用基于重组抗原的捕获酶联免疫试验检测HIV-1新发感染

Detection of recent HIV-1 infection using a recombinant antigen-based capture enzyme immunoassay

目的探讨基于重组抗原的捕获酶联免疫试验(RCEIA)检测HIV-1新发感染的可行性。方法使用来自队列研究的HIV-1抗体阳转系列样品,包括来自40名HIV-1感染者的140份血浆样品,用RCEIA试验检测,获得吸光度(OD)值和标准化吸光度(ODn)值。作折线图观察ODn值与阳转时间的关系;用SPSS 22.0软件作ROC曲线,获得RCEIA试验的临界值(cutoff值)与平均新发感染期(MDRI);作散点图比较RCEIA试验与BED HIV-1捕获酶联免疫试验(BED试验)检测结果的相关性。结果14板RCEIA试验的检测结果显示,校准品和3份阳性对照OD值的变异系数为7.0%~8.9%,阳性对照ODn值的变异系数为3.1%~7.7%。针对HIV-1阳转系列样品,反映特异性IgG占总IgG比例的RCEIA试验的ODn值随阳转时间的推移呈上升趋势,但存在个体差异。初步得到RCEIA试验的最佳cutoff值为0.8,平均新发感染期为197天,假新发感染比例与BED试验的差异无统计学意义(P=1.000)。RCEIA试验与BED试验检测结果ODn值的相关性较好(r=0.907)。结论基于重组抗原的RCEIA操作稳定性好,可以在群体水平区分HIV-1新发感染与长期感染,其最佳cutoff值及用于HIV-1新发感染率估算的技术参数(平均新发感染期和假新发感染率)有待通过增加样品量进一步测算。

Objective To explore the feasibility of detecting recent human immunodeficiency virus type-1(HIV-1 infection)using a recombinant antigen-based capture enzyme immunoassay(RCEIA).Methods A total of 140 longitudinal plasma specimens collected from 40 HIV-1 seroconverting individuals from 2 cohorts were used in this study.RCEIA detected these specimens to obtain optical density(OD)values and normalized optical density(ODn)values.The ODn values were plotted against the estimated days post-seroconversion.Statistical Program for Social Sciences(SPSS,version 22.0)was used to obtain a certain threshold(cutoff)value and mean duration of recent infection(MDRI)for RCEIA.The relevance between the ODn values of RCEIA and BED HIV-1 capture enzyme immunoassay(BED EIA)was analyzed by scatterplot.Results Coefficient of variation for one calibrator specimen and three positive controls was 7.0%-8.9%for raw OD values.The coefficient of variation for the positive controls was 3.1%-7.7%for ODn values from 14 plate runs.The ratio of HIV-specific IgG to total IgG,as measured by RCEIA,increased in almost all individuals over time.While there was heterogeneity of kinetics among individual responses.Limited data showed that the optimal cutoff was ODn of 0.8.The MDRI was 197 days for RCEIA,and the difference between the proportion false recent for RCEIA and that for BED EIA was not statistically significant(p=1.000).Also,the ODn values of RCEIA correlated well with those of BED EIA(r=0.907).Conclusion With the feature of good stability,the recombinant antigen-based capture enzyme immunoassay(RCEIA)offers an approach to detect recent HIV-1 infection at the population level.A larger sample size is needed to calculate the optimal cutoff value and parameters(MDRI and current false rate)in estimating HIV-1 incidence.