Institute of Laboratory Medicine, University Hospital, LMU Munich, Munich, Germany.
PLoS One. 2021 May 13;16(5):e0251587. doi: 10.1371/journal.pone.0251587. eCollection 2021.
During the COVID-19 pandemic, SARS-CoV-2 antibody testing has been suggested for (1) screening populations for disease prevalence, (2) diagnostics, and (3) guiding therapeutic applications. Here, we conducted a detailed clinical evaluation of four Anti-SARS-CoV-2 immunoassays in samples from acutely ill COVID-19 patients and in two negative cohorts.
443 serum specimens from serial sampling of 29 COVID-19 patients were used to determine clinical sensitivities. Patients were stratified for the presence of acute respiratory distress syndrome (ARDS). Individual serum specimens from a pre-COVID-19 cohort of 238 healthy subjects and from a PCR-negative clinical cohort of 257 patients were used to determine clinical specificities. All samples were measured side-by-side with the Anti-SARS-CoV-2-ELISA (IgG), Anti-SARS-CoV-2-ELISA (IgA) and Anti-SARS-CoV-2-NCP-ELISA (IgG) (Euroimmun AG, Lübeck, Germany) and the Elecsys Anti-SARS-CoV-2 ECLIA (Roche Diagnostics International, Rotkreuz, Switzerland).
Median seroconversion occurred earlier in ARDS patients (8-9 days) than in non-ARDS patients (11-17 days), except for EUR N-IgG. Rates of positivity and mean signal ratios in the ARDS group were significantly higher than in the non-ARDS group. Sensitivities between the four tested immunoassays were equivalent. In the set of negative samples, the specificity of the Anti-SARS-CoV-2-ELISA (IgA) was lower (93.9%) compared to all other assays (≥98.8%) and the specificity of Anti-SARS-CoV-2-NCP-ELISA (IgG) was lower (98.8%) than that of Elecsys Anti-SARS-CoV-2 (100%).
Serial sampling in COVID-19 patients revealed earlier seroconversion and higher signal ratios of SARS-CoV-2 antibodies as a potential risk marker for the development of ARDS, suggesting a utility for antibody testing in acutely diseased patients.
在 COVID-19 大流行期间，SARS-CoV-2 抗体检测被建议用于（1）筛查疾病流行率，（2）诊断，和（3）指导治疗应用。在这里，我们对来自急性 COVID-19 患者的样本和两个阴性队列中的四种抗 SARS-CoV-2 免疫测定进行了详细的临床评估。
使用 29 例 COVID-19 患者的系列采样的 443 份血清标本来确定临床敏感性。患者分为急性呼吸窘迫综合征（ARDS）的存在分层。来自 238 例健康受试者的 COVID-19 前队列的个体血清标本和来自 257 例 PCR 阴性临床队列的个体血清标本用于确定临床特异性。所有样本均与 Anti-SARS-CoV-2-ELISA（IgG）、Anti-SARS-CoV-2-ELISA（IgA）和 Anti-SARS-CoV-2-NCP-ELISA（IgG）（Euroimmun AG，吕贝克，德国）和 Elecsys Anti-SARS-CoV-2 ECLIA（罗氏诊断国际，罗特克吕茨，瑞士）并排测量。
ARDS 患者的中位血清转换时间早于非 ARDS 患者（8-9 天），但 EUR N-IgG 除外。ARDS 组的阳性率和平均信号比值均显著高于非 ARDS 组。四种测试免疫测定的敏感性相当。在阴性样本组中，Anti-SARS-CoV-2-ELISA（IgA）的特异性（93.9%）低于所有其他测定（≥98.8%），Anti-SARS-CoV-2-NCP-ELISA（IgG）的特异性（98.8%）低于 Elecsys Anti-SARS-CoV-2（100%）。
在 COVID-19 患者中进行的系列采样显示，SARS-CoV-2 抗体的血清转换更早，信号比值更高，这可能是 ARDS 发展的风险标志物，表明抗体检测在急性疾病患者中的有用性。
