3种ELISA方法与微量细胞中和试验检测SARS-CoV-2抗体滴度的相关性分析

Correlation analysis between three ELISA methods and micro-cell neutralization assay for detection of SARS-CoV-2 antibody titer

目的分析不同方法检测严重急性呼吸综合征冠状病毒2(severe acute respiratory symptom coronavirus 2,SARSCoV-2)疫苗免疫后抗体滴度的相关性,为其特异性抗体检测提供方法学依据。方法采用微量细胞中和试验及3种ELISA方法(分别以S蛋白、N蛋白和灭活全病毒颗粒为抗原)检测SARS-CoV-2灭活疫苗临床试验血清样品的IgG抗体阳转率及中和抗体滴度,并进行微量细胞中和试验与3种ELISA方法的相关性分析。结果中和抗体、S抗体、N抗体和全病毒抗体检测所得抗体阳转率分别为84.3%、91.3%、65.2%和46.6%,抗体几何平均滴度分别为16.6、945.9、72.7和18.8。3种ELISA方法(分别以S蛋白、N蛋白和灭活全病毒颗粒为抗原)与微量细胞中和试验检测结果的相关系数(r)分别为0.494、0.371和0.181。结论检测SARS-CoV-2 S抗体水平能在很大程度上反映以抗体水平升高为特征的体液免疫反应的激活情况。

Objective To analyze the correlation of different methods for the detection of antibody titer after immunization with severe acute respiratory symptom coronavirus 2(SARS-CoV-2)vaccine,and provide a methodological basis for the specific antibody detection.Methods The seroconversion rate of IgG antibody and neutralizing antibody titer of SARS-CoV-2 inactivated vaccine clinical trial serum samples were detected by micro-cell neutralization assay and three ELISA methods(using S protein,N protein and inactivated whole virus particles as antigens respectively),and the correlation among the methods was analyzed.Results The seroconversion rates detected by neutralizing antibody,S antibody,N antibody and whole virus antibody were 84.3%,91.3%,65.2%and 46.6%,and the geometric mean titers were 16.6,945.9,72.7 and 18.8,respectively.The correlation coefficients(r)between the results of three ELISA methods(using S protein,N protein and inactivated whole virus particles as antigens)and micro-cell neutralization assay were 0.494,0.371 and 0.181 respectively.Conclusion Detection of SARS-CoV-2 S antibody level reflected the activation of the humoral immune response characterized by elevated antibody level to a great extent.