Background: A photochemical treatment (PCT) process has been developed to inactivate pathogens and white blood cells (WBCs) in therapeutic plasma. Process validation studies were performed in three European blood centers under routine operating conditions.
Study design and methods: Each center prepared 30 apheresis and 30 to 36 whole blood-derived plasma units for PCT. Each whole blood-derived plasma unit contained a mixture of two to three matched donations. After removal of pretreatment control samples (control fresh-frozen plasma [C-FFP]), 546 to 635 mL of plasma was treated with 15 mL of 6 mmol per L amotosalen, 3 J per cm(2) UVA treatment, and removal of residual amotosalen with a compound adsorption device. After processing, plasma samples (PCT-FFP) were withdrawn, frozen at -60 degrees C within 8 hours of collection, and assayed for coagulation factors and residual amotosalen.
Results: A total of 186 units of plasma were processed. The mean prothrombin time (12.2 +/- 0.6 sec) and activated partial thromboplastin time (32.1 +/- 3.2 sec) of PCT-FFP were slightly prolonged compared to C-FFP. Fibrinogen and Factor (F)VIII were most sensitive to PCT (26% mean reduction). PCT-FFP, however, retained sufficient levels of fibrinogen (217 +/- 43 mg/dL) and FVIII (97 +/- 29 IU/dL) for therapeutic plasma. Mean levels of FII, FV, FVII, F IX, FX, FXI, and FXIII in PCT-FFP were comparable to C-FFP (81%-97% retention of activity). Antithrombotic proteins were not significantly affected by PCT with retention ranging between 83 and 97 percent. Mean residual amotosalen levels were 0.6 +/- 0.1 micromol per L.
Conclusion: Process validation studies in three European centers demonstrated retention of coagulation factors in PCT-FFP within the required European and respective national standards for therapeutic plasma.