Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, Rome, Italy.
Dipartimento di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.
Clin Chem Lab Med. 2021 Apr 7;59(8):1468-1476. doi: 10.1515/cclm-2021-0182. Print 2021 Jul 27.
Compared to RT-PCR, lower performance of antigen detection assays, including the Lumipulse G SARS-CoV-2 Ag assay, may depend on specific testing scenarios.
We tested 594 nasopharyngeal swab samples from individuals with COVID-19 (RT-PCR cycle threshold [Ct] values ≤ 40) or non-COVID-19 (Ct values >40) diagnoses. RT-PCR positive samples were assigned to diagnostic, screening, or monitoring groups of testing.
With a limit of detection of 1.2 × 10 SARS-CoV-2 RNA copies/mL, Lumipulse showed positive percent agreement (PPA) of 79.9% (155/194) and negative percent agreement of 99.3% (397/400), whereas PPAs were 100% for samples with Ct values of <18 or 18-<25 and 92.5% for samples with Ct values of 25-<30. By three groups, Lumipulse showed PPA of 87.0% (60/69), 81.1% (43/53), or 72.2% (52/72), respectively, whereas PPA was 100% for samples with Ct values of <18 or 18-<25, and was 94.4, 80.0, or 100% for samples with Ct values of 25-<30, respectively. Additional testing of RT-PCR positive samples for SARS-CoV-2 subgenomic RNA showed that, by three groups, PPA was 63.8% (44/69), 62.3% (33/53), or 33.3% (24/72), respectively. PPAs dropped to 55.6, 20.0, or 41.7% for samples with Ct values of 25-<30, respectively. All 101 samples with a subgenomic RNA positive result had a Lumipulse assay's antigen positive result, whereas only 54 (58.1%) of remaining 93 samples had a Lumipulse assay's antigen positive result.
Lumipulse assay was highly sensitive in samples with low RT-PCR Ct values, implying repeated testing to reduce consequences of false-negative results.
与 RT-PCR 相比，抗原检测试剂盒（包括 Lumipulse G SARS-CoV-2 Ag 检测试剂盒）的性能较低，这可能取决于特定的检测情况。
我们测试了 594 份来自 COVID-19 个体（RT-PCR 循环阈值 [Ct] 值≤40）或非 COVID-19 个体（Ct 值>40）的鼻咽拭子样本。将 RT-PCR 阳性样本分配到诊断、筛查或监测检测组。
在检测限为 1.2×10 SARS-CoV-2 RNA 拷贝/mL 的情况下，Lumipulse 显示出 79.9%（155/194）的阳性百分一致率（PPA）和 99.3%（397/400）的阴性百分一致率，而对于 Ct 值<18 或 18-<25 的样本，PPA 为 100%，对于 Ct 值为 25-<30 的样本，PPA 为 92.5%。按三组计算，Lumipulse 的 PPA 分别为 87.0%（60/69）、81.1%（43/53）或 72.2%（52/72），而对于 Ct 值<18 或 18-<25 的样本，PPA 为 100%，对于 Ct 值为 25-<30 的样本，PPA 分别为 94.4%、80.0%或 100%。对 RT-PCR 阳性样本进行 SARS-CoV-2 亚基因组 RNA 的进一步检测显示，按三组计算，PPA 分别为 63.8%（44/69）、62.3%（33/53）或 33.3%（24/72），对于 Ct 值为 25-<30 的样本，PPA 分别降至 55.6%、20.0%或 41.7%。所有 101 份亚基因组 RNA 阳性结果的样本均有 Lumipulse 检测的抗原阳性结果，而在其余 93 份样本中，仅有 54 份（58.1%）有 Lumipulse 检测的抗原阳性结果。
Lumipulse 检测在 RT-PCR Ct 值较低的样本中具有高度敏感性，提示重复检测以减少假阴性结果的后果。
