title: Pediatric reference values for molecular markers in hemostasis.
abstract: BACKGROUND
  The hemostatic system is a developing and changing process relative to age.
  
  
  OBJECTIVE
  To distinguish the differences in hemostatic parameters between children and adults, and to establish the normal range of these parameters in children of different age groups.
  
  
  METHODS
  Blood was obtained from healthy children aged 1 to 18 years (n=70) and adults (n=26). Children were categorized into 3 age groups: 1 to 5 years, 6 to 10 years, and 11 to 18 years. Several coagulation and fibrinolysis parameters were determined.
  
  
  RESULTS
  Children in all age groups showed no significant difference in mean levels of von Willebrand factor antigen and activity, activated partial thromboplastin time, fibrinogen, activated factor VII, tissue plasminogen activator, plasminogen activator inhibitor-1, and thrombin activatable fibrinolysis inhibitor compared with adults. However, children aged 1 to 5 years had significantly higher mean values of soluble thrombomodulin (P=0.001), prothrombin time (P=0.03), tissue factor (P<0.001), thrombin-antithrombin complex (P<0.001), and D-dimer (P=0.009) whereas they had significantly lower mean levels of protein C activity (P=0.02) than did adults.
  
  
  CONCLUSIONS
  These data indicate physiologic differences in the hemostatic system between children and adults and should serve as a useful reference guide in interpreting test results for children with suspected bleeding disorders.
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Rama IV Road, Bangkok 10330, Thailand. dsosothikul@hotmail.com
authors.forename: Darintr
authors.initials: D
authors.lastname: Sosothikul
authors.forename: Panya
authors.initials: P
authors.lastname: Seksarn
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Lusher
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology*; D015415:Biomarkers / Q000032:analysis; D001798:Blood Proteins / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006470:Hemorrhage / Q000097:blood / Q000175:diagnosis; D006487:Hemostasis / Q000502:physiology*; D006801:Humans; D007223:Infant; D008297:Male; D012016:Reference Values
chemical_list: D015415:Biomarkers; D001798:Blood Proteins