Background: Microarray technology may offer a new opportunity to gain insight into disease-specific global protein expression profiles. The present study was performed to apply a serum antibody microarray to screen for differentially regulated cytokines in Parkinson's disease (PD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). Results: Serum samples were obtained from patients with clinical diagnoses of PD (n = 117), MSA (n = 31) and PSP/CBS (n = 38) and 99 controls. Cytokine profiles of sera from patients and controls were analyzed with a semiquantitative human antibody array for 174 cytokines and the expression of 12 cytokines was found to be significantly altered. In a next step, results from the microarray experiment were individually validated by different immunoassays. Immunoassay validation confirmed a significant increase of median PDGF-BB levels in patients with PSP/CBS, MSA and PD and a decrease of median prolactin levels in PD. However, neither PDGF-BB nor prolactin were specific biomarkers to discriminate PSP/CBS, MSA, PD and controls. Conclusions: In our unbiased cytokine array based screening approach and validation by a different immunoassay only two of 174 cytokines were significantly altered between patients and controls.

The developmental course of antibodies produced after a SARS-CoV-2 infection has been insufficiently investigated so far. Therefore, the aim of this study was to investigate the dynamics of SARS-CoV-2 antibody levels against the viral nucleocapsid- and spike-protein among Austrian blood donors as a representative group of a supposedly healthy population within the first year after a SARS-CoV-2 infection. The impact of age, sex, vaccination status, AB0-blood group and awareness about the infection was evaluated. Our study shows that the level of anti-N antibodies is declining, while anti-S antibody levels remain stable. Antibodies detected were functional in vitro. Age, sex and blood group do not influence antibody dynamics. However, blood group AB shows significantly lower antibody levels and in vitro functionality compared to other blood groups. Our data reveal that one out of five individuals was not aware of a previous SARS-CoV-2 infection and that the disease course neither affects the level of antibody production nor the in vitro functionality. We also found that 14% of participants show persisting COVID-19-related symptoms for up to nine months. Our results provide valuable insights into the dynamics of the immune response after a SARS-CoV-2 infection in a representative cohort of adult blood donors in Central Europe.

Background and Objectives: The coronavirus disease 2019 (COVID‐19) pandemic necessitated various therapeutic approaches, including convalescent plasma (CP) administration. The administration timing of COVID‐19 CP (CCP), antibody specificity and quantity were identified as crucial factors for therapeutic success. Currently, antibody durability and storage time are still under debate. The aim of this study was to evaluate the stability and in vitro functionality of severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2) antibodies in human plasma and serum after long‐term storage, to provide a framework for generally applicable rules regarding the long‐term storage of CCP.Materials and Methods: Serum and plasma samples of CCP donations were investigated at the time of donation and after 2 and 3 years' storage at less than −30°C using (electro)chemiluminescence immunoassays and enzyme‐linked immunosorbent assays, with the plasma undergoing multiple freezing and thawing.Results: Our data reveal robust levels of SARS‐CoV‐2 antibodies after long‐term storage. Furthermore, our findings also indicate that multiple freezing and thawing cycles do not affect the antibody levels or their neutralizing capability.Conclusion: As antibody stability and in vitro functionality are maintained over extended periods, even after repeated freezing and thawing, our findings support long‐term storage of CCP, particularly benefiting vulnerable populations such as immunocompromised individuals. By now, donors have likely encountered various SARS‐CoV‐2 variants and vaccine‐acquired antibodies. This antibody mix present in CCP is suggested to protect even against new variants. Our data indicate that current regulations for the storage of CCP can be extended and that CCPs could be used for therapeutic purposes after long‐term storage without significant loss of antibody quantity.