Laboratory of Medical Microbiology and Virology, Vita-Salute San Raffaele University, Milan, Italy.
Laboratory Medicine Service, IRCCS San Raffaele Hospital, Milan, Italy.
J Med Virol. 2021 Apr;93(4):2160-2167. doi: 10.1002/jmv.26605. Epub 2020 Nov 1.
Plenty of serologic tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed so far, thus documenting the importance of evaluating the relevant features of the immune response to this viral agent. The performance of these assays is currently under investigation. Amongst them, LIAISON® SARS-CoV-2 S1/S2 IgG by DiaSorin and Elecsys Anti-SARS-CoV-2 cobas® by Roche are currently used by laboratory medicine hospital departments in Italy and many other countries. In the present study, we firstly compared two serologic tests on serum samples collected at two different time points from 46 laboratory-confirmed coronavirus disease-2019 (COVID-19) subjects. Secondly, 85 negative serum samples collected before the SARS-CoV-2 pandemic were analyzed. Thirdly, possible correlations between antibody levels and the resulting neutralizing activity against a clinical isolate of SARS-CoV-2 were evaluated. Results revealed that both tests are endowed with low sensitivity on the day of hospital admission, which increased to 97.8% and 100% for samples collected after 15 days for DiaSorin and Roche tests, respectively. The specificity evaluated for the two tests ranges from 96.5% to 100%, respectively. Importantly, a poor direct correlation between antibody titers and neutralizing activity levels was evidenced in the present study. These data further shed light on both potentials and possible limitations related to SARS-CoV-2 serology. In this context, great efforts are still necessary for investigating antibody kinetics to develop novel diagnostic algorithms. Moreover, further investigations on the role of neutralizing antibodies and their correlate of protection will be of paramount importance for the development of effective vaccines.
目前已经开发出许多针对严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的血清学检测方法，这充分证明了评估针对这种病毒的免疫反应相关特征的重要性。目前正在对这些检测方法的性能进行研究。其中，DiaSorin 的 LIAISON® SARS-CoV-2 S1/S2 IgG 和 Roche 的 Elecsys Anti-SARS-CoV-2 cobas® 目前被意大利和许多其他国家的医学检验科使用。在本研究中，我们首先比较了两种血清学检测方法在 46 名经实验室确诊的 2019 年冠状病毒病（COVID-19）患者的血清样本上的表现，这些样本是在两个不同的时间点采集的。其次，分析了 85 份在 SARS-CoV-2 大流行之前采集的阴性血清样本。第三，评估了抗体水平与针对 SARS-CoV-2 临床分离株的中和活性之间的可能相关性。结果表明，两种检测方法在患者入院当天的敏感性都较低，分别为 97.8%和 100%，这是在 15 天后采集的样本上得到的结果。两种检测方法的特异性分别为 96.5%至 100%。重要的是，本研究表明抗体滴度与中和活性水平之间存在较差的直接相关性。这些数据进一步揭示了 SARS-CoV-2 血清学检测的潜力和可能的局限性。在这方面，仍需要进一步努力研究抗体动力学，以开发新的诊断算法。此外，进一步研究中和抗体的作用及其保护相关性对于开发有效的疫苗将至关重要。
