Data from: Development of an international external quality assurance program for HIV-1 incidence using the Limiting Antigen Avidity assay

Laboratory assays for identifying recent HIV-1 infections are widely used for estimating incidence in cross-sectional population-level surveys in global HIV-1 surveillance. Adequate assay and laboratory performance are required to ensure accurate incidence estimates. The NIAID-supported External Quality Assurance Program Oversight Laboratory (EQAPOL) established a proficiency testing program for the most widely-used incidence assay, the HIV-1 Limiting Antigen Avidity EIA (LAg), with US Centers for Disease Control and Prevention (CDC)-approved kits manufactured by Sedia Biosciences Corporation and Maxim Biomedical. The objective of this program is to monitor the performance of participating laboratories. Four rounds of blinded external proficiency (EP) panels were distributed to up to twenty testing sites (7 North American, 5 African, 4 Asian, 2 South American and 2 European).
These panels consisted of ten plasma samples: three blinded well-characterized HIV-1-seropositive samples that were included as replicates and an HIV-negative control. The seropositive samples spanned the dynamic range of the assay and are categorized as either recent or long-term infection. Participating sites performed the assay according to manufacturers’ instructions and completed an online survey to gather information on kit manufacturer, lot of kit used, laboratory procedures and the experience of technicians. On average, fifteen sites participated in each round of testing, with an average of four sites testing with only the Maxim assay, seven testing with only the Sedia assay and five sites utilizing both assays. Overall, the Sedia and Maxim assays yielded similar infection status categorization across the laboratories; however, for most of the nine HIV+ samples tested, there were significant differences in the optical density readouts, ODn (N=8) and OD (N=7), between LAg kit manufacturers (p < 0.05 based on mixed effects models. The EQAPOL LAg program is important for monitoring laboratory performance as well as detecting variations between manufacturers of HIV-1 incidence assays.

用于识别近期HIV-1感染的实验室检测方法，在全球HIV-1监测的横断面人群水平调查中被广泛用于估算感染发生率。为确保感染发生率估算的准确性，需保证检测方法及实验室操作具备足够性能。由美国国家过敏和传染病研究所（National Institute of Allergy and Infectious Diseases, NIAID）资助的外部质量保证项目监督实验室（External Quality Assurance Program Oversight Laboratory, EQAPOL），针对目前应用最广泛的HIV-1感染发生率检测方法——HIV-1限制性抗原亲和力酶联免疫吸附试验（HIV-1 Limiting Antigen Avidity EIA, LAg），建立了能力验证项目，所用试剂盒由赛迪亚生物科学公司（Sedia Biosciences Corporation）和马克西姆生物医学公司（Maxim Biomedical）生产，且获得美国疾病控制与预防中心（Centers for Disease Control and Prevention, CDC）认证。本项目的目标是对参与实验室的检测性能进行监测。项目共向最多20家检测机构（其中北美7家、非洲5家、亚洲4家、南美2家及欧洲2家）发放了4轮盲态外部能力验证（EP）样本组。
每轮样本组包含10份血浆样本：3份盲态且经过充分表征的HIV-1血清阳性重复样本，以及1份HIV阴性对照。血清阳性样本覆盖了该检测方法的动态检测范围，被划分为近期感染或长期感染两类。参与机构需按照试剂盒制造商的说明书开展检测，并完成线上调查问卷，以收集试剂盒制造商、使用的试剂盒批号、实验室操作流程以及技术人员经验等信息。
每轮检测平均有15家机构参与，其中平均4家机构仅使用马克西姆试剂盒开展检测，7家仅使用赛迪亚试剂盒，5家同时使用两种试剂盒。整体而言，赛迪亚与马克西姆试剂盒在各实验室的感染状态分类结果较为相似；但针对检测的9份HIV阳性样本中的大多数，两种LAg试剂盒的光密度读数（ODn（N=8）与OD（N=7））存在显著差异（基于混合效应模型，p<0.05）。EQAPOL的LAg项目对于监测实验室检测性能，以及识别HIV-1感染发生率检测试剂盒制造商间的差异具有重要意义。