Department of Laboratory medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, 563000, P.R. China.
Center for Disease Control and Prevention of Daozhen, Zunyi, Guizhou, 563000, P.R. China.
BMC Infect Dis. 2020 Oct 20;20(1):779. doi: 10.1186/s12879-020-05489-3.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has become a public health emergency of international concern. SARS-CoV-2 RNA detection is the diagnostic criterion for coronavirus disease 2019 (COVID-19). Nevertheless, RNA detection has many limitations, such as being time-consuming and cost-prohibitive, and it must be performed in specialized laboratories. Virus antibody detection is a routine method for screening for multiple viruses, but data about SARS-CoV-2 antibody detection are limited.
Throat swabs and blood were collected from 67 suspected SARS-CoV-2 infection patients at the Affiliated Hospital of Zunyi Medical University and Zunyi Fourth People's Hospital isolated observation departments. Throat swab samples were subjected to SARS-CoV-2 RNA detection by real-time PCR. Blood was used subjected to SARS-CoV-2 IgG/IgM detection by an enzyme-linked immunosorbent assay (ELISA) and gold immunochromatography assay (GICA). Blood underwent C-reactive protein detection by immunoturbidimetry, and white blood cells, neutrophil percentages and lymphocyte percentages were counted and calculated, respectively. Clinical symptoms, age and lifestyle habits (smoking and drinking) in all patients were recorded. Data were analysed using SPSS version 19. The results were confirmed by T and χ tests; correlations with detection results were analysed by kappa coefficients. Odds ratio (OR) and corrected OR values were analysed by logistic regression. P < 0.05 was considered statistically significant.
Of the 67 patients included in this study, 26 were SARS-CoV-2 RNA-positive. GICA IgM sensitivity was 50.9% (13/26), and specificity was 90.2% (37/41). ELISA IgM sensitivity was 76.9% (20/26), and specificity was 90.2% (37/41). ELISA IgG sensitivity was 76.9% (20/26), and specificity was 95.1% (39/41). The kappa coefficients between RNA detection and ELISA IgG, ELISA IgM, and GICA IgM results were 0.741 (P < 0.01), 0.681 (P < 0.01) and 0.430 (P < 0.01), respectively.
Among the candidate blood indicators, serum IgG and IgM detected by ELISA had the best consistency and validity when compared with standard RNA detection; these indicators can be used as potential preliminary screening tools to identify those who should undergo nucleic acid detection in laboratories without RNA detection abilities or as a supplement to RNA detection.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）感染已成为国际关注的公共卫生紧急事件。SARS-CoV-2 RNA 检测是 2019 年冠状病毒病（COVID-19）的诊断标准。然而，RNA 检测有许多局限性，例如耗时且成本高，并且必须在专门的实验室进行。病毒抗体检测是筛查多种病毒的常规方法，但有关 SARS-CoV-2 抗体检测的数据有限。
采集遵义医科大学附属医院和遵义市第四人民医院隔离观察科 67 例疑似 SARS-CoV-2 感染患者的咽拭子和血液。实时 PCR 检测咽拭子样本中的 SARS-CoV-2 RNA。采用酶联免疫吸附试验（ELISA）和金免疫层析试验（GICA）检测血清中的 SARS-CoV-2 IgG/IgM。采用免疫比浊法检测 C 反应蛋白，分别计数和计算白细胞、中性粒细胞百分比和淋巴细胞百分比。记录所有患者的临床症状、年龄和生活习惯（吸烟和饮酒）。采用 SPSS 19 版进行数据分析。采用 t 检验和 χ2 检验进行组间比较；采用 Kappa 系数分析与检测结果的相关性。采用 logistic 回归分析优势比（OR）和校正 OR 值。P<0.05 为差异有统计学意义。
本研究共纳入 67 例患者，其中 26 例为 SARS-CoV-2 RNA 阳性。GICA IgM 灵敏度为 50.9%（13/26），特异度为 90.2%（37/41）。ELISA IgM 灵敏度为 76.9%（20/26），特异度为 90.2%（37/41）。ELISA IgG 灵敏度为 76.9%（20/26），特异度为 95.1%（39/41）。RNA 检测与 ELISA IgG、ELISA IgM 和 GICA IgM 结果的 Kappa 系数分别为 0.741（P<0.01）、0.681（P<0.01）和 0.430（P<0.01）。
在候选血液指标中，酶联免疫吸附试验检测的血清 IgG 和 IgM 与标准 RNA 检测的一致性和有效性最佳；这些指标可作为实验室无 RNA 检测能力时进行核酸检测的潜在初步筛查工具，或作为 RNA 检测的补充。
