Gillot Constant, Douxfils Jonathan, Cadrobbi Julie, Laffineur Kim, Dogné Jean-Michel, Elsen Marc, Eucher Christine, Melchionda Sabrina, Modaffarri Élise, Tré-Hardy Marie, Favresse Julien
Department of Pharmacy, Namur Research Institute for Life Sciences, University of Namur, B-5000 Namur, Belgium.
Central Laboratory Department, Qualiblood sa, 5000 Namur, Belgium.
J Clin Med. 2020 Nov 21;9(11):3752. doi: 10.3390/jcm9113752.
Strategies to detect SARS-CoV-2 are increasingly being developed. Among them, serological methods have been developed. Nevertheless, although these may present an interesting clinical performance, they are often directed against only one antigen. This study aims at evaluating the clinical performance of an innovative multiplex immunoassay (i.e., CoViDiag assay) detecting simultaneously the presence of antibodies directed against N, S1, S2, RBD and NTD antigens. Sensitivity was evaluated in 135 samples obtained from 94 rRT-PCR confirmed coronavirus disease 2019 (COVID-19) patients. Non-SARS-CoV-2 sera ( = 132) collected before the COVID-19 pandemic with potential cross-reactions to the SARS-CoV-2 immunoassay were included in the specificity analysis. The antibody signature was also studied in hospitalized and non-hospitalized patients. The specificity of the CoViDiag assay was excellent for all antibodies (99.2 to 100%) using adapted cut-offs. None of the false positive samples were positive for more than one antibody. The sensitivity obtained from samples collected 14 days since symptom onset varied from 92.0 to 100.0% depending on the antibody considered. Among samples collected more than 14 days after symptom onset, 12.8, 66.3, 3.5, 9.3, 5.8 and 2.3% were positive for 5, 4, 3, 2, 1 or 0 antibodies, respectively. A trend toward higher antibody titers was observed in hospitalized patient in the early days since symptom onset. However, no significant difference was observed compared to non-hospitalized patients after 14 days since symptom onset. The clinical performance of the CoViDiag 5 IgG assay is sufficient to recommend its use for the detection and the characterization of the antibody signature following SARS-CoV-2 infection. The combination of several antigens in the same test improves the overall specificity and sensitivity of the test. Further research is needed to investigate whether this strategy may be of interest to identify severe disease outcome in patients with SARS-CoV-2 infection.
检测严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的策略正在不断发展。其中，血清学方法已经得到开发。然而，尽管这些方法可能具有有趣的临床性能，但它们通常仅针对一种抗原。本研究旨在评估一种创新的多重免疫分析方法（即CoViDiag分析）的临床性能，该方法可同时检测针对N、S1、S2、受体结合域（RBD）和N端结构域（NTD）抗原的抗体的存在情况。在从94例逆转录聚合酶链反应（rRT-PCR）确诊的2019冠状病毒病（COVID-19）患者中获取的135份样本中评估了敏感性。特异性分析纳入了在COVID-19大流行之前收集的、对SARS-CoV-2免疫分析可能存在交叉反应的非SARS-CoV-2血清（n = 132）。还对住院患者和非住院患者的抗体特征进行了研究。使用调整后的临界值，CoViDiag分析对所有抗体的特异性都非常出色（99.2%至100%）。没有假阳性样本对一种以上抗体呈阳性。根据所考虑的抗体不同，自症状出现14天以来收集的样本的敏感性在92.0%至100.0%之间变化。在症状出现14天之后收集的样本中，分别有12.8%、66.3%、3.5%、9.3%、5.8%和2.3%的样本对5、4、3、2、1或0种抗体呈阳性。在症状出现后的早期，住院患者中观察到抗体滴度有升高趋势。然而，在症状出现14天后，与非住院患者相比没有观察到显著差异。CoViDiag 5 IgG分析的临床性能足以推荐将其用于SARS-CoV-2感染后抗体特征的检测和表征。同一检测中多种抗原的组合提高了检测的总体特异性和敏感性。需要进一步研究来调查这种策略对于识别SARS-CoV-2感染患者的严重疾病结局是否有意义。
