Tedim Ana P, Almansa Raquel, Domínguez-Gil Marta, González-Rivera Milagros, Micheloud Dariela, Ryan Pablo, Méndez Raúl, Blanca-López Natalia, Pérez-García Felipe, Bustamante Elena, Gómez José Manuel, Doncel Cristina, Trapiello Wysali, Kelvin Alyson A, Booth Ryan, Ostadgavahi Ali Toloue, Oneizat Ruth, Puertas Carolina, Barbé Ferrán, Ferrer Ricard, Menéndez Rosario, Bermejo-Martin Jesús F, Eiros José María, Kelvin David J, Torres Antoni
Group for Biomedical Research in Sepsis (BioSepsis), Instituto de Investigación Biomédica de Salamanca, Salamanca, Spain.
Hospital Universitario Río Hortega, Valladolid, Spain.
Eur J Clin Invest. 2021 Jun;51(6):e13501. doi: 10.1111/eci.13501. Epub 2021 Feb 8.
The presence of SARS-CoV-2 RNA in plasma has been linked to disease severity and mortality. We compared RT-qPCR to droplet digital PCR (ddPCR) to detect SARS-CoV-2 RNA in plasma from COVID-19 patients (mild, moderate, and critical disease).
The presence/concentration of SARS-CoV-2 RNA in plasma was compared in three groups of COVID-19 patients (30 outpatients, 30 ward patients and 30 ICU patients) using both RT-qPCR and ddPCR. Plasma was obtained in the first 24h following admission, and RNA was extracted using eMAG. ddPCR was performed using Bio-Rad SARS-CoV-2 detection kit, and RT-qPCR was performed using GeneFinder™ COVID-19 Plus RealAmp Kit. Statistical analysis was performed using Statistical Package for the Social Science.
SARS-CoV-2 RNA was detected, using ddPCR and RT-qPCR, in 91% and 87% of ICU patients, 27% and 23% of ward patients and 3% and 3% of outpatients. The concordance of the results obtained by both methods was excellent (Cohen's kappa index = 0.953). RT-qPCR was able to detect 34/36 (94.4%) patients positive for viral RNA in plasma by ddPCR. Viral RNA load was higher in ICU patients compared with the other groups (P < .001), by both ddPCR and RT-qPCR. AUC analysis revealed Ct values (RT-qPCR) and viral RNA load values (ddPCR) can similarly differentiate between patients admitted to wards and to the ICU (AUC of 0.90 and 0.89, respectively).
Both methods yielded similar prevalence of RNAemia between groups, with ICU patients showing the highest (>85%). RT-qPCR was as useful as ddPCR to detect and quantify SARS-CoV-2 RNAemia in plasma.
血浆中严重急性呼吸综合征冠状病毒2（SARS-CoV-2）RNA的存在与疾病严重程度和死亡率相关。我们比较了逆转录定量聚合酶链反应（RT-qPCR）和液滴数字聚合酶链反应（ddPCR）检测新型冠状病毒肺炎（COVID-19）患者（轻症、中症和重症）血浆中SARS-CoV-2 RNA的情况。
使用RT-qPCR和ddPCR对三组COVID-19患者（30名门诊患者、30名病房患者和30名重症监护病房患者）血浆中SARS-CoV-2 RNA的存在/浓度进行比较。在入院后的头24小时内采集血浆，并使用eMAG提取RNA。使用伯乐SARS-CoV-2检测试剂盒进行ddPCR，使用GeneFinder™ COVID-19 Plus RealAmp试剂盒进行RT-qPCR。使用社会科学统计软件包进行统计分析。
使用ddPCR和RT-qPCR分别在91%和87%的重症监护病房患者、27%和23%的病房患者以及3%和3%的门诊患者中检测到SARS-CoV-2 RNA。两种方法所得结果的一致性非常好（科恩kappa指数=0.953）。RT-qPCR能够检测出ddPCR显示血浆中病毒RNA呈阳性的34/36（94.4%）患者。通过ddPCR和RT-qPCR检测，重症监护病房患者的病毒RNA载量均高于其他组（P<0.001）。曲线下面积分析显示，Ct值（RT-qPCR）和病毒RNA载量值（ddPCR）同样能够区分病房患者和重症监护病房患者（曲线下面积分别为0.90和0.89）。
两种方法在各组中检测到的病毒血症患病率相似，重症监护病房患者的患病率最高（>85%）。RT-qPCR在检测和定量血浆中SARS-CoV-2病毒血症方面与ddPCR同样有效。
