title: Reference intervals for serum granulocyte colony-stimulating factor levels in children.
abstract: OBJECTIVE
  To determine age-adjusted reference intervals for children for serum granulocyte colony-stimulating factor (G-CSF) levels.
  
  
  METHODS
  We determined the serum G-CSF levels of 168 disease-free children who were term neonates to 15 years of age with a highly sensitive chemiluminescent enzyme immunoassay.
  
  
  RESULTS
  The lowest values (5 ng/L) exceeded the detectable limit (1 ng/L) of this assay technique. The G-CSF levels were highest on the day of birth (mean +/- SD 147 +/- 146 ng/L); thereafter values decreased to 46 +/- 33 ng/L in the early neonatal period and to 23 +/- 10 ng/L in the late neonatal period. The G-CSF levels both on the day of birth and in the early neonatal period were significantly higher than in all older age groups. No significant differences were found among any of the age groups after 4 weeks of age. The G-CSF values were correlated with both blood leukocyte counts (r = 0.496, p < 0.0001) and neutrophil counts (r = 0.547, p < 0.0001). In children older than 4 weeks of age (n = 128), the 95% reference interval for G-CSF values was 5 to 42 ng/L.
  
  
  CONCLUSIONS
  Our study in disease-free children revealed that change in serum G-CSF levels are age dependent and are correlated with neutrophil counts. Determination of reference intervals for the neonatal period requires further study.
authors.affiliation: Department of Pediatrics, Mizonokuchi Hospital, Teikyo University School of Medicine, Kawasaki, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Ishiguro
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Nakahata
authors.forename: H
authors.initials: H
authors.lastname: Nishihira
authors.forename: S
authors.initials: S
authors.lastname: Kojima
authors.forename: K
authors.initials: K
authors.lastname: Ueda
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Shimbo
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000097:blood*; D006801:Humans; D007223:Infant; D007958:Leukocyte Count; D008163:Luminescent Measurements; D008297:Male; D009504:Neutrophils; D012016:Reference Values; D012189:Retrospective Studies
chemical_list: D016178:Granulocyte-Macrophage Colony-Stimulating Factor