Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA.
Department of Pathology, University of California, San Francisco, San Francisco, CA, USA.
Nat Commun. 2020 Sep 17;11(1):4698. doi: 10.1038/s41467-020-18468-8.
Given the limited availability of serological testing to date, the seroprevalence of SARS-CoV-2-specific antibodies in different populations has remained unclear. Here, we report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seroreactivity was 0.26% in 387 hospitalized patients admitted for non-respiratory indications and 0.1% in 1,000 blood donors in early April 2020. We additionally describe the longitudinal dynamics of immunoglobulin-G (IgG), immunoglobulin-M (IgM), and in vitro neutralizing antibody titers in COVID-19 patients. The median time to seroconversion ranged from 10.3-11.0 days for these 3 assays. Neutralizing antibodies rose in tandem with immunoglobulin titers following symptom onset, and positive percent agreement between detection of IgG and neutralizing titers was >93%. These findings emphasize the importance of using highly accurate tests for surveillance studies in low-prevalence populations, and provide evidence that seroreactivity using SARS-CoV-2 anti-nucleocapsid protein IgG and anti-spike IgM assays are generally predictive of in vitro neutralizing capacity.
鉴于迄今为止血清学检测的可用性有限，不同人群中 SARS-CoV-2 特异性抗体的血清流行率仍不清楚。在这里，我们报告了两个旧金山湾区人群中 SARS-CoV-2 的血清流行率非常低。2020 年 4 月初，387 名因非呼吸道疾病住院的患者中，有 0.26%的患者出现血清反应性，1000 名献血者中有 0.1%的患者出现血清反应性。我们还描述了 COVID-19 患者中免疫球蛋白 G（IgG）、免疫球蛋白 M（IgM）和体外中和抗体滴度的纵向动态。对于这 3 种检测方法，血清转化的中位数时间范围为 10.3-11.0 天。中和抗体在症状出现后与免疫球蛋白滴度同时升高，IgG 和中和滴度检测的阳性符合率>93%。这些发现强调了在低流行人群中使用高度准确的检测方法进行监测研究的重要性，并提供了证据表明使用 SARS-CoV-2 抗核衣壳蛋白 IgG 和抗刺突 IgM 检测的血清反应性通常可预测体外中和能力。
