Department of Laboratory Medicine, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, People's Republic of China.
College of Laboratory Medicine, North Sichuan Medical College, Nanchong, Sichuan, People's Republic of China.
Sci Rep. 2021 Jan 13;11(1):1033. doi: 10.1038/s41598-020-80047-0.
To explore the effects of urea dissociation on reducing false-positive results of the Elecsys HIV combi PT assay. A retrospective analysis was used to evaluate the false-positive rate of the Elecsys HIV combi PT assay. Six false-positive sera, six positive sera and six sera from patients with early HIV infection were collected. Dissociation was performed using 1 mol/L, 2 mol/L, 4 mol/L, 6 mol/L, or 8 mol/L urea, and HIV screening assay were then detected to select the appropriate concentration of urea dissociation. Next, 55 false-positive sera and 15 sera from early HIV infection were used to verify the best concentration of urea to achieve dissociation. Retrospective analysis showed that the COI of the Elecsys HIV combi PT assay in false-positive sera ranged from 1.0 to 200.0, and approximately 97.01%(227/234) of false-positive sera were in the range of 1.0-15.0. The avidity index (AI) in positive and false-positive sera decreased as the urea dissociation concentration increased. When the dissociation concentration was 6 mol/L, the AI of false-positive serum was between 0.0234 and 0.2567, and the AI of early HIV infection sera was between 0.4325 and 0.5017. The difference in AI between false-positive and positive samples was significant. When negativity was defined as an AI of less than 0.3970, the sensitivity and specificity were 100.0% and 100.0%, respectively. Urea-mediated dissociation could significantly reduce the false-positive rate of the Elecsys HIV combi PT assay with a low COI. Our findings provided a reference for distinguishing positive and false-positive of the Elecsys HIV combi PT assay.
探讨尿素解离对降低 Elecsys HIV combi PT 检测假阳性结果的影响。采用回顾性分析评估 Elecsys HIV combi PT 检测的假阳性率。收集 6 份假阳性血清、6 份阳性血清和 6 份早期 HIV 感染患者血清。用 1mol/L、2mol/L、4mol/L、6mol/L 或 8mol/L 尿素进行解离，然后检测 HIV 筛选检测以选择合适的尿素解离浓度。接下来，用 55 份假阳性血清和 15 份早期 HIV 感染血清验证尿素解离的最佳浓度。回顾性分析显示，Elecsys HIV combi PT 检测在假阳性血清中的 COI 范围为 1.0 至 200.0，约 97.01%（227/234）的假阳性血清处于 1.0-15.0 范围内。阳性和假阳性血清的亲和力指数（AI）随着尿素解离浓度的增加而降低。当解离浓度为 6mol/L 时，假阳性血清的 AI 介于 0.0234 至 0.2567 之间，早期 HIV 感染血清的 AI 介于 0.4325 至 0.5017 之间。假阳性和阳性样本之间的 AI 差异有统计学意义。当将 AI 小于 0.3970 定义为阴性时，其灵敏度和特异性分别为 100.0%和 100.0%。尿素介导的解离可显著降低 Elecsys HIV combi PT 检测的低 COI 假阳性率。我们的研究结果为区分 Elecsys HIV combi PT 检测的阳性和假阳性结果提供了参考。
