Inactivation of model viruses and bacteria in human fresh frozen plasma using riboflavin and long wave ultraviolet rays

BACKGROUND AND OBJECTIVES Pathogen reduction technologies are among methods to eliminate transfusion transmitted infections. Mirasol method using riboflavin in combination with ultraviolet rays is one of them. The aims of this study were to investigate the effectiveness of Mirasol method to inactivate some model pathogens as well as examination of the sensitivity of plasma proteins after treatment. MATERIALS AND METHODS Riboflavin in 50μM concentration and ultraviolet (365 nm) in three different energy doses (3.6, 7.2, and 10.8 j/cm2) were employed to inactivate model pathogens. Four standard viruses were used in this study including Vesicular Stomatitis Virus (VSV), Herpes Simplex Virus1 (HSV-1), Bovine Viral Diarrhea Virus (BVDV) and Polio Virus. 50% Tissue Culture Infectious Dose (TCID50) and Reed-Muench Methods were used to estimate viruses' titers. E. coli and Staphylococcus aureus were used as bacterial models. Four plasma proteins including factor V, VIII, fibrinogen and antithromin were used to determine their sensitivity to pathogen inactivation treatment. RESULTS The most pathogen reduction titre was determined for 15 minutes irradiation period equal to 10.8 J/cm2 that is corresponding to Log 6.10 for BVDV, Log 6.09 for HSV-1, Log 6.62 for VSV and Log 3.36 for Polio. Bacterial reduction titer was Log 6.94 for E. coli and Log 7.00 for S. aureus. Indicator proteins for plasma activity were determined to be 75% for factor V, 88% for factor VIII, 52% for fibrinogen and 94% for antithrombin. CONCLUSION Results showed that the employed method can inactivate most of the pathogens in fresh frozen plasma. The acceptable activities of selected plasma proteins remained after treatment.