Igawa Gene, Yamamoto Takamasa, Baba Yuna, Shinozuka Konomi, Yuri Maiko, Wakita Mitsuru, Misawa Shigeki, Miida Takashi, Ai Tomohiko, Tabe Yoko
Department of Clinical Laboratory, Juntendo University Hospital, Tokyo, Japan.
Department of Clinical Laboratory Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan.
Heliyon. 2021 Nov;7(11):e08393. doi: 10.1016/j.heliyon.2021.e08393. Epub 2021 Nov 16.
We evaluated the efficacy of the Siemens SARS-CoV-2 Total Antibody assay (CV2T) and IgG assay (CV2G) that can detect antibodies against the receptor binding domain of S antigen in patients with COVID-19 in a Tokyo metropolitan area.
Sensitivity and antibody levels were examined by CV2T and CV2G on Dimension EXL 200 using 236 serum samples obtained from 79 RT-PCR confirmed COVID-19 patients at multiple time points and were compared with disease severity by the World Health Organization criteria. The assay specificity was evaluated using samples collected before the COVID-19 pandemic.
The sensitivity of CV2T and CV2G were low (16.7-21.4%) in days 0-6 and increased to 43.8-52.5% in days 7-13 and to 80.8-90.0% in days 14-20. The seroprevalences persisted after day 21 to days past 42 regardless of disease severity. In every day grouping, mean antibody levels were higher in severe cases than in mild cases with a significant difference in days 14-20 and days 20-27. The specificity was 97.9 % (95% CI; 92.8-99.8) for CV2T and 99.0 % (95% CI; 94.6-100) for CV2G.
Our results indicate a high specificity and high sensitivity at 14 days of CV2T and CV2G as antibody detection assays.
我们评估了西门子 SARS-CoV-2 总抗体检测法（CV2T）和 IgG 检测法（CV2G）的效能，这两种检测法可检测东京都市区 COVID-19 患者中针对 S 抗原受体结合域的抗体。
使用从 79 名经逆转录聚合酶链反应（RT-PCR）确诊的 COVID-19 患者在多个时间点采集的 236 份血清样本，通过 Dimension EXL 200 上的 CV2T 和 CV2G 检测敏感性和抗体水平，并根据世界卫生组织标准与疾病严重程度进行比较。使用 COVID-19 大流行之前采集的样本评估检测特异性。
CV2T 和 CV2G 在第 0 - 6 天的敏感性较低（16.7 - 21.4%），在第 7 - 13 天增加到 43.8 - 52.5%，在第 14 - 20 天增加到 80.8 - 90.0%。无论疾病严重程度如何，血清阳性率在第 21 天后持续至第 42 天之后。在每个日期分组中，重症病例的平均抗体水平高于轻症病例，在第 14 - 20 天和第 20 - 27 天有显著差异。CV2T 的特异性为 97.9%（95%置信区间；92.8 - 99.8），CV2G 的特异性为 99.0%（95%置信区间；94.6 - 100）。
我们的结果表明，CV2T 和 CV2G 作为抗体检测方法在第 14 天具有高特异性和高敏感性。
