Yu Minghang, Chen Danying, Tang Xiaomeng, Zhang Yuanyuan, Liang Pu, Xiong Yang, Li Rui, Song Rui, Chen Xiaoyou, Zhao Xuesen, Wang Xi, Jin Ronghua
Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, P.R. China.
Beijing Institute of Infectious Diseases, Beijing, P.R. China.
Clin Chem Lab Med. 2023 Jan 19;61(6):1123-1130. doi: 10.1515/cclm-2022-1039. Print 2023 May 25.
To describe a high-sensitivity SARS-CoV-2 antigen test that is based on the fully automated light-initiated chemiluminescent immunoassay (LiCA), and to validate its analytical characteristics and clinical agreement on detecting SARS-CoV-2 infection against the reference molecular test.
Analytical performance was validated and detection limits were determined using different types of nucleocapsid protein samples. 798-pair anterior nasal swab specimens were collected from hospitalized patients and asymptomatic screening individuals. Agreement between LiCA antigen and real-time reverse transcription polymerase chain reaction (rRT-PCR) was evaluated.
Repeatability and within-lab precision were 1.6-2.3%. The C∼C interval was -5.1-4.6% away from C. Detection limits in average (SD) were 325 (±141) U/mL on the national reference panel, 0.07 (±0.04) TCID/mL on active viral cultures, 0.27 (±0.09) pg/mL on recombinant nucleocapsid proteins and 1.07 (±1.01) TCID/mL on inactivated viral suspensions, respectively. LiCA detected a median of 374-fold (IQR 137-643) lower levels of the viral antigen than comparative rapid tests. As reference to the rRT-PCR method, overall sensitivity and specificity were determined to be 97.5% (91.4-99.7%) and 99.9% (99.2-100%), respectively. Total agreement between both methods was 99.6% (98.7-99.9%) with Cohen's kappa 0.98 (0.96-1). A positive detection rate of 100% (95.4-100%) was obtained as Ct≤37.8.
The LiCA system provides an exceptionally high-sensitivity and fully automated platform for the detection of the SARS-CoV-2 antigen in nasal swabs. The assay may have high potential use for large-scale population screening and surveillance of COVID-19 as an alternative to the rRT-PCR test.
描述一种基于全自动光启动化学发光免疫分析（LiCA）的高灵敏度严重急性呼吸综合征冠状病毒2（SARS-CoV-2）抗原检测方法，并针对参考分子检测方法验证其在检测SARS-CoV-2感染方面的分析特性和临床一致性。
使用不同类型的核衣壳蛋白样本验证分析性能并确定检测限。从住院患者和无症状筛查个体中收集了798对前鼻拭子样本。评估了LiCA抗原与实时逆转录聚合酶链反应（rRT-PCR）之间的一致性。
重复性和实验室内精密度为1.6%-2.3%。C~C区间与C的偏差为-5.1%-4.6%。在国家参考品组上的平均（标准差）检测限为325（±141）U/mL，在活性病毒培养物上为0.07（±0.04）TCID/mL，在重组核衣壳蛋白上为0.27（±0.09）pg/mL，在灭活病毒悬液上为1.07（±1.01）TCID/mL。与对比快速检测相比，LiCA检测到的病毒抗原水平中位数低374倍（四分位距137-643）。以rRT-PCR方法为参考，总体灵敏度和特异性分别确定为97.5%（91.4%-99.7%）和99.9%（99.2%-100%）。两种方法的总一致性为99.6%（98.7%-99.9%），科恩kappa系数为0.98（0.96-1）。当Ct≤37.8时，阳性检测率为100%（95.4%-100%）。
LiCA系统为检测鼻拭子中的SARS-CoV-2抗原提供了一个具有极高灵敏度的全自动平台。作为rRT-PCR检测的替代方法，该检测方法在大规模人群新冠病毒筛查和监测中可能具有很高的应用潜力。
