title: CD4 T-lymphocyte activation is associated with peak expiratory flow variability in childhood asthma.
abstract: BACKGROUND
  Asthma has been recognized as a chronic inflammatory disorder of the airway. We have investigated the relationships among the activation markers on lymphocytes, eosinophils, their serum products in the peripheral blood, and the variability of airway obstruction in childhood asthma.
  
  
  METHODS
  Twenty-two patients with atopic asthma (mean age, 12 years) were treated regularly and asked to measure their peak expiratory flow (PEF) twice daily for 7 days, Peripheral venous blood was obtained on day 8.
  
  
  RESULTS
  The absolute counts of CD4 T lymphocytes expressing the activation marker CD25 in the peripheral blood on day 8 correlated significantly with the values of the coefficient of variation (CV) of both morning PEF (p < 0.01) and night PEF (p < 0.05) obtained over 7 days, but those of CD8+/CD25+ T lymphocytes, those of CD23+ B lymphocytes, and the serum concentrations of soluble CD25 did not. The absolute counts of peripheral blood eosinophils also demonstrated a significant correlation with the CV values of both morning PEF (p < 0.01) and night PEF (p <0.05).
  
  
  CONCLUSIONS
  CD4 T-lymphocyte activation and increased counts of eosinophils in peripheral blood correlate with CV of PEF in patients with asthma, suggesting that CV of PEF is a good marker for assessing not only the variability of airway obstruction but also the degree of airway inflammation.
authors.affiliation: Department of Pediatric Allergy, Osaka Prefectural Habikino Hospital, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Doi
authors.forename: N
authors.initials: N
authors.lastname: Murayama
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: I
authors.initials: I
authors.lastname: Takamatsu
authors.forename: M
authors.initials: M
authors.lastname: Kameda
authors.forename: Y
authors.initials: Y
authors.lastname: Omoto
authors.forename: K
authors.initials: K
authors.lastname: Toyoshima
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001249:Asthma / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology*; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D010366:Peak Expiratory Flow Rate / Q000276:immunology*