Department of Laboratory Medicine, Branch of National Clinical Research Center for Laboratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
Branch of National Clinical Research Center for Laboratory Medicine, Nanjing 210029, China.
Int J Clin Pract. 2022 Aug 10;2022:5097189. doi: 10.1155/2022/5097189. eCollection 2022.
Early and rapid diagnosis is crucial in HIV preventing and treatment. However, the false-positive rate (FPR) by 4-th generation detection assays was high in low-HIV-prevalence regions.
To analyze the relation between sample-to-cutoff index (COI) and HIV confirmatory results, and to explore a new COI threshold in our own laboratory to predict HIV infection.
We retrospectively analyzed primarily reactive results by Elecsys® HIV combi PT assays and their confirmatory results by western blot (WB) at Nanjing Center for Disease Control and Prevention (CDC). The mean COI values of true positive (TP), false positive (FP), and indeterminate groups were compared, and receiver operating characteristic curve (ROC) analysis was performed to determine the optimal COI value for predicting HIV infection.
Totally 150,980 HIV serological results were reviewed, and 305 (0.2%) were primarily reactive. There are 82 (26.89%) true positives, 210 (71.92%) false positives, and 11 indeterminate samples confirmed by WB tests, and another 2 patients rejected WB tests. Mean COI values of TP (643.5) were greatly higher than that of FP (3.174) ( < 0.0001), but there is no significant difference between FP and indeterminate groups. Combining the requirement of HIV diagnosis and ROC analysis, 9.87 was established as the optimal threshold to predict the infection, with 100% sensitivity and 99.99% specificity.
By adjusting the COI threshold, the FP samples can be reduced and the efficiency of screening assays can be increased, which can save much additional reagent and staff costs and much time for delivery of HIV test results.
早期和快速诊断在 HIV 预防和治疗中至关重要。然而，在低 HIV 流行地区，第四代检测方法的假阳性率（FPR）较高。
分析样本与临界值指数（COI）与 HIV 确证结果的关系，并探索本实验室预测 HIV 感染的新 COI 阈值。
我们回顾性分析了南京疾病预防控制中心（CDC） Elecsys® HIV combi PT 检测的初筛阳性结果及其确证结果。比较了真阳性（TP）、假阳性（FP）和不确定组的平均 COI 值，并进行了受试者工作特征曲线（ROC）分析，以确定预测 HIV 感染的最佳 COI 值。
共回顾了 150980 例 HIV 血清学结果，其中 305 例（0.2%）初筛阳性。WB 确证试验中 82 例（26.89%）为真阳性，210 例（71.92%）为假阳性，11 例为不确定样本，另有 2 例患者拒绝 WB 试验。TP 的平均 COI 值（643.5）显著高于 FP（3.174）（<0.0001），但 FP 与不确定组之间无显著差异。结合 HIV 诊断要求和 ROC 分析，将 9.87 确定为预测感染的最佳阈值，具有 100%的敏感性和 99.99%的特异性。
通过调整 COI 阈值，可以减少 FP 样本，提高筛查检测的效率，从而节省大量额外的试剂和人员成本，以及大量 HIV 检测结果的交付时间。
