Cocchio Silvia, Nicoletti Michele, Cozzolino Claudia, Mazzitelli Maria, Bonadiman Nicola, Gardin Samuele, Sasset Lolita, Zucconi Melissa, Cattelan Anna Maria, Baldo Vincenzo
Department of Cardiac, Thoracic, Vascular Sciences, and Public Health, University of Padua, Padua, Italy.
Infectious and Tropical Diseases Unit, Padua University Hospital, Padua, Italy.
Heliyon. 2024 Jun 18;10(12):e33229. doi: 10.1016/j.heliyon.2024.e33229. eCollection 2024 Jun 30.
The introduction of rapid antigen tests revolutionized the approach to SARS-CoV-2 diagnosis, offering prompt and accurate results with high sensitivity and specificity. Although it is more cost- and time-saving than the gold standard, real-time polymerase chain reaction (RT-PCR), the efficacy in general population screening in both hospital- and community-based settings remains unknown. Moreover, rapid antigen testing is limited by qualitative results. This study aims to evaluate the diagnostic reliability of the LumiraDx™ rapid antigen test during the Omicron era and to investigate its quantitative (analogue-to-digital converter (ADC)) results in comparison with RT-PCR Ct values.
This prospective study included all adult patients with mild-to-moderate SARS-CoV-2 symptoms who were not hospitalised and did not require oxygen supplementation, consented to participate, and attended the Infectious and Tropical Diseases Unit of Padua University Hospital from July 14th, 2022 to January 3rd, 2023. The patients underwent two different tests simultaneously: a nasal LumiraDx™ swab and a real-time RT-PCR assay performed on a nasopharyngeal swab. Sampling was repeated several times for a subset of subjects.
We enrolled 266 consecutive participants and collected 601 pairs of LumiraDx™ and RT-PCR samples. The most prevalent variant was BA.4/BA.5 Omicron (60.2 %). The sensitivity and specificity of LumiraDx™ test when compared to real-time RT-PCR results as the reference standard were 93.1 % and 79.75 %, respectively. No significant differences in diagnostic reliability were found based on the available characteristics, age, sex, symptom status, or COVID-19 variant, except for the days from symptom onset. According to the multilevel logistic regression analysis, the only independent variable significantly associated with test concordance was the Ct value (adjusted odds ratio (OR) = 0.56, p < 0.001). Significant differences in quantitative ADC values were found between false negative (FN) true negative (TN), and false positive (FP) and true positive (TP) tests.
This study showed that LumiraDx™ test is reliable for SARS-CoV-2 diagnosis in patients with mild-to-moderate SARS-CoV-2 symptoms. This finding confirms the efficacy of rapid antigen tests in monitoring vulnerable individuals during the current post-vaccination era. When compared with the RT-PCR, LumiraDx™ test effectively quantitatively distinguishes between FN and TN cases, as well as FP and true TP tests, despite inaccuracies in qualitative results.
快速抗原检测的引入彻底改变了严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的诊断方法，能够以高灵敏度和特异性提供快速准确的结果。尽管它比金标准实时聚合酶链反应（RT-PCR）更节省成本和时间，但在医院和社区环境下对普通人群进行筛查的效果仍不明确。此外，快速抗原检测受限于定性结果。本研究旨在评估LumiraDx™快速抗原检测在奥密克戎时代的诊断可靠性，并将其定量（模数转换器（ADC））结果与RT-PCR的Ct值进行比较。
这项前瞻性研究纳入了所有未住院、不需要吸氧、同意参与且于2022年7月14日至2023年1月3日就诊于帕多瓦大学医院感染与热带病科的有轻至中度SARS-CoV-2症状的成年患者。患者同时接受两种不同检测：鼻腔LumiraDx™拭子检测和鼻咽拭子实时RT-PCR检测。对部分受试者重复采样数次。
我们连续纳入了266名参与者，收集了601对LumiraDx™和RT-PCR样本。最常见的变异株是奥密克戎BA.4/BA.5（60.2%）。以实时RT-PCR结果作为参考标准时，LumiraDx™检测的灵敏度和特异性分别为93.1%和79.75%。除了症状出现后的天数外，根据现有特征、年龄、性别、症状状态或COVID-19变异株，未发现诊断可靠性存在显著差异。根据多水平逻辑回归分析，与检测一致性显著相关的唯一自变量是Ct值（调整优势比（OR）=0.56，p<0.001）。在假阴性（FN）与真阴性（TN）以及假阳性（FP）与真阳性（TP）检测之间，定量ADC值存在显著差异。
本研究表明，LumiraDx™检测对于有轻至中度SARS-CoV-2症状的患者进行SARS-CoV-2诊断是可靠的。这一发现证实了快速抗原检测在当前疫苗接种后时代监测易感个体方面的有效性。与RT-PCR相比，尽管定性结果存在不准确之处，但LumiraDx™检测能有效定量区分FN和TN病例，以及FP和真TP检测。
