title: Concentrations of C1q, factor B, factor D and properdin in healthy children, and the age-related presence of circulating C1r-C1s complexes.
abstract: The concentrations of C1q, factor B, factor D and properdin were determined in healthy children belonging to various age groups of one through five years of age. All concentrations were found to be age-dependent, though they varied from one component to another with regard to ontogenetic pattern. Thus, the concentrations of factor B were high, and those of factor D low throughout the age range studied. C1q and properdin levels were lowest in the younger children, who also showed a fairly high incidence of C1r-C1s complexes in excess of C1q. Since the concentrations of C1q are influenced by those of IgG, the presence of C1r-C1s complexes might partly have reflected maturation of immunoglobulin synthesis during ontogeny.
authors.affiliation: Department of Oto-Rhino-Laryngology, University of Lund, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Prellner
authors.forename: A G
authors.initials: AG
authors.lastname: Sjöholm
authors.forename: L
authors.initials: L
authors.lastname: Truedsson
mesh_terms: D000367:Age Factors; D002675:Child, Preschool; D003166:Complement Activating Enzymes / Q000032:analysis; D003172:Complement C1 / Q000032:analysis; D015922:Complement C1q; D015923:Complement C1r; D003173:Complement C1s / Q000032:analysis; D011415:Complement Factor B / Q000032:analysis; D011416:Complement Factor D / Q000032:analysis; D003165:Complement System Proteins / Q000032:analysis*; D006801:Humans; D007223:Infant; D011414:Properdin / Q000032:analysis; D012016:Reference Values
chemical_list: D003172:Complement C1; D011414:Properdin; D015922:Complement C1q; D003165:Complement System Proteins; D003166:Complement Activating Enzymes; D015923:Complement C1r; D003173:Complement C1s; C493488:CFD protein, human; D011416:Complement Factor D; D011415:Complement Factor B