Molecular Virological Characteristics Of Hepatitis D Virus And Hepatitis B Virus Dual-Infection

Background and objective:Hepatitis D virus(HDV)is a satellite virus of hepatitis B virus(HBV).Theoretically,all hepatitis B patients should be screened for hepatitis D infection.However,due to high burden of hepatitis B infection,insufficient screening of HDV,and HDV prevalence varies according to geography,it is difficult to estimate the certain prevalence rate of hepatitis D infection.After HDV entries hepatocytes,small hepatitis D antigen(S-HDAg)is translated to promote HDV replication.After a period of replication,HDV uses host enzyme to edit RNA,and is converted into an edited-HDV.The latter produces Large Hepatitis D antigen(L-HDAg),which inhibits HDV replication and promotes HDV assembly and release.Both S-HDAg and LHDAg can inhibit the replication of HBV through various mechanisms.Edited-HDV can release from and entry into hepatocytes,but when edited-HDV momo infects hepatocytes,it can’t replicate and establish hepatitis D infection.The L-HDAg producted by edited-HDV may prevent HBV or original-HDV infection.One of the objectives was to study the prevalence and the characteristics of molecular virology of HDV in hepatitis B patients.We used these results,to find a more reasonable screening strategy.The other objectives was to find the effects of edited-HDV infection on other hepatitis viruses,exploring its application prospects in the treatment of viral hepatitis.Methods:5594 serum samples of hepatitis B patients were collected in Jilin Province,hepatitis B surface antigen(HBsAg),HBV DNA,anti-HDV,and HDV RNA were detected,and study data were performed statistical analysis.The proportion of editedHDV to total HDV in the serums of patients with hepatitis D were analyzed by gene sequencing.Using in vitro experiments and molecular biology methods,hepatocytes were infected with virus through the corresponding virus whole genome plasmid,to investigate the effects of edited-HDV infection on other hepatitis viruses.Results:In the hepatitis B patients of Jilin Province,the positive rate of anti-HDV was about 3.6%(3.2-4.2%),and the positive rate of HDV RNA was about 1.2%(0.91.5%).The screening positive rates of HDVRNA in male and female hepatitis B patients were similar(1.2%vs 1.1%,P>0.05).The screening positive rate of HDV RNA of 51-80 years old hepatitis B patients was higher than that of 31-50 years old patients(2.1%vs 0.2%,P<0.05),87.7%of hepatitis D patients were between 51 to 70 years old.The HBsAg quantity of HDV-resolved patients(anti-HDV positive and HDV RNA negtive)was lower than that of hepatitis D patients(65.83 IU/mL vs 892.90 IU/mL,P<0.05).The HBV DNA quantity of hepatitis D patients was lower than HBV mono-infected patients(18.6 IU/mL vs 338 IU/mL,P<0.05),screening for HDV infection is more likely to yield positive results in hepatitis B patients with lower HBV DNA level,95.2%of hepatitis D patients had HBV DNA quantity below 2000 IU/mL.The anti-HDV absorbance of hepatitis D patients was higher than that of HDV-resolved patients(2.219 vs 1.397,P<0.05),those with higher anti-HDV levels were more likely to test positive for HDV RNA.A weak correlation was observed between HBsAg and anti-HDV in hepatitis D patients(r=0.256,P=0.043).In the serum of 83.3%of hepatitis D patients,edited-HDV accounts for 35%43%of the total HDV.In vitro experiments,when the initial proportion of editedHDV was more than 50%,HDV replication was lesser compared to all original-HDV group(P<0.05);but HBV replication remained unchange compared to the group that didn’t transfect HDV(P>0.05).In HDV mono-infection,there was a negative correlation between the initial proportion of edited-HDV and HDV RNA level(r=0.857,P=0.029);but in HBV-HDV co-infection,there was no correlation between the initial proportion of edited-HDV and HDV RNA level(r=-0.790,P=0.061),and no correlation between the initial proportion of edited-HDV and HBV DNA level too(r=-0.547,P=0.262).Edited-HDV added to hepatocytes in advance can reduce the replication of HBV entered subsequently(0.56 vs 1.00,P<0.05),but can’t affect the replication of original-HDV entered subsequently(0.99 vs 1.00,P>0.05).After entering hepatocytes that were already infected with HBV,edited-HDV increased HBV replication(1.46 vs 1.00,P<0.05).Conclutions:Among the hepatitis B patients of Jilin Province,the positive rates of anti-HDV and HDV RNA were about 3.6%and 1.2%,respectively.Hepatitis B patients over 50 years old,or HBV DNA quantity less than 2000 IU/mL,should be screened for hepatitis D infection.Patients with higher anti-HDV levels are more likely to test positive for HDV RNA.In the serum of most hepatitis D patients,edited-HDV accounted for 35%-43%of the total HDV.In vitro experiments,when the initial proportion of edited-HDV was more than 50%,edited-HDV could inhibit the replication of original-HDV that entered simultaneously,but had no effect on the replication of HBV that entered simultaneously.Edited-HDV in hepatocytes might prevent HBV infection,but couldn’t prevent primitive original-HDV infection.