Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Anal Biochem. 2023 Apr 1;666:115079. doi: 10.1016/j.ab.2023.115079. Epub 2023 Feb 7.
The coronavirus disease 2019 (COVID-19) pandemic is a serious health problem worldwide. Early virus detection is essential for disease control and management. Viral antigen detection by ELISA is a cost-effective, rapid, and accurate antigen diagnostic assay which could facilitate early viral detection.
An antigen-capture sandwich ELISA was developed using novel nucleocapsid (NP)-specific mouse monoclonal antibodies (MAbs). The clinical performance of the assay was assessed using 403 positive and 150 negative respiratory samples collected during different SARS-CoV-2 variants outbreaks in Iran.
The limit of detection of our ELISA assay was found to be 43.3 pg/ml for recombinant NP. The overall sensitivity and specificity of this assay were 70.72% (95% CI: 66.01-75.12) and 100% (95% CI: 97.57-100), respectively, regardless of Ct values and SARS-CoV-2 variants. There was no significant difference in our assay sensitivity for the detection of Omicron subvariants compared to Delta variant. Assay sensitivity for the BA.5 Omicron subvariant was calculated as 91.89% (95% CI: 85.17-96.23) for samples with Ct values < 25 and 82.70% (95% CI: 75.19-88.71) for samples with Ct values < 30.
Our newly developed ELISA method is reasonably sensitive and highly specific for detection of SARS-CoV-2 regardless of the variants and subvariants of the virus.
2019 年冠状病毒病（COVID-19）大流行是全球严重的健康问题。早期病毒检测对于疾病控制和管理至关重要。酶联免疫吸附试验（ELISA）检测病毒抗原是一种经济有效、快速、准确的抗原诊断检测方法，有助于早期病毒检测。
本研究使用新型核衣壳（NP）特异性鼠单克隆抗体（MAb）开发了抗原捕获夹心 ELISA。使用在伊朗不同 SARS-CoV-2 变体爆发期间收集的 403 份阳性和 150 份阴性呼吸道样本评估了该检测方法的临床性能。
本 ELISA 检测方法的检测限为 43.3 pg/ml 重组 NP。无论 Ct 值和 SARS-CoV-2 变体如何，该检测方法的总灵敏度和特异性分别为 70.72%（95%CI：66.01-75.12）和 100%（95%CI：97.57-100）。与 Delta 变体相比，本研究检测 Omicron 亚变体的检测方法灵敏度没有显著差异。对于 Ct 值<25 的样本，BA.5 Omicron 亚变体的检测灵敏度计算为 91.89%（95%CI：85.17-96.23），对于 Ct 值<30 的样本，检测灵敏度为 82.70%（95%CI：75.19-88.71）。
无论病毒的变体和亚变体如何，我们新开发的 ELISA 方法对于 SARS-CoV-2 的检测具有合理的灵敏度和高度特异性。
