Laboratory for Viruses and Molecular Biology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel; Crusaid Kobler AIDS Center, Tel-Aviv Sourasky Medical Center, Tel-Aviv Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
Department of Tuberculosis and AIDS, Israel Ministry of Health, Jerusalem, Israel; Braun School of Public Health and Community Medicine, Faculty of Medicine, Hebrew University-Hadassah, Jerusalem, Israel.
J Clin Virol. 2018 Sep;106:18-22. doi: 10.1016/j.jcv.2018.06.017. Epub 2018 Jul 9.
Fourth-generation immunoassays used for HIV screening, simultaneously detect anti-HIV antibodies and HIV-1 P24 antigen, but are prone to false-positive results. Usually, they are followed by highly specific third-generation assay, able to differentiate between HIV-1/2 infections. In Israel, screening algorithm is based on consecutive testing by two fourth-generation assays and confirmation by a third-generation test.
To evaluate the performance of this algorithm.
Architect HIV1/2 Combo (Combo) reactive results were tested by Vidas HIV Duo Ultra (VD). Confirmation was by INNO-LIA HIV 1/2 or Geenius assays. Five-year results were retrospectively analyzed. HIV true positives (TPs), acute infected (AI), false-positives (FPs) and HIV negatives, were as defined by the algorithm.
501,338 individuals were screened, of which 956 were TPs, 64 AI and 30 F Ps. Specificity was almost 100% and positive predictive value 97%. VD was negative in 94% of confirmed Combo false-reactive individuals. The Combo results in the first tested sample differed substantially between TPs, AI and FPs, enabling the determination of a cutoff value that distinguished 94% of TPs and AI from FPs.
An algorithm is suggested that will use a single sample collection. HIV negative diagnosis will be based on Combo unreactive or Combo reactive/VD negative results. HIV positive diagnosis will be based on Combo reactive/ VD positive results, given a Combo value above a designated cutoff. Below this cutoff samples will be tested by a molecular assay. Since HIV-2 rarely occurs in Israel, the use of a third-generation confirmation assay should be discussed.
第四代免疫分析用于 HIV 筛查，可同时检测抗 HIV 抗体和 HIV-1 P24 抗原，但容易出现假阳性结果。通常，它们后面会跟着高度特异性的第三代检测方法，能够区分 HIV-1/2 感染。在以色列，筛查算法基于两种第四代检测方法的连续检测，以及第三代检测方法的确认。
评估该算法的性能。
Architect HIV1/2 Combo（Combo）阳性结果由 Vidas HIV Duo Ultra（VD）检测。确认方法是通过 INNO-LIA HIV 1/2 或 Geenius 检测。回顾性分析了五年的结果。HIV 阳性（TP）、急性感染（AI）、假阳性（FP）和 HIV 阴性按照算法定义。
共筛查了 501338 人，其中 956 人为 TP，64 人为 AI，30 人为 FP。特异性接近 100%，阳性预测值为 97%。在确认的 Combo 假阳性个体中，VD 阴性率为 94%。TP、AI 和 FP 之间的首次检测样本的 Combo 结果差异很大，这使得确定一个可以区分 94%的 TP 和 AI 与 FP 的截止值成为可能。
建议使用单个样本采集的算法。HIV 阴性诊断将基于 Combo 无反应或 Combo 反应/VD 阴性结果。HIV 阳性诊断将基于 Combo 反应/VD 阳性结果，前提是 Combo 值超过指定的截止值。低于此截止值的样本将通过分子检测进行检测。由于 HIV-2 在以色列很少发生，因此应讨论使用第三代确认检测方法。
