title: Cytokine Patterns in Healthy Adolescent Girls: Heterogeneity Captured by Variable and Person-Centered Statistical Strategies.
abstract: Little is known about variation in individual cytokines/cytokine profiles for a large healthy, pediatric population. When cytokines in a healthy group are not abnormally high as in a disease state, it is challenging to determine appropriate statistical strategies. The aims of the study were (1) to describe variation among cytokine concentrations and profiles in healthy adolescent girls, (2) to illustrate utility of data reduction approaches novel to cytokine research, (variable-centered [principal factor analysis, PFA], person-centered [latent profile analysis, LPA]), and (3) to demonstrate utility of such methods in linking cytokine profiles to health outcomes (e.g., depressive, anxiety symptoms).
  
  
  
  Serum was analyzed for 13 cytokines representing adaptive and innate immune responses in 262 girls (age = 11, 13, 15, and 17 years).
  
  
  
  There was great variation in cytokine concentrations. PFA revealed a four-factor solution explaining 73.13% of the shared variance among 13 cytokines (e.g., factor 1 included interleukin [IL]-4, IL-13, IL-5, interferon gamma; 26.65% of the shared variance). The LPA supported classifying girls into subgroups characterized by "high overall" (7.3% of sample), "high adaptive" (26.7%), "high innate" (21%), or "low overall" (45%) cytokine levels. Factors and profiles were useful in describing individual differences in depressive/anxiety symptoms (e.g., factor 1 positively associated with depressive symptoms but negatively with trait anxiety; increased depressive symptoms or trait anxiety was associated with greater likelihood of being in the "high adaptive" group).
  
  
  
  Healthy girls showed differences in cytokine levels and patterns of variation and important associations with psychological variables. PFA and LPA offer novel approaches useful for examining cytokine panels in healthy populations.
authors.affiliation: From the College of Nursing (Dorn, Engeland), The Pennsylvania State University; Prevention Research Center (Gayles), The Pennsylvania State University; Department of Biobehavioral Health (Engeland), The Pennsylvania State University, University Park, Pennsylvania; Department of Psychology and Neuroscience (Houts), Duke University, Durham, North Carolina; National Institute of Child Health and Human Development (Cizza), National Institutes of Health, Bethesda, Maryland; Pediatric Gastroenterology (Denson), Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; and University of Cincinnati School of Medicine (Denson), Cincinnati, Ohio.
authors.forename: Lorah D
authors.initials: LD
authors.lastname: Dorn
authors.forename: Jochebed G
authors.initials: JG
authors.lastname: Gayles
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Engeland
authors.forename: Renate
authors.initials: R
authors.lastname: Houts
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cizza
authors.forename: Lee A
authors.initials: LA
authors.lastname: Denson
mesh_terms: D000293:Adolescent; D041923:Adolescent Development / Q000502:physiology*; D001007:Anxiety / Q000097:blood*; D002648:Child; D016207:Cytokines / Q000097:blood*; D003863:Depression / Q000097:blood*; D005260:Female; D006801:Humans; D007206:Individuality
chemical_list: D016207:Cytokines