The Relationship Between Gene Heterogeneity Of Hepatitis B Virus And The Interruption Failure Of HBV Vaccines Via Mother-to-infant

Aim:To investigate the relationship between the replication status and mutations in the S and P regions of mothers and their children infected hepatitis B virus(HBV)and the interruption failure of HBV vaccines via mother-to-infant transmission.Methods:Enzyme-linked immunoadsorbent assay(ELISA)and microparticle enzyme immunoassay(MEIA)were applied to serum screen.Nested-polymerase chain reaction(Nested-PCR)or PCR was used to amplify the HBV S and P gene. HBV S,P gene sequence analyzed by the DNASTAR software.Real time-PCR was applied to amplify the copies of samples.Results:(1)HBV DNA positive rate was 60.98%(25/41),83.78%(31/37),60.98% (25/41)in the immunosuccessful mothers and immunofailure mothers and immunofailure children in serum respectively by S gene polymerase chain reaction (PCR)。(2)The mean copies among the children,immunofailure and immunosucessful mothers,by RT-PCR,was 6.65×10~7,4.17×10~7,8.40×10~6 respectively,and the difference was statistically significant(P value 0.023)between immunosuccessful mothers and immunofailure mothers,but are not statistically significant(P value is 0.380)compares immunofailure mothers with children,and the two groups had no linear correlations in copies of serum(P value 0.08).(3)High homology,above 99.5%,was found in HBV gene between matching immunofailure mothers and immunofailure children,and the evolution is high close.(4)Type C is the main genotype in immunofailure and immunosuccessful mothers,and the rate is higher in immunofailure mothers than immunosuccessful mothers(P value 0.071),while there has no difference.(5)Several common amino acids variation sites were found whin "a"determinant group of HBV S gene,G145R,G145A in immunofailure children, G145R,T123A in immunofailure mothers,T126N,T126S,T143N,D144A,D144G immunosucessful mothers.(6)23 sequences from immunofaiure mothers and 9 sequences from immunosuccessful mothers were not found in HBV P gene mutations.Conclusions:(1)High level of serum HBV DNA content is one of high risk factors of the failure of immune blocking of HBV vertical transmission with hepatitis B vaccine. (2)Evolution Analysis of S gene of different HBV trains in immunofailure mothers and children showed that the homology is quite high.(3)Type C was the main genotype in immunofailure and immunosuccessful mothers,but had no significant difference in the interruption failure of HBV vaccines via mother-to-infant transmission.(4)The amino acids variation sites G145R,G145A in immunofailure children and G145R,T123A in immunofailure mothers found in "a" determinant group,we should research further about whether these variant sites were related to the failure of immune blocking.(5)P gene mutations had no relationship with the failure of immune blocking.