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

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 PRNT₅₀titers 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.