Plasma treated with amotosalen and ultraviolet A light retains activity for hemostasis after 5 days post‐thaw storage at 1 to 6oC

BACKGROUND Plasma thawed and stored at 1 to 6°C for up to 5 days (thawed plasma [TP]) provides rapid availability in emergencies and reduces plasma waste, but it carries risks of coagulation factor loss or activation, bacterial outgrowth, and viral contamination. We characterized changes in amotosalen/ultraviolet A (UVA) light pathogen-reduced, fresh-frozen plasma (FFP) and plasma frozen within 24 hours (PF24) with post-thaw storage. STUDY DESIGN AND METHODS Amotosalen/UVA light-treated FFP and PF24 were thawed after approximately 3 to more than 12 months of frozen storage and held at 1 to 6°C for 5 days. Global assessments of coagulation and hemostatic, antithrombotic, and activation markers indicative of function were assessed. RESULTS Day 5, thawed amotosalen/UVA light-treated FFP and PF24 contained levels of Factors II, V, VIII, IX, X, von Willebrand factor ristocetin cofactor (vWF:RCo), fibrinogen, antithrombin III (ATIII), protein C, and protein S similar to the levels measured in Day 5 TP, as described in the Circular of Information. Thrombin generation was robust on Day 5 (amotosalen/UVA: FFP = 1866 ± 402 nM/minute; PF24 = 1800 ± 277 nM/minute). Most factor activities on Day 5, including von Willebrand factor-cleaving protease (ADAMTS-13), were more than 90% of Day 0 values, except for known labile Factors V and VIII and protein S. All units contained greater than 0.4 IU/mL protein S and α2 plasmin inhibitor on Day 5. Global functional indices, including thrombin-antithrombin complexes, nonactivated thromboplastin time, and thrombin-generation peak height, did not indicate activation of the coagulation cascade, although isolated units showed raised levels of Factor VIIa and Complement 3a. CONCLUSION Amotosalen/UVA light-treated FFP and PF24 demonstrated retention of procoagulant and antithrombotic activity after 5 days post-thaw storage at 1 to 6°C.