Objective To determine clinical and ethnodemographic correlates of serological responses against the SARS-CoV-2 spike glycoprotein following mild-to-moderate COVID-19. Design A retrospective cohort study of healthcare workers who had self-isolated due to COVID-19. Setting University Hospitals Birmingham NHS Foundation Trust, UK (UHBFT). Participants 956 health care workers were recruited by open invitation via UHBFT trust email and social media. Intervention Participants volunteered a venous blood sample that was tested for the presence of anti-SARS-CoV-2 spike glycoprotein antibodies. Results were interpreted in the context of the symptoms of their original illness and ethnodemographic variables. Results Using an assay that simultaneously measures the combined IgG, IgA and IgM response against the spike glycoprotein (IgGAM), the overall seroprevalence within this cohort was 46.2% (n=442/956). The seroprevalence of immunoglobulin isotypes was 36.3%, 18.7% and 8.1% for IgG, IgA and IgM respectively. IgGAM identified serological responses in 40.6% (n=52/128) of symptomatic individuals who reported a negative SARS-CoV-2 PCR test. Increasing age, non-white ethnicity and obesity were independently associated with greater IgG antibody response against the spike glycoprotein. Self-reported fever and fatigue were associated with greater IgG and IgA responses against the spike glycoprotein. The combination of fever and/or cough and/or anosmia had a positive predictive value of 92.3% for seropositivity. Conclusions and relevance Assays employing combined antibody detection demonstrate enhanced seroepidemiological sensitivity and can detect prior viral exposure even when PCR swabs have been negative. We demonstrate an association between known ethnodemographic risk factors associated with mortality from COVID-19 and the magnitude of serological responses in mild-to-moderate disease. The combination of cough, and/or fever and/or anosmia identifies the majority of individuals who should self-isolate for COVID-19.

中文翻译：

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非住院感染后对 SARS-CoV-2 的血清学反应：与抗体反应幅度相关的临床和民族学特征

目的 确定轻度至中度 COVID-19 后针对 SARS-CoV-2 刺突糖蛋白的血清学反应的临床和民族学相关性。设计 对因 COVID-19 而自我隔离的医护人员进行的一项回顾性队列研究。设置英国伯明翰 NHS 基金会信托大学医院 (UHBFT)。参与者通过 UHBFT 信任电子邮件和社交媒体公开邀请招募了 956 名医护人员。干预参与者自愿提供静脉血样本，测试该样本是否存在抗 SARS-CoV-2 刺突糖蛋白抗体。结果在其原始疾病的症状和民族统计学变量的背景下进行解释。结果 使用同时测量 IgG、IgA 和 IgM 对刺突糖蛋白 (IgGAM) 的组合反应的测定，该队列的总体血清阳性率为 46.2% (n=442/956)。IgG、IgA 和 IgM 的免疫球蛋白同种型的血清阳性率分别为 36.3%、18.7% 和 8.1%。IgGAM 在 40.6% (n=52/128) 报告 SARS-CoV-2 PCR 检测呈阴性的有症状个体中发现了血清学反应。年龄增长、非白人种族和肥胖与针对刺突糖蛋白的更大 IgG 抗体反应独立相关。自我报告的发烧和疲劳与对尖峰糖蛋白的更大 IgG 和 IgA 反应有关。发烧和/或咳嗽和/或嗅觉丧失的组合对血清阳性的阳性预测值为 92.3%。结论和相关性 采用联合抗体检测的检测表明血清流行病学敏感性提高，即使 PCR 拭子呈阴性也可以检测到先前的病毒暴露。我们证明了与 COVID-19 死亡率相关的已知人种学风险因素与轻度至中度疾病的血清学反应程度之间的关联。咳嗽和/或发烧和/或嗅觉丧失共同确定了大多数应该为 COVID-19 自我隔离的人。