Developmental hemostasis: age-specific differences in the levels of hemostatic proteins

IntroductionDevelopmental hemostasis recognizes the physiologic differences between the hemostatic system of neonates and children and that of adults. As compared with the knowledge of hemostatic system physiology in adults, our understanding in neonates and children remains inadequate. Routine clinical coagulation testing most commonly measures functional parameters of the hemostatic system. Very few studies have measured age-specific levels of hemostatic proteins. An understanding of the normal fluctuations in the levels of hemostatic proteins is vital in the prevention, diagnosis and treatment of hemostatic problems during infancy and childhood. This study was designed as the first comprehensive study of the age-specific changes in the levels of important hemostatic proteins in healthy neonates, children, and adults. MethodsPlasma samples were obtained from 120 healthy individuals from the following age groups: neonates (day1 and day3), 28days to 1year, 1-5years, 6-10years, 11-16years, and adults. FactorII, FV, FVII, FVIII, FIX, FX, FXI, FXII, FXIII, plasminogen, proteinC and total and free proteinS were quantified with commercially available ELISA kits. ResultsThe levels of 10 proteins were significantly different between neonates and adults, and these differences persisted throughout childhood for most of these proteins. ConclusionThe results of this study confirm that the levels of the majority of coagulation proteins vary significantly with age. Future studies should investigate how hemostatic protein level relates to functional changes with age.