title: Complement system in healthy term newborns: reference values in umbilical cord blood.
abstract: Activation of the complement system occurs in several diseases. For reliable identification of complement activation in neonates, we establish reference ranges of several components in cord blood of healthy term newborns. For this study, cord blood samples were taken from 125 healthy term newborns. Concentrations of C1r, C2, C5, C7, Properdin, and factors D, H, and I were determined by single radial immunodiffusion. C3a and C5a were measured by specific EIA and complement function was measured by hemolytic assays. The results were expressed as 5th percentile, median, and 95th percentile. The following respective concentrations were found: C1r: 27, 47, 65 mg/l; C2: 12.0, 18.0, 24.0 mg/l; C5: 64, 92, 127 mg/l; C7: 32, 60, 89 mg/l; Properdin: 5.6, 9.7, 14.2 mg/l; factor D: 3.6, 5.2, 7.3 mg/l; factor H: 178, 234, 296 mg/l; and factor I: 15, 24, 32 mg/l. The functional activity of the whole complement system was 24%, 43%, 97% and for the alternative pathway 39%, 58%, 76%. The concentration of the activated split products C3a was 4, 65, 255 microg/l and of C5a, 0.11, 0.26, 1.19 microg/l. These reference values may be important for the detection of deficiencies of native complement proteins or perinatal processes leading to an activation of the complement system.
authors.affiliation: Department of Neonatology, Charité-Virchow-Hospital, Humboldt University Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Sonntag
authors.forename: U
authors.initials: U
authors.lastname: Brandenburg
authors.forename: D
authors.initials: D
authors.lastname: Polzehl
authors.forename: E
authors.initials: E
authors.lastname: Strauss
authors.forename: M
authors.initials: M
authors.lastname: Vogel
authors.forename: J W
authors.initials: JW
authors.lastname: Dudenhausen
authors.forename: M
authors.initials: M
authors.lastname: Obladen
mesh_terms: D000328:Adult; D002821:Chorioamnionitis / Q000097:blood / Q000473:pathology; D003165:Complement System Proteins / Q000032:analysis*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D008297:Male; D010920:Placenta / Q000473:pathology; D011247:Pregnancy; D012016:Reference Values; D012727:Sex Characteristics
chemical_list: D003165:Complement System Proteins