Deng Qiaoling, Ye Guangming, Pan Yunbao, Xie Wen, Yang Gui, Li Zhiqiang, Li Yirong
Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China.
Department of Neurosurgery, Zhongnan Hospital, Wuhan University, Wuhan, China.
Front Med (Lausanne). 2021 Jul 14;8:676560. doi: 10.3389/fmed.2021.676560. eCollection 2021.
COVID-19 emerged and rapidly spread throughout the world. Testing strategies focussing on patients with COVID-19 require assays that are high-throughput, low-risk of infection, and with small sample volumes. Antigen surveillance can be used to identify exposure to pathogens and measure acute infections. A total of 914 serum samples, collected from 309 currently infected COVID-19 patients, 48 recovered ones, and 410 non-COVID-19 patients, were used to measure N protein antigen levels by a chemilumineseent immunoassay. Diagnostic performances were analyzed in different periods after onset. There was a high level of N protein antigen in COVID-19 patients (0.56 COI), comparing to the recovered patients (0.12 COI) and controls (0.19 COI). In receiver-operating characteristic curve analysis, the area under the curve of serum N protein antigen was 0.911 in the first week after onset. In this period, Sensitivity and specificity of serologic protein antigen testing was 76.27 and 98.78%. Diagnosis performance of specific antibodies became better from the third week after onset. Subgroup analysis suggested that severe patients had higher levels of antigens than mild patients. High level of serum antigen suggested early infection and serious illness. Serum N protein antigen testing by chemiluminescence immunoassay is considered as a viable assay used to improve diagnostic sensitivity for current patients.
新型冠状病毒肺炎（COVID-19）出现并迅速在全球传播。针对COVID-19患者的检测策略需要高通量、低感染风险且样本量小的检测方法。抗原监测可用于识别病原体暴露情况并检测急性感染。本研究共收集了914份血清样本，这些样本来自309例现症COVID-19患者、48例康复患者和410例非COVID-19患者，采用化学发光免疫分析法检测N蛋白抗原水平。分析发病后不同时期的诊断性能。与康复患者（0.12 COI）和对照组（0.19 COI）相比，COVID-19患者的N蛋白抗原水平较高（0.56 COI）。在受试者工作特征曲线分析中，发病后第一周血清N蛋白抗原的曲线下面积为0.911。在此期间，血清学蛋白抗原检测的敏感性和特异性分别为76.27%和98.78%。发病后第三周特异性抗体的诊断性能有所改善。亚组分析表明，重症患者的抗原水平高于轻症患者。血清抗原水平高提示早期感染和病情严重。化学发光免疫分析法检测血清N蛋白抗原被认为是一种可行的检测方法，可提高现症患者的诊断敏感性。
