SARS-CoV-2-IgG response is different in COVID-19 outpatients and asymptomatic contact persons
SARS-CoV-2-IgG response is different in COVID-19 outpatients and asymptomatic contact persons
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DOI：
10.1016/j.jcv.2020.104542
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发表时间：
2020-09-01
影响因子：
8.8
通讯作者：
Deininger, Susanne
中科院分区：
文献类型：
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作者：
Wellinghausen, Nele;Plonne, Dietmar;Deininger, Susanne
已经开发了商业上可获得的免疫测定法，用于灵敏和特异地检测SARS-CoV-2抗体。虽然已经报道了来自住院COVID-19患者的样本的快速和可靠的IgG反应，但对门诊患者的了解较少。我们通过抗SARS-CoV-2-ELISA IgG（Euroimmun）在一个确定的SARS-CoV-2-PCR确认的门诊患者和无症状接触者队列中评估了SARS-CoV-2-IgG应答，其中包括来自PCR确认的门诊患者（n = 111）和无症状但PCR阳性的接触者（n = 26）的137份血清样本，这些样本被送到我们的实验室作为测定SARS-CoV-2-IgG的常规诊断的一部分。SARS-CoV-2-IgG的总体阳性率在门诊患者中为81.1%（无论在症状发作后第21天之前或之后采样），但在无症状接触者中显著较低（15.4%，p < 0.0001）。在无症状的接触者中，PCR检测的ct值显著高于门诊患者（5-7个阈值循环），ct值与SARS-CoV-2-IgG比率显著负相关，表明较低的病毒载量可能是血清阳性率较低的解释。总之，我们的研究表明，包括无症状患者在内的门诊患者对SARS-CoV-2的血清学反应不如住院患者明显。迫切需要进行进一步的对照研究，以确定门诊病人和无症状者的血清学反应，因为这是血清流行病学调查的主要目标人群。
Commercially available immunoassays have been developed for sensitive and specific detection of antibodies against SARS-CoV-2. While a fast and reliable IgG response has been reported for samples from hospitalized COVID-19 patients, less is known about ambulatory patients. We evaluated the SARS-CoV-2-IgG response by the Anti-SARS-CoV-2-ELISA IgG (Euroimmun) in a defined cohort of SARS-CoV-2-PCR-confirmed outpatients and asymptomatic contact persons including 137 serum samples from PCR-confirmed outpatients (n = 111) and asymptomatic but PCR-positive contact persons (n = 26) sent to our laboratory as part of routine diagnostics for determination of SARS-CoV-2-IgG. Overall positivity rate for SARS-CoV-2-IgG was 81.1 % in outpatients (irrespective of sampling before or after day 21 after onset of symptoms) but significantly lower in asymptomatic contact persons (15.4 %, p < 0.0001). In contact persons without symptoms the ct values of the PCR assays were significantly higher (5-7 threshold cycles) than in outpatients, and ct values were significantly negative correlated to the SARS-CoV-2-IgG ratio, suggesting a lower viral load as a possible explanation for lower rate of seropositivity. In summary, our study shows that serological response to SARS-CoV-2 in outpatients including asymptomatic persons is less pronounced than in hospitalized patients. Further controlled studies are urgently needed to determine serological response in outpatients and asymptomatic persons since this is the main target population for seroepidemiological investigations.