The Effects of Ultraviolet Light and Riboflavin on Inactivation of Viruses and the Quality of Platelet Concentrates at Laboratory Scale

Background: This study investigated the effects of Riboflavin (RB) combined with different doses of UV on Platelet Concentrate (PC) which was infected by three models of virus. Platelet quality after treatment was also assessed. Methods: Three models of virus used in this study were Vesicular Stomatitis Virus (VSV), Herpes Simplex Virus (HSV), and Polio virus, which were added to PC. After photochemical treatment with RB and UV light, residual viral infectivity was titrated using 50% Tissue Culture Infective Dose (TCID50)/ml. This treatment was done with concentration of 50 μM of RB and different doses of UV light (0.24, 0.48, 0.97, 1.29 J/cm 2). Platelet quality was assessed by measuring pH, Lactate Dehydrogenase (LDH), MTT assay and cell count after treatments and during 4 days of storage against control groups. Results: Concentration of 50 μM RB with combination of 1.29 J/cm 2 dose of UV resulted in the highest titer reduction of VSV (4 log 10) and HSV (4.26 log10) and lowest titer reduction of Polio virus (2.6 log10). No significant difference was observed between different doses in comparison with control groups. In all treatment groups, the storage stability of platelets in PC was in the acceptable range in comparison with control group. Conclusion: This study indicated that RB/UV treatment was a promising pathogen reduction technique in PC and had limited effects on platelet quality. However, further optimization of this method is necessary to deal with blood-borne viruses like nonenveloped viruses.