Establishment of culture systems for G enotypes 3 and 4 hepatitis E virus ( HEV ) obtained from human blood and application of HEV inactivation using a pathogen reduction technology system

Background It has been demonstrated that the hepatitis E virus ( HEV ) can be transmitted via blood transfusion, and the risk of HEV transmission via transfusion has become a major global concern. An HEV culture system for blood‐derived HEV has been sought to obtain valuable knowledge of the virus and the risk of HEV infection through blood products. Study Design and Methods We endeavored to establish an HEV culture system using RNA ‐positive blood specimens for G enotypes ( G ) 3 and 4 and applied this system to evaluate tissue culture infectious dose ( TCID ). We applied this method to investigate the potential of the M irasol pathogen reduction technology ( PRT ) system ( T erumo BCT ) to inactivate live HEV in contaminated platelet samples ( PLT s). PLT s were spiked with cultured HEV G 3 or G 4 and then treated with the M irasol PRT system. PLT s were examined before and after the treatment for HEV load using TCID titration. Results We successfully established two strains for HEV production: the JRC ‐ HE 3 strain for G 3 and the UA 1 strain for G 4. The M irasol PRT system expressed more than 3 log inactivation for JRC ‐ HE 3 and more than 2 log inactivation for UA 1. Conclusion The M irasol PRT system inactivated greater than 2 to 3 logs of live HEV in PLT s and can potentially be used to lower the possibility of blood‐borne HEV transmission. The G 3 and G 4 HEV inocula identified in this study and the hepatoma cell culture system provide a new means to assess HEV infectious titer and to evaluate other pathogen reduction strategies.