Gotoff S P, Odell C, Papierniak C K, Klegerman M E, Boyer K M
J Infect Dis. 1986 Mar;153(3):511-9. doi: 10.1093/infdis/153.3.511.
We determined the serum concentration of human IgG antibody to the native capsular polysaccharide of group B Streptococcus (GBS) type III needed to passively protect mice against lethal homologous challenge. Antibody was measured by an ELISA, standardized by two methods, and corrected for nonprecipitating antibody. A concentration of 1.3 micrograms of IgG antibody to GBS type III/ml protected 126 (97%) of 130 mice from an 80%-96% lethal dose bacterial challenge. Concentrations of IgG antibody to GBS type III in sera from 42 infected infants were less than or equal to 0.3 micrograms/ml. Concentrations of antibody ranged from less than 0.02 to 21.7 micrograms/ml in sera from 102 unselected pregnant women (median, 0.05 microgram/ml); 13% had concentrations greater than or equal to 1.3 microgram/ml. Levels in 25 women colonized with GBS type III who gave birth to normal infants were significantly higher and ranged from 0.1 to 10.7 microgram/ml (median, 0.78 micrograms/ml). In a study of transplacental passage of antibody, protective levels were found in a number of infants with gestational ages between 28 and 36 weeks.
我们测定了针对B族链球菌（GBS）III型天然荚膜多糖的人IgG抗体的血清浓度，该浓度需要被动保护小鼠免受致命的同源攻击。通过酶联免疫吸附测定法（ELISA）测量抗体，用两种方法进行标准化，并对非沉淀抗体进行校正。每毫升含有1.3微克针对GBS III型的IgG抗体的浓度可保护130只小鼠中的126只（97%）免受80%-96%致死剂量的细菌攻击。42名受感染婴儿血清中针对GBS III型的IgG抗体浓度小于或等于0.3微克/毫升。在102名未经挑选的孕妇血清中，抗体浓度范围为小于0.02至21.7微克/毫升（中位数为0.05微克/毫升）；13%的孕妇抗体浓度大于或等于1.3微克/毫升。25名携带GBS III型且分娩出正常婴儿的女性体内的抗体水平明显更高，范围为0.1至10.7微克/毫升（中位数为0.78微克/毫升）。在一项关于抗体经胎盘传递的研究中，在许多胎龄为28至36周的婴儿体内发现了具有保护作用的抗体水平。
