Age-related plasma reference ranges for two heparin-binding proteins--vitronectin and platelet factor 4.
This study was conducted to establish age-related reference ranges for two heparin-binding proteins--vitronectin and platelet factor 4 (PF4)--and to determine if the quantitative values of these proteins may contribute to the reported age-dependent effect of unfractionated heparin (UFH). Plasma samples were obtained from healthy children aged between 1 month and 16 years and from healthy adult volunteers. Two commercial kits were used to measure plasma vitronectin and PF4 levels. Results were reported as mean and boundaries including 95% of the population. Plasma vitronectin levels for children aged 1-5 years were significantly higher compared with adults. Plasma PF4 levels for infants <1 year of age were significantly lower compared with adults. The differences between reference values for both proteins in all other age-groups were not statistically significant. This study for the first time has established age-related reference ranges for vitronectin and PF4. In establishing these ranges, the quantitative values of these proteins do not appear to be the major contributory cause for the age-dependent variation in UFH effect. Future studies are required to evaluate the possible impact of age-dependent differences in binding between heparin-binding proteins and UFH.
Newall
F
F
Department of Pathology, The University of Melbourne, Parkville, Melbourne, Vic., Australia. fiona.newall@rch.org.au
Johnston
L
L
Ignjatovic
V
V
Summerhayes
R
R
Monagle
P
P
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D006493:Heparin / Q000378:metabolism*; D006801:Humans; D007223:Infant; D010978:Platelet Factor 4 / Q000097:blood*; D011485:Protein Binding; D019096:Vitronectin / Q000097:blood*
D019096:Vitronectin; D010978:Platelet Factor 4; D006493:Heparin