Dr. Alexandra Domnica Hoeggerl (Salzburg/ AT), Dr. Verena Nunhofer (Salzburg/ AT), Wanda Lauth (Salzburg/ AT), Natalie Badstuber (Salzburg/ AT), Nina Held (Salzburg/ AT), Dr. Georg Zimmermann (Salzburg/ AT), PD Dr. Christoph Grabmer (Salzburg/ AT), Dr. Lisa Weidner (Wien/ AT), Dr. Christof Jungbauer (Wien/ AT), Dr. Nadja Lindlbauer (Salzburg/ AT), Dr. Heidrun Neureiter (Salzburg/ AT), Prof. Dr. Tuulia Ortner (Salzburg/ AT), Prof. Dr. Maria Flamm (Salzburg/ AT), Prof. Dr. Jürgen Osterbrink (Salzburg/ AT), Univ.-Prof. Dr. Eva Rohde (Salzburg/ AT), PD Dr. Sandra Laner-Plamberger (Salzburg/ AT)
Background
Post-COVID-19-Syndrome (PCS) frequently occurs after an infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and is a long-lasting health impairment with a broad range of symptoms. Currently the causative mechanisms remain elusive. Aim of this study was to investigate the PCS rate of SARS-CoV-2 seropositive blood donors as representatives of supposedly healthy adults (n = 400) and to examine whether Epstein-Barr-Virus (EBV) is reactivated in individuals reporting PCS.
Methods
To ensure that a SARS-CoV-2 infection was experienced, SARS-CoV-2 anti-N total antibodies, which are produced after an infection only, were monitored by an electrochemiluminescence immunoassay (ECLIA). Participants had to fill in questionnaires regarding the time and course of the infection and persisting symptoms, allowing the determination of the PCS rate. Applying ECLIA, the levels of EBV viral capsid-antigen (VCA) IgM, IgG and EBV nuclear antigen 1 (EBNA) IgG were determined. In addition, we performed qRT-PCR to detect EBV DNA. Furthermore, we examined the amount of neopterin, a prognostic marker for a pro-inflammatory immune status, by an enzyme-linked immunosorbent assay (ELISA) and compared it to pre-pandemic values.
Results
Our data reveal that 18% of SARS-CoV-2 infections result in PCS, with symptoms lasting for up to one year. Quantity and functionality of specific SARS-CoV-2 antibodies were declining in individuals with and without PCS over time, excluding unrecognized reinfections with SARS-CoV-2. All individuals reporting PCS were screened negative for EBV DNA. Furthermore, antibody profiles of VCA IgM, IgG and EBNA IgG revealed past EBV infections in all individuals screened but did not indicate an acute phase of EBV infection after a SARS-CoV-2 infection. Additionally, no elevated levels of neopterin could be found, indicating no pro-inflammatory immune status or enhanced macrophage-related antiviral immune response compared to individuals without PCS.
Conclusion
Our data did not reveal detectable levels of EBV DNA, a specific antibody response, pro-inflammatory immune status or macrophage-related immune response in healthy adults reporting PCS. Therefore, our study indicates that PCS in immunocompetent adults may not be explained by a reactivation of EBV or by persisting inflammatory processes. Further examination is required to identify the cause of PCS.
Offenlegung Interessenkonflikt:
none.