Human complement C7 and C9 in fetal and newborn sera.

Abstract

. Human complement C7 and C9 in fetal and newborn sera. Using specific immune sera, C7, C9, and C3 activator were detected in sera from human fetuses more than 16 weeks old and in newborn samples. Levels of C9 in cord sera ranged between 10 and 300/o of those present in sera from adult subjects. The mean value of C3 activator was about half that in maternal blood. The mean level of C7 in newborns was nearly 700o of the amount in normal adults.The availability of antibodies to specific components of human complement (C) and the analysis of in vitro cultures of fetal tissues have made it possible to study the onset and site of synthesis of these proteins during fetal life (Adinolfi, 1972;Rosen, 1974). The studies of the ontogeny of complement so far published have shown that Cl, C3, C4, and C5 are produced by the human fetus at an early stage of gestation (Adinolfi and Gardner, 1967;Adinolfi, Gardner, and Wood, 1968;Gitlin and Biasucci, 1969; Colten, 1972, Kohler;1973).We report preliminary results of our investigations on the presence and estimation of C3 activator, C7, and C9 in sera from human fetuses and newborns. Materials and methodsTwenty-four samples of cord blood were collected by syringe from the umbilical vein. Blood from normal adult individuals was taken by venepuncture. Serum was separated from clotted blood as soon as possible and the samples stored at -20°for no more than 2 months before being used. Blood was also collected by cardiac puncture from 5 fetuses whose ages, calculated from crown-rump length, ranged between 14 and 25 weeks. Most of the fetuses were obtained from therapeutic abortions.Immune serum against C3 activator (factor B) was obtained from Behringwerke (Marburg, Germany) and it was raised against one of the breakdown products of factor B. The rabbit immune sera against C7 and C9 were made by injection of precipitin lines cut from immunoelectrophoretic plates using anti-C7 and anti-C9 (kindly donated by Dr. H. Y. Muiller-Eberhard, Received 9 December 1974. U.S.A.). Both antisera gave only one line of precipitation when tested by double diffusion in agar gel.The presence of C7 and C9 in fetal and newborn sera was investigated using double diffusion in agar gel. Levels of C3 activator and C7 were measured by the single radial diffusion method, using a minor modification of the technique described by Kohler and MullerEberhard (1967). Levels of C7 were also estimated with the agarose plate technique (Lachman, Hobart and Aston, 1973) using guinea pig red cells and C56 euglobulin prepared from sera collected from normal women after childbirth. Concentrations of C9 were estimated by comparing the patterns of precipitations of serial dilutions of a normal adult serum with those of fetal and newborn samples.In the present paper the amount of C3 activator is expressed in mg/100 ml, using a standard serum provided by Behringwerke (Marburg, Germany), and levels of C7 and C9 in fetal and newborn sera are expressed as a percentage of the amount detected in adult samples.

Off to a slow start: Under-development of the complement system in term newborns is more substantial following premature birth

“…studied C5 C6 C7 C8 C9 Arinola et al (2003) T 55 67 Sonntag et al (1998a) T 125 76 106 Wolach et al (1997) T (>37 weeks) 1 48, 2 35, 3 23, 4 28, 5 15 1 70 2 58 3 95 4 36 5 55 Wolach et al (1994) T 1 47, 2 30, 3 17 1 72 2 55 2 97 2 38 3 50 Lassiter et al (1992) T 14 <20 Adinolfi et al (1981) T 28 18 Johnson et al (1983) b T 100 79 (64) 44 (31) 120 (91) 38 (29) Ueda et al (1980) Davis et al (1979) T 1 0 7 5 4 7 Adinolfi and Beck (1975) T To analyse complement components, radial immunodiffusion is the method used in all of the above studies except that of Johnson et al (1983), in which C5 was analysed using electroimmunoassay and C7 was analysed using immunoelectrophoresis. a Hogasen et al (2000) in which C9 is analysed using ELISA.…”

“…The family of three ficolins (L, H and M) are Notarangelo et al (1984) T 25 Johnson et al (1983) T 100 87 (55) 54 (37) 120 (144) 50 (55) Adinolfi et al (1981) T 24 73 Shapiro et al (1981) T 1 1 9 7 6 1 Ueda et al (1980) Drew and Arroyave (1980) T 11 59 33 Strunk et al (1979) b T 20 60 36 71 Davis et al (1979) T 10 49 53 Feinstein and Kaplan (1975) T 51 80 53 Adinolfi and Beck (1975) T 22 47 Wagner et al (1996) P/T (median 38.5 weeks) 12 48 a Miyano et al (1996) P/T (mean 33.6 weeks) 131 31 a Adamkin et al (1978) P/T ( To analyse complement components, radial immunodiffusion is the method used in all of the above studies except where # indicates these values were determined by ELISA method. a Value calculated from data using adult reference value stated in Shapiro et al (1981).…”

Complement Activation in Newborn Infants with Early Onset Infection

“…Because levels of maternal complement rise during pregnancy, this corresponds to a higher percentage compared with normal adults (7). Plasma concentration of C7 in neonates is about 70% of the adult value (25). and levels of C8 and C9 are about 10 to 25% of the value in normal adults (3).…”

Alternative Pathway of Complement Activation in Full Term and Premature Infants

“…Several other studies of the classical complement pathway in newborn sera have demonstrated that levels of whole complement activity and individual components are lower in cord sera than the levels in paired maternal sera or in normal adult sera (1,3,6,13). As in these other studies, our data indicate that levels of both whole classical complement activity and the components C3 and C4 were grossly different than the levels in adult controls.…”

“…The serum complement system is one of the major humoral defense mechanisms required for effective clearance of bacteria (7). Several investigators have found both the activity of the classical complement pathway and levels of its specific components are low in infant cord blood when compared to adult levels (1,3,6,13). The degree of depression of these levels tends to correlate positively with birth weight.…”