Effect of rutin on virus inactivation by AMT in combination with ultraviolet-A irradiation in platelet concentrates

Treatment with psoralens and ultraviolet-A (UVA) irradiation have been found to be effective for virus sterilization of platelet concentrates (PCs). We report here a virus inactivation method using a combination of psoralen derivative 4'-aminomethyl-4,5', 8-trimethylpsoralen (AMT) and UVA irradiation (AMT/UVA). Further, we also investigated the effect of rutin, a radical scavenger, on the inactivation of vesicular stomatitis virus (VSV) as a model virus administered in PCs and platelet functions were investigated. Spiked VSV (about 5log10) in PCs was inactivated by a combination of AMT (50 μg/ml) and 5.2 J/cm2 UVA irradiation in the absence of rutin. To obtain equivalent levels of VSV kill in the presence of 0.35 mM rutin, treatment with 13.0 J/cm2 of UVA irradiation with AMT was performed. When PCs were treated under each condition in which 5log10 VSV was inactivated by AMT/UVA with or without rutin, platelet aggregation function was maintained for more than 80% of untreated platelets. These findings indicate that the presence of rutin during AMT/UVA treatment conferred no beneficial effect. In addition, overnight storage of PCs with AMT induced 40% loss of platelet aggregation in response to 10μM ADP. The findings suggest that UVA irradiation is required immediately after the addition of AMT. (author)