Immunology Center, Institute Adolfo Lutz, São Paulo 01246-902, Brazil; Program Interunits in Biotechnology, University of São Paulo, São Paulo 05508-000, Brazil.
Virology Center, Institute Adolfo Lutz, São Paulo 01246-902, Brazil; Postgraduate Program in Public Health Surveillance of the Disease Control Coordination, State Health Department, São Paulo 02146-901, Brazil.
J Immunol Methods. 2024 Jul;530:113683. doi: 10.1016/j.jim.2024.113683. Epub 2024 May 15.
The study evoluated an in-house Spike Receptor Binding Domain Enzyme-Linked Immunosorbent Assay (RBD-IgG-ELISA) for detecting SARS-CoV-2 IgG antibodies in infected and vaccinated individuals. The assay demonstrated a sensitivity of 91%, specificity of 99.25%, and accuracy of 95.13%. Precision and reproducibility were highly consistent. The RBD-IgG-ELISA was able to detect 96.25% of Polymerase chain reaction (PCR) confirmed cases for SARS-CoV-2 infection, demonstrating positive and negative predictive values of 99,18% and 91,69%, respectively. In an epidemiological survey, ELISA, lateral flow immunochromatographic assay (LFIA), and electrochemiluminescence immunoassay (ECLIA) exhibited diagnostic sensitivities of 68.29%, 63.41%, and 70.73%, respectively, along with specificities of 82.93%, 80.49%, and 80.49%, respectively. Agreement between RBD-IgG-ELISA/PCR was moderate (k index 0.512). However, good agreement between different assays (RBD-IgG-ELISA/LFIA k index 0.875, RBD-IgG-ELISA/ECLIA k index 0.901). Test performance on individuals' samples were inferior due to seroconversion time and chronicity. The IgG-RBD-ELISA assay demonstrated its effectiveness in monitoring antibody levels among healthcare professionals, revealing significant differences both before and after the administration of the third vaccine dose, with heightened protection levels observed following the third dose in five Coronavirus disease (COVID-19) vaccine regimens. In conclusion, the RBD-IgG-ELISA exhibits high reproducibility, specificity, and sensitivity, making it a suitable assay validated for serosurveillance and for obtaining information about COVID-19 infections or vaccinations.
该研究开发了一种内部的刺突受体结合域酶联免疫吸附测定法（RBD-IgG-ELISA），用于检测感染和接种个体中的 SARS-CoV-2 IgG 抗体。该测定法的灵敏度为 91%，特异性为 99.25%，准确性为 95.13%。精密度和重现性高度一致。RBD-IgG-ELISA 能够检测到 96.25%的聚合酶链反应（PCR）确诊的 SARS-CoV-2 感染病例，阳性和阴性预测值分别为 99.18%和 91.69%。在一项流行病学调查中，ELISA、侧向流动免疫层析测定法（LFIA）和电化学发光免疫测定法（ECLIA）的诊断敏感性分别为 68.29%、63.41%和 70.73%，特异性分别为 82.93%、80.49%和 80.49%。RBD-IgG-ELISA/PCR 之间的一致性为中度（k 指数 0.512）。然而，不同检测方法之间的一致性良好（RBD-IgG-ELISA/LFIA k 指数 0.875，RBD-IgG-ELISA/ECLIA k 指数 0.901）。由于血清转化时间和慢性期，个体样本的检测性能较差。IgG-RBD-ELISA 测定法在监测医护人员的抗体水平方面显示出了有效性，在接种第三剂疫苗前后均显示出了显著差异，在五种冠状病毒病（COVID-19）疫苗方案中，第三剂后观察到保护水平升高。总之，RBD-IgG-ELISA 具有高重复性、特异性和敏感性，是一种适合用于血清监测和获取 COVID-19 感染或接种信息的验证检测方法。
