(P-CB-13) Pathogen Reduction of Whole Blood with Acriflavine

The safety of blood transfusion remains an important challenge for public health. Several UV and photosensitizer-based pathogen reduction technologies have been developed for blood components but not for whole blood. Acriflavine (ACF) exhibits broad antibacterial, antiviral and antiparasitic activity by effectively intercalating into DNA. Here we explore if the broad activity of ACF can be used for pathogen reduction in whole blood.

Study

Design/Methods:

Bacteria (10⁸ colony forming units of E. coli) were added to 2 ml of whole blood, treated with ACF in 6-well plates for log reduction assay. For in vitro vaccinia viral inactivation assays, the viral stocks were added to 2 ml of the DMEM medium including 100 uM ACF and incubated for 14 hours at room temperature. The mixture of virus samples was then added to Vero cells in a 96 well plate. The log reduction in viral titer was calculated from each apparent TCID₅₀ titer. Hemolysis was measured by absorbance of released hemoglobin in the supernatants after ACF treatment in 6-well plates at 576 nm. Samples were taken from whole blood bags mixed with ACF and treated for 24 hours at 4^oC for the analysis of RBC counts, hematocrit, hemoglobin, pH, and efficiency of blood coagulation assessed by TEG 6s Hemostasis Analyzer. All tests were applied to four independent whole blood units except for the hemolysis which was tested on two units.

Results/Findings:

ACF (100uM) added to whole blood inoculated with E. coli in 6-well plates at room temperature, produced 7.4 log reduction of bacteria after 24 hours while hemolysis was 0.3%.  Whole blood treated with 100 uM of ACF for 24 hours at 4^oC in gas permeable storage bags had no significant differences in RBC and platelet counts, hematocrit, hemoglobin, and pH between the control and ACF treated samples (Table 1). In viscoelastic testing, there were no significant differences in any of the measured parameters (Table 1) between control and 100 uM ACF treated samples.  In a separate preliminary experiment, ACF (100 uM) produced 4.6 log reduction of vaccinia virus suspended in cell media.

Conclusions:

Acriflavine can inactivate representative bacteria and virus. Whole blood treated with ACF at room temperature maintained low levels of hemolysis, and hematologic and viscoelastic parameters similar to control after 24 hours of treatment.  These results provide early proof of a principle for ACF as a pathogen reduction method for whole blood.  Additional studies for virus reduction, plasma, and platelet function tests after ACF treatment are under way.

This abstract reflects the views of the authors and should not be construed to represent FDA's views or policies.