Plasma constituent integrity in pre-storage vs. post-storage riboflavin and UV-light treatment--a comparative study

Treatment of fresh frozen plasma (FFP) by riboflavin (RB) and ultraviolet (UV) light inhibits nucleic acid replication, leading to inactivation of white blood cells (WBCs) and pathogens. The goal of this study was to compare the effects of pathogen reduction technology (PRT) treatment on the plasma protein content based on biochemical, immune and hemostatic characteristics in "typical" pre-storage vs. post-storage PRT-treatment setting. Following whole blood centrifugation, separated plasma units were: (a) inactivated and frozen (pre-storage setting or control group [CG]) or (b) immediately frozen (post-storage setting or study group [SG]) afterward thawed, inactivated and stored at -40 ± 5°C (cryostorage). Plasma units were inactivated by the Mirasol PRT system (TerumoBCT, USA). Using multi-laboratory techniques and equipments, biochemistry (Advia 1800; Siemens, Germany), IgM, IgG and IgA, complement components C3 and C4 (BNA II nefelometer analyzer; Siemens, Germany), as well as CH50 activity (Behring coagulation timer; Siemens, Germany) were investigated. Procoagulant and inhibitor factors, such as antithrombin-III (AT-III), and protein C (PC) were determined by BCS XP Coagulation system (Siemens, Germany). There were neither significant changes in final protein levels, nor any differences in plasma immunoglobulin levels investigated. In the final samples CH50 activity was reduced in both investigated groups. The plasma concentration of the complement C3 following post-storage treatment was significantly (p<0.05) higher than in pre-storage setting. There was a trend of depletion of procoagulant activities in both, pre-storage and post-storage PRT-treatment (initial vs. final values), but there were no significant differences between two groups. Results confirmed that AT-III was significantly higher after post-storage inactivation. In conclusion, this study confirmed that there were not clinically relevant intergroup (pre-storage vs. post-storage PRT-treatment) differences in plasma constituent levels. Post-storage treated FFP remains, protein quantity, and activity well, and therefore can be used in clinical practice. Previously cryostored or quarantine FFP units (despite the reduced quarantine period after NAT/PCR testing) could be safely and effectively inactivated, directly prior to clinical application.