Division of Immunology, Transplantation and Infectious Disease, IRCCS Ospedale San Raffaele, Milano, Italy.
CUSSB-University Center for Statistics in the Biomedical Sciences, Vita-Salute San Raffaele Universitygrid.15496.3f, Milano, Italy.
Microbiol Spectr. 2021 Oct 31;9(2):e0025021. doi: 10.1128/Spectrum.00250-21. Epub 2021 Sep 22.
During the last year, mass screening campaigns have been carried out to identify immunological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and establish a possible seroprevalence. The obtained results gained new importance with the beginning of the SARS-CoV-2 vaccination campaign, as the lack of doses has persuaded several countries to introduce different policies for individuals who had a history of COVID-19. Lateral flow assays (LFAs) may represent an affordable tool to support population screening in low-middle-income countries, where diagnostic tests are lacking and epidemiology is still widely unknown. However, LFAs have demonstrated a wide range of performance, and the question of which one could be more valuable in these settings still remains. We evaluated the performance of 11 LFAs in detecting SARS-CoV-2 infection, analyzing samples collected from 350 subjects. In addition, samples from 57 health care workers collected at 21 to 24 days after the first dose of the Pfizer-BioNTech vaccine were also evaluated. LFAs demonstrated a wide range of specificity (92.31% to 100%) and sensitivity (50% to 100%). The analysis of postvaccination samples was used to describe the most suitable tests to detect IgG response against S protein receptor binding domain (RBD). Tuberculosis (TB) therapy was identified as a potential factor affecting the specificity of LFAs. This analysis identified which LFAs represent a valuable tool not only for the detection of prior SARS-CoV-2 infection but also for the detection of IgG elicited in response to vaccination. These results demonstrated that different LFAs may have different applications and the possible risks of their use in high-TB-burden settings. Our study provides a fresh perspective on the possible employment of SARS-CoV-2 LFA antibody tests. We developed an in-depth, large-scale analysis comparing LFA performance to enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence immunoassay (ECLIA) and evaluating their sensitivity and specificity in identifying COVID-19 patients at different time points from symptom onset. Moreover, for the first time, we analyzed samples of patients undergoing treatment for endemic poverty-related diseases, especially tuberculosis, and we evaluated the impact of this therapy on test specificity in order to assess possible performance in TB high-burden countries.
在过去的一年中，已经开展了大规模的筛查活动，以确定对严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 的免疫反应，并确定可能的血清流行率。随着 SARS-CoV-2 疫苗接种活动的开始，这些结果获得了新的重要性，因为剂量的缺乏促使几个国家对有 COVID-19 病史的人引入了不同的政策。侧向流动分析 (LFA) 可能代表一种经济实惠的工具，可以支持中低收入国家的人群筛查，在这些国家缺乏诊断测试，且流行病学知识仍然知之甚少。然而，LFA 已经证明了其性能的广泛范围，因此，在这些环境中，哪种 LFA 更有价值的问题仍然存在。我们评估了 11 种 LFA 在检测 SARS-CoV-2 感染方面的性能，分析了从 350 名受试者收集的样本。此外，还评估了从 57 名医护人员收集的样本，这些样本是在接种辉瑞-生物技术公司疫苗第一剂后 21 至 24 天采集的。LFA 表现出广泛的特异性 (92.31% 至 100%) 和敏感性 (50% 至 100%)。对疫苗接种后样本的分析用于描述最适合检测针对 S 蛋白受体结合域 (RBD) 的 IgG 反应的测试。结核病 (TB) 治疗被确定为影响 LFA 特异性的一个潜在因素。这项分析确定了哪些 LFA 不仅是检测先前 SARS-CoV-2 感染的有价值的工具，也是检测针对疫苗接种产生的 IgG 的有价值的工具。这些结果表明，不同的 LFA 可能有不同的应用，以及在高结核病负担环境中使用它们的可能风险。我们的研究提供了一个关于 SARS-CoV-2 LFA 抗体测试可能应用的新视角。我们进行了一项深入的、大规模的分析，比较了 LFA 的性能与酶联免疫吸附试验 (ELISA) 和电化学发光免疫分析 (ECLIA)，并评估了它们在不同时间点从症状出现开始识别 COVID-19 患者的敏感性和特异性。此外，这是我们首次分析了正在接受治疗的与贫困相关的地方性疾病，特别是结核病的患者样本，并评估了这种治疗对测试特异性的影响，以评估其在结核病高负担国家的可能性能。
