title: Severe neonatal protein C deficiency: prevalence and thrombotic risk.
abstract: Severe deficiencies of protein C, a pivotal coagulation-regulatory protein, have been reported in neonates as an apparently transient condition. In this prospective study, cord blood was collected at 193 deliveries and assays of protein C were correlated with clinical status, other coagulation results, and outcome. Protein C levels of less than 0.1 unit/ml were found most frequently in preterm infants with respiratory distress, infants of diabetic mothers, and infants of twin gestations. Levels of protein C correlated with levels of factor VIII activity but did not correlate with markers of consumptive coagulopathy. A protein C level less than 0.1 unit/ml was significantly correlated with the subsequent onset of thrombosis, even when the effects of gestational age and birth weight were excluded. Low cord blood levels of protein C may reflect delayed maturation or increased turnover in certain infants and appear to convey an independent risk of thrombosis, but the critical concentration of protein C necessary to maintain neonatal hemostasis is not known.
authors.affiliation: Department of Pediatric Hematology, University of Colorado Health Sciences Center, Denver.
authors.forename: M J
authors.initials: MJ
authors.lastname: Manco-Johnson
authors.forename: T C
authors.initials: TC
authors.lastname: Abshire
authors.forename: L J
authors.initials: LJ
authors.lastname: Jacobson
authors.forename: R A
authors.initials: RA
authors.lastname: Marlar
mesh_terms: D000990:Antithrombin III / Q000032:analysis; D001798:Blood Proteins / Q000032:analysis; D002352:Carrier Proteins / Q000097:blood; D003120:Colorado / Q000453:epidemiology; D004211:Disseminated Intravascular Coagulation / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D005312:Fetal Blood / Q000737:chemistry; D006023:Glycoproteins / Q000097:blood; D015844:Heparin Cofactor II / Q000032:analysis; D006801:Humans; D007231:Infant, Newborn; D015995:Prevalence; D011486:Protein C / Q000032:analysis / Q000037:antagonists & inhibitors; D020151:Protein C Deficiency; D017293:Protein S; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood / Q000453:epidemiology* / Q000209:etiology
chemical_list: D001798:Blood Proteins; D002352:Carrier Proteins; D006023:Glycoproteins; D011486:Protein C; D017293:Protein S; D015844:Heparin Cofactor II; D000990:Antithrombin III