title: Age-Related Changes in Immunological Factors and Their Relevance in Allergic Disease Development During Childhood.
abstract: OBJECTIVE
  Allergic diseases are triggered by Th2-mediated immune reactions to allergens and orchestrated by various immunological factors, including immune cells and cytokines. Although many reports have suggested that childhood is the critical period in the onset of allergic diseases and aging leads to alter the susceptibility of an individual to allergic diseases, age-related changes in various immunological factors in healthy individuals as well as their difference between healthy and allergic children have not yet been established.
  
  
  METHODS
  We investigated the ratio of Th1/Th2 cells and the levels of 22 allergy-related cytokines across all age groups in individuals who were classified as clinically non-atopic and healthy. We also examined their differences between healthy and allergic children to evaluate immunological changes induced by the development of allergic diseases during childhood.
  
  
  RESULTS
  The Th1/Th2 ratio rose gradually during the growth period including childhood, reaching peak values in the twenties-thirties age group. Th1/Th2 ratios were significantly lower in allergic children than in healthy controls, whereas 14 of 22 cytokines were significantly higher in allergic children than in healthy controls. On the other hand, there were no differences in Th1/Th2 ratios and cytokines between healthy and allergic adolescents.
  
  
  CONCLUSIONS
  In this study, age-related changes in Th1/Th2 ratios were found in normal controls across all age groups, and decreases in Th1/Th2 ratio were observed with increasing of 14 cytokines in allergic children. The results of this study may be helpful as reference values for both monitoring immunological changes according to aging in healthy individuals and distinguishing between normal and allergic subjects in terms of immune cells and soluble factors.
authors.affiliation: Division of Allergy and Chronic Respiratory Disease, Center for Biomedical Sciences, Korea National Institute of Health, Korea Center for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Chang
authors.affiliation: Division of Allergy and Chronic Respiratory Disease, Center for Biomedical Sciences, Korea National Institute of Health, Korea Center for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: Division of Allergy and Chronic Respiratory Disease, Center for Biomedical Sciences, Korea National Institute of Health, Korea Center for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Yeon Mi
authors.initials: YM
authors.lastname: Lim
authors.affiliation: Division of Allergy and Chronic Respiratory Disease, Center for Biomedical Sciences, Korea National Institute of Health, Korea Center for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Dankyu
authors.initials: D
authors.lastname: Yoon
authors.affiliation: Division of Allergy and Chronic Respiratory Disease, Center for Biomedical Sciences, Korea National Institute of Health, Korea Center for Disease Control and Prevention, Cheongju, Korea.
authors.forename: Jo Young
authors.initials: JY
authors.lastname: Son
authors.affiliation: Department of Internal Medicine and Institute of Allergy, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jung Won
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Pediatrics, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Soo Jong
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sang Heon
authors.initials: SH
authors.lastname: Cho
authors.affiliation: Division of Allergy and Chronic Respiratory Disease, Center for Biomedical Sciences, Korea National Institute of Health, Korea Center for Disease Control and Prevention, Cheongju, Korea. jooshil@korea.kr.
authors.forename: Joo Shil
authors.initials: JS
authors.lastname: Lee
keywords: Allergy; Th1/Th2 ratio; chemokine; childhood; cytokine