Donors for SARS-CoV-2 convalescent plasma for a controlled clinical trial : donor characteristics, content and time course of SARS-CoV-2 neutralizing antibodies
Creators: name: Körper, Sixten
name: Jahrsdörfer, Bernd
name: Corman, Victor M.
name: Pilch, Jan
name: Wuchter, Patrick
name: Blasczyk, Rainer
name: Müller, Rebecca
name: Tonn, Torsten
name: Bakchoul, Tamam
name: Schäfer, Richard
name: Juhl, David
name: Schwarz, Tatjana
name: Gödecke, Nina
name: Burkhardt, Thomas
name: Schmidt, Michael
name: Appl, Thomas
name: Eichler, Hermann
name: Klüter, Harald
name: Drosten, Christian
name: Seifried, Erhard
name: Schrezenmeier, Hubert
Publisher: name: Universität Ulm
Year: 2021
Subjects: subject: Neutralizing antibody
subject: COVID-19
subject: Convalescent plasma
subject: Plasma donors
subject: DDC 610 / Medicine &amp; health
subject: SARS-CoV-2
subject: COVID-19
subject: Antibodies, Neutralizing
subject: Blood donors
subject: COVID-19; Blood
subject: SARS-CoV-2
subject: COVID-19
subject: Blutspende
subject: Antikörper

description: Background: Convalescent plasma is one of the treatment options for COVID-19 which is currently being investigated in many clinical trials. Understanding of donor and product characteristics is important for optimization of convalescent plasma. Methods: Patients who had recovered from CO­VID-19 were recruited as donors for COVID-19 convalescent plasma (CCP) for a randomized clinical trial of CCP for treatment of severe COVID-19 (CAPSID Trial). Titers of neutralizing antibodies were measured by a plaque-reduction neutralization test (PRNT). Correlation of antibody titers with host factors and evolution of neutralizing antibody titers over time in repeat donors were analysed. Results: A series of 144 donors (41% females, 59% males; median age 40 years) underwent 319 plasmapheresis procedures providing a median collection volume of 850 mL and a mean number of 2.7 therapeutic units per plasmapheresis. The majority of donors had a mild or moderate course of COVID-19. The titers of neutralizing antibodies varied greatly between CCP donors (from &lt;1:20 to &gt;1:640). Donor factors (gender, age, ABO type, body weight) did not correlate significantly with the titer of neutralizing antibodies. We observed a significant positive correlation of neutralization titers with the number of reported COVID-19 symptoms and with the time from SARS-CoV-2 diagnosis to plasmapheresis. Neutralizing antibody levels were stable or increased over time in 58% of repeat CCP donors. Mean titers of neutralizing antibodies of first donation and last donation of repeat CCP donors did not differ significantly (1:86 at first compared to 1:87 at the last donation). There was a significant correlation of neutralizing antibodies measured by PRNT and anti-SARS-CoV-2 IgG and IgA antibodies which were measured by ELISA. CCP donations with an anti-SARS-CoV-2 IgG antibody content above the 25th percentile were substantially enriched for CCP donations with higher neutralizing antibody levels. Conclusion: We demonstrate the feasibility of collection of a large number of CCP products under a harmonized protocol for a randomized clinical trial. Titers of neutralizing antibodies were stable or increased over time in a subgroup of repeat donors. A history of higher number of COVID-19 symptoms and higher levels of anti-SARS-CoV-2 IgG and IgA antibodies in immunoassays can preselect donations with higher neutralizing capacity.