Preservation of neutralizing antibody function in COVID-19 convalescent plasma treated using a riboflavin and ultraviolet light-based pathogen reduction technology

Yonemura, S.; Hartson, L.; Dutt, T.; Henao Tamayo, M.; Goodrich, R.; Marschner, S.

Background and Objective: Convalescent plasma (CP) has been embraced as a safe therapeutic option for coronavirus disease 2019 (COVID-19) while other treatments are developed. However, transfusion-transmitted disease is a risk, particularly in regions with high endemic prevalence of transfusion-transmissible diseases. Pathogen reduction can mitigate this risk; thus, the objective of this study was to evaluate the effect of riboflavin and ultraviolet light (R+UV) pathogen reduction technology on the functional properties of CCP. Materials and Methods: CCP units (n = 6) from recovered COVID-19 research donors were treated with R+UV. Pre- and post-treatment samples were tested for coagulation factor and immunoglobulin retention. Antibody binding to spike protein receptor binding domain (RBD), S1, and S2 epitopes of SARS-CoV-2 was assessed by ELISA. Neutralizing antibody (nAb) function was assessed by pseudovirus reporter viral particle neutralization (RVPN) assay and plaque reduction neutralization test (PRNT). Results: Mean retention of coagulation factors was [≥] 70% while retention of immunoglobulins was 100%. Starting nAb titers were low, but PRNT50 titers did not differ between pre- and post-treatment samples. No statistically significant differences were detected in levels of IgG (P [≥] 0.3665) and IgM (P [≥] 0.1208) antibodies to RBD, S1, and S2 proteins before and after treatment. Conclusion: R+UV PRT effects on coagulation factors were similar to previous reports, but no significant effects were observed on immunoglobulin concentration and antibody function. SARS-CoV-2 nAb function in COVID-19 convalescent plasma is conserved following R+UV PRT treatment.