In-Vivo-Aktivierung der vierten Komponente des Komplementsystems (C4) bei Früh- und Reifgeborenen mit generalisierten bakteriellen Infektionen

Abstract

The concentrations of the complement components C3 and C4 and their activation products C3dg and C4d were determined in EDTA-stabilized serum of 25 premature and term infants. EDTA plasma and EDTA serum obtained from 30 normal blood donors were used as controls. According to clinical, laboratory and/or microbiological findings, six of the 25 children had infections. The mean scatter range of the C3 and C4 values was from 30% (in the 30th week of pregnancy) to 80% (in term infants) of the normal value for adults. In all the children, irrespective of gestational age, the C3dg concentrations were of the same order of magnitude as in healthy adults. As regards the C3, C4, and C3dg values, there was no difference between the newborns with and without infections. The C4d values of the newborns without infections, on the other hand, (range 0.1-1.4 mg/dl, mean 0.8 mg/dl, n = 19) were significantly lower than those of the newborns with infections (range 1.3-2.4 mg/dl, mean 1.95 mg/dl, n = 6). Observation of the course and comparison with CrP showed that elevated C4d values may occur earlier. In the authors' view, these findings indicate that in bacterial infections of premature and term infants the fourth complement component is activated, while the extent to which the third complement component is involved in the activation process is not measurable. Further studies are needed to establish whether early diagnosis of neonatal sepsis can be improved by determining C4d.

Evaluation of complement activation in premature newborn infants with hyaline membrane disease

“…Plasma concentrations of C3dg, a degradation product of C3b by the action of factors H and I, were within the normal range of healthy adults. This is in accordance with reported data [20].…”

“…There was no evidence for complement activation in patients with HMD compared to a control group of healthy premature newborns. Levels of individual complement components have been shown to be significantly lower in infants than in adults, partly correlating with gestational age [7,15,20,27]. Plasma concentrations of CHS0, C3, C4 and C3d measured in our study group corresponded with reported data.…”

Comparative Study of Four Tests of Bacterial Infection in the Neonate

“…A first study showed that C3d was present in 6/7 cases of neonatal septicemia [2], These results are con sistent with observations made in adults by Vergani et al [9] who noted a rise in C3d in 20 cases of septicemia [9]. Pelet [12] found an increase in serum concentrations of C3 degra dation products in 2/11 septicemia newborn infants, while Nürnberger et al [ 13] found no increase in C3d in 6 infected children. Re cently, Miyano et al [11] found that the aver age level of C3d is significantly higher in chil dren born to mothers with chorioamnionitis than in those born to uninfected mothers.…”

International consensus on the diagnosis and management of pediatric patients with hereditary angioedema with C1 inhibitor deficiency

“…Both antigenic and functional C1‐INH cord blood levels correspond to 70% and 61.8% of adult normal values increasing to normal adult levels by the age of one year 71, 72. Moreover, neonatal serum complement levels are influenced by birth weight and gestational age 71, 73, 74. In newborns and infants aged less than 1 year, both C1‐INH antigenic level and functional activity are low in the patients with C1‐INH‐HAE type I and are within normal range in non‐C1‐INH‐HAE patients 68, 72.…”