their relationship to methacholine challenge test results.
  
  
  RESULTS
  Serum IFN-gamma and GM-CSF levels were significantly related to levels of methacholine airway responsiveness among nonasthmatics in this population. Nonasthmatics with PD(20) <8 micromol (the highest level of airway responsiveness) had the highest mean serum levels of IFN-gamma and GM-CSF, those with 8 <or= PD(20) <or= >50 micromol had intermediate levels, and those with PD(20) >>50 mol had the lowest levels. Both serum IFN-gamma and GM-CSF levels were also significantly related to the log dose-response slope for methacholine responsiveness. These relationships were confirmed in a multiple linear regression analysis controlling for age, ethnic background, and cigarette smoking. Current smoking was uniformly associated with decreased cytokine levels.
  
  
  CONCLUSIONS
  IFN-gamma, GM-CSF, and other cytokines may be useful serum markers in population studies of airway responsiveness.
authors.affiliation: Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pa., USA.
authors.forename: Masashi
authors.initials: M
authors.lastname: Tsunoda
authors.forename: Augusto A
authors.initials: AA
authors.lastname: Litonjua
authors.forename: Michael P
authors.initials: MP
authors.lastname: Kuniak
authors.forename: Scott T
authors.initials: ST
authors.lastname: Weiss
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Satoh
authors.forename: Lucille
authors.initials: L
authors.lastname: Guevarra
authors.forename: David J
authors.initials: DJ
authors.lastname: Tollerud
mesh_terms: D000328:Adult; D000403:Airway Resistance / Q000276:immunology*; D044383:Black People; D016085:Bronchoconstrictor Agents / Q000494:pharmacology; D016207:Cytokines / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D016210:Methacholine Chloride / Q000494:pharmacology; D011247:Pregnancy / Q000097:blood / Q000276:immunology*; D012044:Regression Analysis; D012907:Smoking / Q000097:blood / Q000276:immunology*; D044465:White People
chemical_list: D016085:Bronchoconstrictor Agents; D016207:Cytokines; D016210:Methacholine Chloride; D007073:Immunoglobulin E