Gonoshasthaya-RNA Molecular Diagnostic & Research Center, Dhanmondi, Dhaka, Bangladesh.
Department of Microbiology, Gono Bishwabidyalay, Savar, Dhaka, Bangladesh.
PLoS One. 2021 Feb 2;16(2):e0246346. doi: 10.1371/journal.pone.0246346. eCollection 2021.
In the ongoing pandemic situation of COVID-19, serological tests can complement the molecular diagnostic methods, and can be one of the important tools of sero-surveillance and vaccine evaluation.
To develop and evaluate a rapid SARS-CoV-2 specific ELISA for detection of anti-SARS-CoV2 IgG from patients' biological samples.
In order to develop this ELISA, three panels of samples (n = 184) have been used: panel 1 (n = 19) and panel 2 (n = 60) were collected from RT-PCR positive patients within 14 and after 14 days of onset of clinical symptoms, respectively; whereas panel 3 consisted of negative samples (n = 105) collected either from healthy donors or pre-pandemic dengue patients. As a capturing agent full-length SARS-CoV2 specific recombinant nucleocapsid was immobilized. Commercial SARS-CoV2 IgG kit based on chemiluminescent assay was used for the selection of samples and optimization of the assay. The threshold cut-off point, inter-assay and intra-assay variations were determined.
The incubation/reaction time was set at a total of 30 minutes with the sensitivity of 84% (95% confidence interval, CI, 60.4%, 96.6%) and 98% (95% CI, 91.1%, 100.0%), for panel 1 and 2, respectively; with overall 94.9% sensitivity (95% CI 87.5%, 98.6%). Moreover, the clinical specificity was 97.1% (95% CI, 91.9%, 99.4%) with no cross reaction with dengue samples. The overall positive and negative predictive values are 96.2% (95% CI 89.2%, 99.2%) and 96.2% (95% CI, 90.6% 99.0%), respectively. In-house ELISA demonstrated 100% positive and negative percent agreement with Elecsys Anti-SARS-CoV-2, with Cohen's kappa value of 1.00 (very strong agreement), while comparing 13 positive and 17 negative confirmed cases.
The assay is rapid and can be applied as one of the early and retrospective sero-monitoring tools in all over the affected areas.
在当前 COVID-19 大流行的情况下，血清学检测可以补充分子诊断方法，是血清学监测和疫苗评估的重要工具之一。
开发和评估一种快速的 SARS-CoV-2 特异性 ELISA 检测试剂盒，用于检测患者生物样本中的抗 SARS-CoV-2 IgG。
为了开发这种 ELISA，我们使用了三个样本组（n=184）：第 1 组（n=19）和第 2 组（n=60）分别从 RT-PCR 阳性患者发病后 14 天内和 14 天后采集；第 3 组由阴性样本组成（n=105），分别从健康供体或大流行前登革热患者中采集。全长 SARS-CoV2 特异性重组核衣壳蛋白被固定在包被板上作为捕获剂。使用商业基于化学发光的 SARS-CoV2 IgG 试剂盒进行样本选择和优化检测。确定了临界值、组内和组间变异。
反应时间设置为 30 分钟，第 1 组和第 2 组的敏感性分别为 84%（95%置信区间，60.4%，96.6%）和 98%（95%置信区间，91.1%，100.0%），总体敏感性为 94.9%（95%置信区间，87.5%，98.6%）。此外，临床特异性为 97.1%（95%置信区间，91.9%，99.4%），与登革热样本无交叉反应。总的阳性和阴性预测值分别为 96.2%（95%置信区间，89.2%，99.2%）和 96.2%（95%置信区间，90.6%，99.0%）。内部 ELISA 与 Elecsys Anti-SARS-CoV-2 的阳性和阴性符合率均为 100%，Cohen's kappa 值为 1.00（极强一致性），同时比较了 13 例阳性和 17 例阴性确诊病例。
该检测方法快速，可作为受影响地区早期和回顾性血清监测工具之一。
