Physikalisch-Technische Bundesanstalt, Department 8.3 - Biomedical Optics Abbestr. 2-12, D-10587, Berlin, Germany.
INSTAND e.V, Society for Promoting Quality Assurance in Medical Laboratories, Duesseldorf, North Rhine-Westphalia, Germany.
BMC Res Notes. 2023 Sep 11;16(1):210. doi: 10.1186/s13104-023-06497-7.
In routine clinical laboratories, severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection is determined by reverse-transcription PCR (RT-PCR). In the COVID pandemic, a wide range of antigen detection tests were also in high demand. We investigated the correlation between SARS-CoV-2 NCap antigen and N gene concentration by analyzing samples from several INSTAND external quality assessment (EQA) schemes starting in March 2021. The absolute N gene concentration was measured using reverse transcriptase digital PCR (RT-dPCR) as reference value. Moreover, the performance of five commercial ELISA tests using an EQA inactivated SARS-CoV-2 sample at different concentrations was assessed on the basis of these reference values.
Quantitative ELISA and RT-dPCR results showed a good correlation between SARS-CoV-2 NCap antigen and RNA concentration, but this correlation varies among SARS-CoV-2 isolates. A direct correlation between SARS-CoV-2 NCap antigen concentration and genome concentration should not be generally assumed.
Further correlation studies between SARS-CoV-2 RNA and NCap antigen concentrations are needed, particularly in clinical samples and for emerging SARS-CoV-2 variants, to support the monitoring and improvement of antigen testing.
在常规临床实验室中，通过逆转录聚合酶链反应（RT-PCR）来确定严重急性呼吸综合征冠状病毒（SARS-CoV-2）感染。在 COVID 大流行期间，抗原检测也有很高的需求。我们通过分析从 2021 年 3 月开始的多个 INSTAND 外部质量评估（EQA）计划的样本，研究了 SARS-CoV-2 NCap 抗原和 N 基因浓度之间的相关性。使用逆转录数字 PCR（RT-dPCR）作为参考值来测量绝对 N 基因浓度。此外，还根据这些参考值评估了五种商业 ELISA 测试在不同浓度的灭活 SARS-CoV-2 样本上的性能。
定量 ELISA 和 RT-dPCR 结果表明 SARS-CoV-2 NCap 抗原和 RNA 浓度之间存在良好的相关性，但这种相关性在不同的 SARS-CoV-2 分离株之间存在差异。不应普遍假定 SARS-CoV-2 NCap 抗原浓度与基因组浓度之间存在直接相关性。
需要进一步研究 SARS-CoV-2 RNA 和 NCap 抗原浓度之间的相关性，特别是在临床样本和新兴的 SARS-CoV-2 变体中，以支持抗原检测的监测和改进。
