Background and objectives: Photochemical treatment (PCT) based on amotosalen and ultraviolet A light (UVA) demonstrated a wide range of pathogen inactivation. However, coagulation proteins are affected by this treatment. The aim of this study was to evaluate the coagulation parameters in apheresis plasma units after thawing and processing by PCT.
Materials and methods: Thirty apheresis plasma units were rapidly frozen at </= -30 degrees C after collection. Plasma units were thawed after 7 days for PCT with amotosalen and UVA light. Treated apheresis units were refrozen and stored at </= -30 degrees C for 1 month. Samples were collected for each plasma units at several times of process. Coagulation times (prothrombin time, activated partial thromboplastin time), coagulation factors (fibrinogen, Factor [F] II, FV, FVII, FVIII, FIX, FX, FXI), prothrombin fragments 1 and 2, antithrombotic proteins (protein C, protein S, antithrombin) and total protein content were measured. Functionality of ADAMTS-13 was also tested.
Results: After thawing, coagulation times were slightly increased and a decrease of FV, FVIII and protein C activity was found. The mean recovery for all proteins, except one, ranged from 81% to 97% of the baseline activity in plasma units after thawing and PCT. FVIII was more affected with a mean recovery of 69 +/- 8%. ADAMTS-13 function was also preserved after the whole process. The effect of an additional 1-month frozen storage on coagulation parameters was minimum.
Conclusion: Coagulation protein levels after thawing and processing of plasma by PCT with amotosalen and UVA were preserved well in the physiological ranges.