Department of Transfusion Medicine, University Hospital of Salzburg (SALK), Paracelsus Medical University (PMU) Salzburg, Müllner-Hauptstraße 48, Salzburg, 5020, Austria.
Team Biostatistics and Big Medical Data, IDA Lab Salzburg, PMU Salzburg, Strubergasse 16, Salzburg, 5020, Austria.
BMC Infect Dis. 2023 Nov 15;23(1):800. doi: 10.1186/s12879-023-08820-w.
Post-COVID-19-Syndrome (PCS) frequently occurs after an infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, the understanding of causative mechanisms is still limited. Aim of this study was to determine the PCS rate among SARS-CoV-2 seropositive blood donors as representatives of supposedly healthy adults, who had experienced an asymptomatic or mild COVID-19 disease course, and to examine whether Epstein-Barr virus (EBV) is reactivated in individuals reporting PCS.
The PCS rate was determined using questionnaires that included questions about infection and persistent symptoms. Pre-pandemic blood samples and samples collected at regular, pre-defined times after a SARS-CoV-2 infection were analysed for neopterin, a marker for antiviral immune responses, by an enzyme-linked immunosorbent assay (ELISA). Additionally, we determined the rate of SARS-CoV-2 anti-N total antibodies using an electrochemiluminescence immunoassay (ECLIA). Furthermore, quantitative real-time polymerase chain reaction (qPCR) to detect EBV DNA and ECLIA screening for EBV viral capsid-antigen (VCA) IgM, IgG and EBV nuclear antigen 1 (EBNA) IgG were performed.
Our data reveal that 18% of all infections result in PCS, with symptoms lasting for up to one year. In individuals reporting PCS, no elevated levels of neopterin were detected, indicating no persisting pro-inflammatory, antiviral immune response. SARS-CoV-2 antibody levels were declining in all participants in comparable manner over time, pointing to a successful virus clearance. In individuals with PCS, no EBV DNA could be detected. Furthermore, no differences in EBV specific antibody levels could be shown in PCS groups compared to non-PCS groups.
Our data suggest that PCS in per se healthy, immunocompetent adults cannot be ascribed to a reactivation of EBV.
新冠病毒（SARS-CoV-2）感染后常发生新冠后综合征（PCS）。然而，其发病机制仍不清楚。本研究旨在确定 SARS-CoV-2 血清阳性献血者作为假定健康成年人的 PCS 发生率，这些献血者曾经历过无症状或轻症 COVID-19 病程，并检查报告 PCS 的个体中是否存在 EBV 再激活。
使用包括感染和持续症状问题的问卷来确定 PCS 发生率。通过酶联免疫吸附试验（ELISA）分析了大流行前的血液样本和 SARS-CoV-2 感染后定期、预先定义的时间采集的样本中的新蝶呤，新蝶呤是抗病毒免疫反应的标志物。此外，我们使用电化学发光免疫分析法（ECLIA）测定了 SARS-CoV-2 抗 N 总抗体的发生率。此外，进行了定量实时聚合酶链反应（qPCR）以检测 EBV DNA，以及 ECLIA 筛查 EBV 衣壳抗原（VCA）IgM、IgG 和 EBV 核抗原 1（EBNA）IgG。
我们的数据显示，所有感染中有 18%导致 PCS，症状持续长达一年。在报告 PCS 的个体中，未检测到新蝶呤水平升高，表明不存在持续的促炎、抗病毒免疫反应。随着时间的推移，所有参与者的 SARS-CoV-2 抗体水平均以相似的方式下降，表明病毒清除成功。在 PCS 个体中，未检测到 EBV DNA。此外，与非 PCS 组相比，在 PCS 组中，EBV 特异性抗体水平没有差异。
我们的数据表明，在本身健康、免疫功能正常的成年人中，PCS 不能归因于 EBV 的再激活。
