Quantitative detection of increasing HIV type 1 antibodies after seroconversion: A simple assay for detecting recent HIV infection and estimating incidence
Quantitative detection of increasing HIV type 1 antibodies after seroconversion: A simple assay for detecting recent HIV infection and estimating incidence
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DOI：
10.1089/088922202753472874
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发表时间：
2002-03-01
影响因子：
1.5
通讯作者：
McDougal, JS
中科院分区：
文献类型：
--
作者：
Parekh, BS;Kennedy, MS;McDougal, JS
我们设计了一种简单的酶免疫测定 (EIA)，可检测血清转化后抗 HIV IgG 水平的增加，并可用于检测近期的 HIV-1 感染。使用包含来自 HIV-1 B、E 和 D 亚型的 gp41 免疫显性序列的分支肽，可以对不同亚型之间的 HIV 特异性抗体进行类似的检测。由于捕获 EIA 的竞争性，血清转化后 2 年内观察到 HIV-1 特异性 IgG 在总 IgG 中的比例逐渐增加。这与使用固相相同抗原的传统 EIA 获得的结果形成鲜明对比，该结果在血清转化后不久就达到稳定水平。该测定用于测试来自美国（B 亚型）和泰国（B 亚型和 E 亚型）139 起事件感染的 622 份纵向样本。该测定还进行了额外的 8 M 尿素孵育步骤，以评估高亲和力抗体的贡献。使用校准样本计算归一化光密度（OD-n）（OD样本/OD校准样本）。增量分析表明，1.0 OD-n 的截止值和 160 天的血清转换期为分类事件或长期感染提供了敏感性和特异性的最佳组合。尿素步骤将血清转化期延长至 180 天，且具有相似的敏感性和特异性。对 B 和 E 亚型标本的单独分析得出相同的最佳 OD-n 阈值和相似的血清转换期。该测定在非洲样本（A、C 和 D 亚型）中得到了进一步验证，其中观察到的发生率在预期发生率的 10% 以内。该测定对于检测最近的 HIV-1 感染和估计全球不同 HIV-1 亚型的发病率应该很有用。
We have devised a simple enzyme immunoassay (EIA) that detects increasing levels of anti-HIV IgG after seroconversion and can be used for detecting recent HIV-1 infection. Use of a branched peptide that included gp41 immunodominant sequences from HIV-1 subtypes B, E, and D allowed similar detection of HIV-specific antibodies among various subtypes. Because of the competitive nature of the capture EIA, a gradual increase in the proportion of HIV-1-specific IgG in total IgG was observed for 2 years after seroconversion. This was in contrast to results obtained with the conventional EIA using the same antigen in solid phase, which plateaus soon after seroconversion. The assay was used to test 622 longitudinal specimens from 139 incident infections in the United States (subtype B) and in Thailand (subtypes B and E). The assay was also performed with an additional 8 M urea incubation step to assess the contribution off high-avidity antibodies. Normalized optical density (OD-n) was calculated (ODspecimen/ODcalibrator), using a calibrator specimen. An incremental analysis indicated that a cutoff of 1.0 OD-n and a seroconversion period of 160 days offered the best combination of sensitivity and specificity for classifying incident or long-term infections. The urea step increased the seroconversion period to 180 days with similar sensitivity and specificity. Separate analysis of B and E subtype specimens yielded the same optimal OD-n threshold and similar seroconversion periods. The assay was further validated in African specimens (subtypes A, C, and D) where the observed incidence was within 10% of the expected incidence. This assay should be useful for detecting recent HIV-1 infection and for estimating incidence among diverse HIV-1 subtypes worldwide.