Ibrahim Essam H, Ghramh Hamed A, Kilany Mona
Biology Department, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia.
Research Center for Advanced Materials Science (RCAMS), King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia.
J King Saud Univ Sci. 2021 Jun;33(4):101439. doi: 10.1016/j.jksus.2021.101439. Epub 2021 Apr 15.
By the end of year 2019, the new virus SARS-CoV-2 appeared, causing the Coronavirus Disease 2019 (COVID-19), and spread very fast globally. A continuing need for diagnostic tools is a must to contain its spread. Till now, the gold standard method, the reverse transcription polymerase chain reaction (RT-PCR), is the precise procedure to detect the virus. However, SARS-CoV-2 may escape RT-PCR detection for several reasons. The development of well-designed, specific and sensitive serological test like enzyme immunoassay (EIA) is needed. This EIA can stand alone or work side by side with RT-PCR. In this study, we developed several EIAs including plates that are coated with either specially designed SARS-CoV-2 nucleocapsid or surface recombinant proteins. Each protein type can separately detect anti-SARS-CoV-2 IgM or IgG antibodies. For each EIAs, the cut-off value, specificity and sensitivity were determined utilizing RT-PCR confirmed Covid-19 and pre-pandemic healthy and other viruses-infected sera. Also, the receiver operator characteristic (ROC) analysis was performed to define the specificities and sensitivities of the optimized assay. The in-house EIAs were validated by comparing against commercial EIA kits. All in-house EIAs showed high specificity (98-99%) and sensitivity (97.8-98.9%) for the detection of IgG/IgM against RBD and N proteins of SARS-CoV-2. From these results, the developed Anti-RBD and anti-N IgG and IgM antibodies EIAs can be used as a specific and sensitive tool to detect SARS-CoV-2 infection, calculate the burden of disease and case fatality rates.
到2019年底，新型冠状病毒SARS-CoV-2出现，引发了2019冠状病毒病（COVID-19），并在全球迅速传播。持续需要诊断工具来遏制其传播。到目前为止，金标准方法——逆转录聚合酶链反应（RT-PCR）是检测该病毒的精确程序。然而，SARS-CoV-2可能由于多种原因逃避RT-PCR检测。因此需要开发设计精良、特异性强且灵敏的血清学检测方法，如酶免疫测定（EIA）。这种EIA可以单独使用，也可以与RT-PCR联合使用。在本研究中，我们开发了几种EIA，包括用专门设计的SARS-CoV-2核衣壳或表面重组蛋白包被的平板。每种蛋白类型都可以分别检测抗SARS-CoV-2 IgM或IgG抗体。对于每种EIA，利用RT-PCR确诊的COVID-19以及大流行前的健康血清和其他病毒感染血清确定临界值、特异性和敏感性。此外，还进行了受试者工作特征（ROC）分析以确定优化检测方法的特异性和敏感性。通过与商业EIA试剂盒比较对内部EIA进行验证。所有内部EIA在检测针对SARS-CoV-2 RBD和N蛋白的IgG/IgM时均显示出高特异性（98 - 99%）和敏感性（97.8 - 98.9%）。根据这些结果，所开发的抗RBD和抗N IgG及IgM抗体EIA可作为检测SARS-CoV-2感染、计算疾病负担和病死率的特异性和灵敏工具。
