Departamento De Microbiología Clínica, Hospital Universitario Príncipe De Asturias, Madrid, Spain.
Departamento De Microbiología Clínica, Hospital Universitario Príncipe De Asturias, Madrid, Spain; Departamento De Biomedicina y Biotecnología, Facultad De Medicina, Universidad De Alcalá De Henares, Spain.
J Clin Virol. 2020 Aug;129:104473. doi: 10.1016/j.jcv.2020.104473. Epub 2020 May 27.
SARS-CoV-2 infection diagnosis is challenging in patients from 2 to 3 weeks after the onset of symptoms, due to the low positivity rate of the PCR. Serologic tests could be complementary to PCR in these situations. The aim of our study was to analyze the diagnostic performance of one serologic rapid test in COVID-19 patients.
We evaluated a lateral flow immunoassay (AllTest COVID-19 IgG/IgM) which detects IgG and IgM antibodies. We validated the serologic test using serum samples from 100 negative patients (group 1) and 90 patients with COVID-19 confirmed by PCR (group 2). Then, we prospectively evaluated the test in 61 patients with clinical diagnosis of pneumonia of unknown etiology that were negative for SARS-CoV-2 by PCR (group 3).
All 100 patients from group 1 were negative for the serologic test (specificity = 100 %). Regarding group 2 (PCR-positive), the median time from their symptom onset until testing was 17 days. For these 90 group-2 patients, the test was positive for either IgM or IgG in 58 (overall sensitivity = 64.4 %), and in patients tested 14 days or more after the onset of symptoms, the sensitivity was 88.0 %. Regarding the 61 group-3 patients, median time after symptom onset was also 17 days, and the test was positive in 54 (88.5 % positivity).
Our study shows that Alltest lateral flow immunoassay is reliable as a complement of PCR to diagnose SARS-CoV-2 infection after 14 days from the onset of symptoms and in patients with pneumonia and negative PCR for SARS-CoV-2.
由于 PCR 的阳性率较低，在症状出现后 2 至 3 周的患者中，SARS-CoV-2 感染的诊断具有挑战性。在这些情况下，血清学检测可能是 PCR 的补充。本研究的目的是分析一种血清学快速检测在 COVID-19 患者中的诊断性能。
我们评估了一种侧向流动免疫测定法（AllTest COVID-19 IgG/IgM），该法可检测 IgG 和 IgM 抗体。我们使用来自 100 例阴性患者（第 1 组）和 90 例经 PCR 证实的 COVID-19 患者（第 2 组）的血清样本验证了血清学检测。然后，我们前瞻性评估了 61 例临床诊断为肺炎且 PCR 检测为 SARS-CoV-2 阴性的患者（第 3 组）。
第 1 组的 100 例患者的血清学检测均为阴性（特异性=100%）。第 2 组（PCR 阳性）的中位发病至检测时间为 17 天。对于这 90 例第 2 组患者，58 例患者的 IgM 或 IgG 检测为阳性（总敏感性=64.4%），并且在症状出现后 14 天或更长时间检测时，敏感性为 88.0%。对于第 3 组的 61 例患者，症状出现后的中位时间也是 17 天，54 例患者的检测结果为阳性（88.5%阳性率）。
本研究表明，Alltest 侧向流动免疫测定法是可靠的，可以作为 PCR 的补充，用于在症状出现后 14 天以及患有肺炎且 PCR 检测为 SARS-CoV-2 阴性的患者中诊断 SARS-CoV-2 感染。
