Institute for Clinical Chemistry and Pathobiochemistry, Department for Diagnostic Laboratory Medicine, University Hospital Tübingen, Tübingen, Germany.
Institute of Medical Virology, Department for Diagnostic Laboratory Medicine, University Hospital Tübingen, Tübingen, Germany.
Clin Chem Lab Med. 2022 Jun 14;60(9):1478-1485. doi: 10.1515/cclm-2022-0360. Print 2022 Aug 26.
Antigen tests are an essential part of SARS-CoV-2 testing strategies. Rapid antigen tests are easy to use but less sensitive compared to nucleic acid amplification tests (NAT) and less suitable for large-scale testing. In contrast, laboratory-based antigen tests are suitable for high-throughput immunoanalyzers. Here we evaluated the diagnostic performance of the laboratory-based Siemens Healthineers SARS-CoV-2 Antigen (CoV2Ag) assay.
In a public test center, from 447 individuals anterior nasal swab specimens as well as nasopharyngeal swab specimens were collected. The nasal swab specimens were collected in sample inactivation medium and measured using the CoV2Ag assay. The nasopharyngeal swab specimens were measured by RT-PCR. Additionally, 9,046 swab specimens obtained for screening purposes in a tertiary care hospital were analyzed and positive CoV2Ag results confirmed by NAT.
In total, 234/447 (52.3%) participants of the public test center were positive for SARS-CoV-2-RNA. Viral lineage B1.1.529 was dominant during the study. Sensitivity and specificity of the CoV2Ag assay were 88.5% (95%CI: 83.7-91.9%) and 99.5% (97.4-99.9%), respectively. Sensitivity increased to 93.7% (97.4-99.9%) and 98.7% (97.4-99.9%) for swab specimens with cycle threshold values <30 and <25, respectively. Out of 9,046 CoV2Ag screening tests from hospitalized patients, 21 (0.2%) swab specimens were determined as false-positive by confirmatory NAT.
Using sample tubes containing inactivation medium the laboratory-based high-throughput CoV2Ag assay is a very specific and highly sensitive assay for detection of SARS-CoV-2 antigen in nasal swab specimens including the B1.1.529 variant. In low prevalence settings confirmation of positive CoV2Ag results by SARS-CoV-2-RNA testing is recommended.
抗原检测是 SARS-CoV-2 检测策略的重要组成部分。快速抗原检测使用方便，但与核酸扩增检测（NAT）相比敏感性较低，不太适合大规模检测。相比之下，基于实验室的抗原检测适用于高通量免疫分析仪。在此，我们评估了基于实验室的西门子 Healthineers SARS-CoV-2 抗原（CoV2Ag）检测的诊断性能。
在一个公共检测中心，从 447 名个体的前鼻拭子标本和鼻咽拭子标本中采集样本。将鼻拭子标本采集在样本灭活介质中，并使用 CoV2Ag 检测进行测量。鼻咽拭子标本通过 RT-PCR 进行测量。此外，对一家三级保健医院为筛查目的采集的 9046 个拭子标本进行了分析，并通过 NAT 对阳性 CoV2Ag 结果进行了确认。
在公共检测中心，共有 234/447（52.3%）名参与者 SARS-CoV-2-RNA 检测呈阳性。在研究期间，B1.1.529 谱系占主导地位。CoV2Ag 检测的灵敏度和特异性分别为 88.5%（95%CI：83.7-91.9%）和 99.5%（97.4-99.9%）。对于循环阈值<30 和<25 的拭子标本，灵敏度分别提高至 93.7%（97.4-99.9%）和 98.7%（97.4-99.9%）。在来自住院患者的 9046 次 CoV2Ag 筛查检测中，21（0.2%）个拭子标本经确认性 NAT 检测被确定为假阳性。
使用含有灭活介质的样本管，基于实验室的高通量 CoV2Ag 检测是一种非常特异和高度敏感的检测方法，可用于检测包括 B1.1.529 变体在内的鼻拭子标本中的 SARS-CoV-2 抗原。在低流行率环境下，建议通过 SARS-CoV-2-RNA 检测对阳性 CoV2Ag 结果进行确认。
