Zilow E P, Hauck W, Linderkamp O, Zilow G
Department of Pediatrics, University of Heidelberg, Germany.
Pediatr Res. 1997 Mar;41(3):334-9. doi: 10.1203/00006450-199703000-00005.
The increased incidence of infection in preterm neonates has been related in part to their relative deficiency of most complement components, because complement is known to participate in the defense against bacterial and viral infections. In a prospective study, complement activation products were determined in 52 preterm infants. Twenty preterm infants suffered from proven early onset infection, 11 infants were presumed to suffer from infection, which could not be confirmed. Twenty-one preterm infants without infection or perinatal asphyxia formed the control group. EDTA plasma was obtained within the first 6 h after birth, and follow-up examinations were done in 15 patients with proven infection during the next 24 h. The complement activation products C3a-desArg, C3bBbP, and sC5b-9 were measured with enzyme immunoassay systems. In preterm neonates with early onset infection, a significant elevation of C3a-desArg was found in the very early course of the disease. C3a-desArg generation resulted from alternative pathway activation as shown by a concurrent increase of C3bBbP concentration. In addition, significantly higher concentrations of sC5b-9 predicted infection in the first few hours after birth. Thus, despite very low levels of native complement proteins, preterm babies are able to generate remarkable amounts of activation products of the complement cascade. The elevation of these activation products preceded by hours significant changes of routine laboratory markers of infection, such as leukocyte count, differential blood count, and C-reactive protein. Thus they might help to identify preterm neonates with severe systemic infection earlier than other laboratory parameters.
早产儿感染发生率增加部分与大多数补体成分相对缺乏有关，因为已知补体参与抵御细菌和病毒感染。在一项前瞻性研究中，对52名早产儿的补体激活产物进行了测定。20名早产儿患有经证实的早发型感染，11名婴儿被推测患有感染但无法确诊。21名无感染或围产期窒息的早产儿组成对照组。在出生后6小时内采集乙二胺四乙酸（EDTA）血浆，并在接下来的24小时内对15名经证实感染的患者进行随访检查。采用酶免疫分析系统测定补体激活产物C3a-去精氨酸（C3a-desArg）、C3bBbP和sC5b-9。在早发型感染的早产儿中，在疾病极早期就发现C3a-desArg显著升高。C3bBbP浓度同时升高表明C3a-desArg的产生源于替代途径的激活。此外，出生后最初几个小时内sC5b-9浓度显著升高预示着感染。因此，尽管天然补体蛋白水平极低，早产儿仍能够产生大量补体级联反应的激活产物。这些激活产物的升高比感染的常规实验室指标如白细胞计数、血细胞分类计数和C反应蛋白的显著变化提前数小时。因此，它们可能比其他实验室参数更早地有助于识别患有严重全身感染的早产儿。
