Specificities and opsonophagocytic activities of antibodies to pneumococcal capsular polysaccharides in sera of unimmunized young children
Specificities and opsonophagocytic activities of antibodies to pneumococcal capsular polysaccharides in sera of unimmunized young children
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DOI：
10.1128/cdli.9.5.1032-1038.2002
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发表时间：
2002-09-01
期刊：
影响因子：
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通讯作者：
Käyhty, H
中科院分区：
文献类型：
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作者：
Soininen, A;Karpala, M;Käyhty, H
肺炎球菌荚膜多糖(PNC PSS)抗体的酶免疫分析(EIA)在某些情况下检测到在不同PNC PSS中发生交叉反应的抗体。最近，有人建议，对于只检测血清型特异性抗体，EIA可以通过用不相关的PS(如22F PS)吸收来去除交叉反应抗体来改进。吞噬细胞实验在体外测量抗体的功能活性，该实验的结果与体内保护的相关性比EIA测量抗体浓度的结果更好。我们比较了这些不同的方法来检测1,613，11A，14，19F和23F PNC PSS的抗体，这些未免疫的幼儿在2-24个月大的时候被监测了肺炎球菌携带者，急性中耳炎和PNC PSS抗体的获得。带有抗体的血清样本在接触含有特定抗体的同源血清型肺炎球菌后增加，通常具有吞噬细胞活性(OPA)(46例中的20例)。在抗体升高的样本中，来自没有接触过同种血清型肺炎球菌的儿童，常规EIA发现的特异性抗体通常是交叉反应的，很少出现OPA(68例中的10例)。将22F PS吸附用于EIA，消除了大部分假抗体增加，但仍可检测到大部分真抗体增加，并改善了EIA检测的抗体浓度与OPA之间的相关性。然而，OPA的频率在不同的血清型中存在差异。应鼓励在EIA中使用异源PS的吸收，并应进一步评估和提高EIA的特异性和吞噬细胞分析的灵敏度。
An enzyme immunoassay (EIA) for antibodies to pneumococcal capsular polysaccharides (Pnc PSs) detects in some cases antibodies that are cross-reactive within different Pnc PSs. Recently, it has been suggested that for detection of only serotype-specific antibodies, EIA can be modified by removing cross-reactive antibodies by absorption with an irrelevant PS, e.g., the type 22F PS. The opsonophagocytosis assay measures the functional activities of antibodies in vitro, and the results of that assay correlate with in vivo protection better than measurement of the antibody concentration by EIA. We compared these different methods for measuring antibodies to type 1, 613, 11A, 14, 19F, and 23F Pnc PSs in the sera of unimmunized young children who had been monitored for pneumococcal carriage, acute otitis media, and acquisition of antibodies to Pnc PSs from 2 to 24 months of age. Serum samples with antibody increases after contact with a pneumococcus of a homologous serotype contained specific antibodies and often had opsonophagocytic activity (OPA) (20 of 46). In samples with antibody increases from children who had not had contact with a pneumococcus of a homologous serotype, the antibodies found to be type specific by conventional EIA were usually cross-reactive and infrequently had OPA (10 of 68). When type 22F PS absorption was used in the EIA, most of the false antibody increases were eliminated, but most of the true antibody increases were still detected and the association between the antibody concentration detected by EIA and OPA was improved. However, there were serotype-dependent differences in the frequency of OPA. Use of absorption with a heterologous PS in EIA should be encouraged, and both the specificity of EIA and the sensitivity of opsonophagocytic assays should be further evaluated and improved.