Moscato Giovanna, Mazzetti Paola, Lucenteforte Ersilia, Rosellini Alfredo, Cara Alice, Quaranta Paola, Mainardi Valerio, Villa Pietro, Focosi Daniele, Lanza Maria, Bianco Irene, Mazzoni Alessandro, Falcone Marco, Menichetti Francesco, Maggi Fabrizio, Lai Michele, Freer Giulia, Pistello Mauro
Seroimmunology Unit, Pisa University Hospital, Pisa, Italy.
Virology Unit, Pisa University Hospital, Pisa, Italy.
J Clin Virol Plus. 2021 Jun;1(1):100016. doi: 10.1016/j.jcvp.2021.100016. Epub 2021 May 4.
COVID19 convalescent patient plasma units with high titer neutralizing antibody can be used to treat patients with severe disease. Therefore, in order to select suitable donors, neutralizing antibody titer against SARS CoV-2 needs to be determined. Because the neutralization assay is highly demanding from several points of view, a pre-selection of sera would be desirable to minimize the number of sera to be tested. In this study, a total of 140 serum samples that had been titrated for SARS-CoV-2 neutralizing antibody by microneutralization assay were also tested for the presence of anti-SARS-CoV2 antibody using 5 different tests: Architect® immunoassay (Abbott Diagnostics), detecting IgG against the nucleocapsid protein, LIAISON XL® (Diasorin) detecting IgG against a recombinant form of the S1/S2 subunits of the spike protein, VITROS® (Ortho Clinical Diagnostics), detecting IgG against a recombinant form of the spike protein, and ELISA (Euroimmun AG), detecting IgA or IgG against a recombinant form of the S1 subunit. To determine which immunoassay had the highest chance to detect sera with neutralizing antibodies above a certain threshold, we compared the results obtained from the five immunoassays with the titers obtained by microneutralization assay by linear regression analysis and by using receiver operating characteristic curve and Youden's index. Our results indicate that the most suitable method to predict sera with high Nab titer is Euroimmun® IgG, followed closely by Ortho VITROS® Anti-SARS-CoV-2 IgG.
具有高滴度中和抗体的新冠康复患者血浆单位可用于治疗重症患者。因此，为了选择合适的献血者，需要测定针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的中和抗体滴度。由于中和试验在多个方面要求很高，因此希望对血清进行预筛选，以尽量减少待检测血清的数量。在本研究中，共有140份通过微量中和试验滴定了SARS-CoV-2中和抗体的血清样本，还使用5种不同的检测方法检测了抗SARS-CoV-2抗体的存在：Architect®免疫分析（雅培诊断），检测针对核衣壳蛋白的IgG；LIAISON XL®（索灵），检测针对刺突蛋白重组形式的S1/S2亚基的IgG；VITROS®（奥森多临床诊断），检测针对刺突蛋白重组形式的IgG；以及酶联免疫吸附测定（欧蒙医学诊断有限公司），检测针对S1亚基重组形式的IgA或IgG。为了确定哪种免疫测定法最有可能检测出中和抗体高于某一阈值的血清，我们通过线性回归分析以及使用受试者工作特征曲线和尤登指数，将五种免疫测定法获得的结果与微量中和试验获得的滴度进行了比较。我们的结果表明，预测高滴度中和抗体血清的最合适方法是欧蒙®IgG，其次是奥森多VITROS®抗SARS-CoV-2 IgG。
