Detection Of HPgV-2 In Healthy Blood Donors And Multiple Blood Transfusion Recipients:Implications To Blood Safety

Background In 2015,a novel blood-borne human pegivirus,human pegivirus type 2(HPgV-2),a positive strand RNA virus was discovered by Kapoor etc.in the USA.HPgV-2 is mainly coinfected with hepatitis C virus(HCV),especially in HCV combined with AIDS(HCV/HIV)populations.HPgV-2 shares features of both hepatitis C virus(HCV)and human pegivirus(HPgV;formerly called GB virus C or hepatitis G virus).However,phylogenetic analysis showed that HPgV-2 belongs to the genus of Pegivirus rather than Hepacivirus of the family Flaviviridae.In order to distinguish it from human pegivirus(HPgV),it was named human pegivirus type II(HPgV-2).[1].Objective To investigate the detection and prevalence of HPgV-2 in blood donors,transfusion recipients and hemophilia patients,and discuss the change of ALT level in patients infected HCV coinfection with HPgV-2,and its implication to blood safety.Methods Serum samples of volunteer blood donors,transfusion recipients,etc.were collected and screened for anti-HPgV-2 antibodies,HPgV-2 RNA,anti-HCV and HBsAg/HBV-DNA using ELISA and PCR or RT-PCR,respectively.Phylogenetic analysis of near full length genome sequences and NS3 genes of Pegiviruses and Hepaciviruses were performed by using MEGA(version 6)software and the OD results of anti-HPgV-2 antibody were analyzed by GraphPad Prism 5.Using case-control study to analysis the varies of ATL and HCV viral load(HCV-VL).Results 1)Anti-HPgV-2 antibody,but no viremia was detected in 0.28%(3/1060)healthy blood donors who are negative for HCV、HBV and HIV,as well as 1 out of 500 HBV-infected blood donors.However,the prevalence of anti-HPgV-2 and HPgV-2 RNA was 1.21%(17/1402)and 0.36%(5/1402)in the blood donors infected with HCV(RNA+/Ab+),indicating tight correlation between HPgV-2 and HCV infection(x2=13.78,P=0.004).2)Anti-HPgV-2 was not detected in 570 multiple transfusion receipients and detected in only one sample(0.40%)out of the 248 serum samples from hemophilia patients.3)The nucleotity identity of 97.11%was found among the 5 HPgV-2 NS3 fragments identified in our study whereas 96.53%of identity was obtained between the sequences from China and worldwide.4)comparative analysis showed that level of ALT and HCV-VL in HCV patients coinfection with HPgV-2 did not increase.On the contrary,we found that there was a slight decreasing for ALT.Conclusions Our preliminary results indicate that HPgV-2 infection is less frequent in healthy blood donors and transfusion recipients.HPgV-2 is mainly co-infected with HCV.The infection of HPgV-2 does not raise the damage of liver or increase the HCV viral load.Transfusion transmission of HPgV-2 may not be common.Therefore,HPgV-2 may not be a threat to blood safety.