Damhorst Gregory L, Schoof Nils, Nguyen Phuong-Vi, Verkerke Hans, Wilber Eli, McLendon Kaleb, O'Sick William, Baugh Tyler, Cheedarla Suneethamma, Cheedarla Narayanaiah, Stittleburg Victoria, Fitts Eric C, Neja Margaret A, Babiker Ahmed, Piantadosi Anne, Roback John D, Waggoner Jesse J, Mavigner Maud, Lam Wilbur A
Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, USA.
The Atlanta Center for Microsystems-Engineered Point-of-Care Technologies, Atlanta, Georgia, USA.
Open Forum Infect Dis. 2023 May 2;10(5):ofad226. doi: 10.1093/ofid/ofad226. eCollection 2023 May.
Nasopharyngeal qualitative reverse-transcription polymerase chain reaction (RT-PCR) is the gold standard for diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but it is not practical or sufficient in every clinical scenario due to its inability to distinguish active from resolved infection. Alternative or adjunct testing may be needed to guide isolation precautions and treatment in patients admitted to the hospital.
We performed a single-center, retrospective analysis of residual clinical specimens and medical record data to examine blood plasma nucleocapsid antigen as a candidate biomarker of active SARS-CoV-2. Adult patients admitted to the hospital or presenting to the emergency department with SARS-CoV-2 ribonucleic acid (RNA) detected by RT-PCR from a nasopharyngeal swab specimen were included. Both nasopharyngeal swab and a paired whole blood sample were required to be available for analysis.
Fifty-four patients were included. Eight patients had positive nasopharyngeal swab virus cultures, 7 of whom (87.5%) had concurrent antigenemia. Nineteen (79.2%) of 24 patients with detectable subgenomic RNA and 20 (80.0%) of 25 patients with N2 RT-PCR cycle threshold ≤ 33 had antigenemia.
Most individuals with active SARS-CoV-2 infection are likely to have concurrent antigenemia, but there may be some individuals with active infection in whom antigenemia is not detectable. The potential for high sensitivity and convenience of a blood test prompts interest in further investigation as a screening tool to reduce reliance on nasopharyngeal swab sampling and as an adjunct diagnostic test to aid in clinical decision making during the period after acute coronavirus disease 2019.
鼻咽定性逆转录聚合酶链反应（RT-PCR）是诊断严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染的金标准，但由于其无法区分现症感染与既往感染，在所有临床场景中并不实用或充分。可能需要采用替代检测或辅助检测来指导住院患者的隔离防护措施及治疗。
我们对剩余临床标本和病历数据进行了单中心回顾性分析，以检验血浆核衣壳抗原作为现症SARS-CoV-2候选生物标志物的情况。纳入了通过鼻咽拭子标本的RT-PCR检测出SARS-CoV-2核糖核酸（RNA）的住院成年患者或前往急诊科就诊的成年患者。需要同时具备鼻咽拭子和配对的全血样本用于分析。
共纳入54例患者。8例患者鼻咽拭子病毒培养呈阳性，其中7例（87.5%）同时存在抗原血症。24例可检测到亚基因组RNA的患者中有19例（79.2%）以及25例N2 RT-PCR循环阈值≤33的患者中有20例（80.0%）存在抗原血症。
大多数现症SARS-CoV-2感染个体可能同时存在抗原血症，但可能有一些现症感染个体无法检测到抗原血症。血液检测具有高灵敏度和便利性的潜力，这促使人们有兴趣进一步研究将其作为一种筛查工具，以减少对鼻咽拭子采样的依赖，并作为一种辅助诊断检测手段，在2019冠状病毒病急性期后的阶段辅助临床决策。
