Campbell J R, Hillier S L, Krohn M A, Ferrieri P, Zaleznik D F, Baker C J
Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.
Obstet Gynecol. 2000 Oct;96(4):498-503. doi: 10.1016/s0029-7844(00)00977-7.
To describe the relationship between serum concentration of group B streptococcal capsular polysaccharide-specific immunoglobulin (Ig) G, colonization status, race or ethnicity, and age in pregnant women.
Pregnant women (n = 3307) were enrolled from geographically and ethnically diverse populations. At the time of admission for delivery, swabs of the lower vagina and rectum were obtained for isolation of group B streptococci. In a subset of women whose sera were available, capsular polysaccharide-specific IgG concentrations were quantified by serotype-specific (Ia, Ib, II, III, and V) enzyme-linked immunosorbent assay and compared by group B streptococcal colonization status.
Group B streptococcal colonization was detected in 856 women (26%), and the rate was significantly higher among black women (37%) than in other racial or ethnic groups (odds ratio 1.7, 95% confidence interval 1.4, 2.1). Colonization status did not differ by study site or age. Colonization with serotypes Ia, II, III, or V was associated with significantly higher serum concentrations of IgG specific for the capsular polysaccharide of the colonizing serotype compared with noncolonization. However, 48% of colonized women had low capsular polysaccharide-specific IgG levels (less than 0.5 microg/mL) in their delivery sera. Colonized teenagers had the lowest median concentration.
Colonization with group B streptococcus can elicit a systemic immune response, with a cumulative increase in the prevalence of capsular polysaccharide-specific IgG with increasing age. Conversely, low antibody levels in colonized teenagers might account in part for the reported increased risk of group B streptococcal disease in neonates born to these patients.
描述孕妇血清中B族链球菌荚膜多糖特异性免疫球蛋白（Ig）G浓度、定植状态、种族或民族与年龄之间的关系。
从地域和种族多样的人群中招募了3307名孕妇。在入院分娩时，采集阴道下段和直肠拭子以分离B族链球菌。在一部分有血清样本的女性中，通过血清型特异性（Ia、Ib、II、III和V）酶联免疫吸附测定法定量测定荚膜多糖特异性IgG浓度，并根据B族链球菌定植状态进行比较。
在856名女性（26%）中检测到B族链球菌定植，黑人女性中的定植率（37%）显著高于其他种族或民族群体（优势比1.7，95%置信区间1.4，2.1）。定植状态在研究地点或年龄方面没有差异。与未定植相比，Ia、II、III或V血清型的定植与定植血清型荚膜多糖特异性IgG的血清浓度显著升高有关。然而，48%的定植女性在分娩时血清中的荚膜多糖特异性IgG水平较低（低于0.5μg/mL）。定植的青少年的中位数浓度最低。
B族链球菌定植可引发全身免疫反应，随着年龄的增长，荚膜多糖特异性IgG的患病率会累积增加。相反，定植青少年的抗体水平较低可能部分解释了这些患者所生新生儿中报告的B族链球菌疾病风险增加的原因。
