Paired study on hepatitis B virus S gene mutation in immunoprophylaxis failure to prevent HBV vertical transmission / 中国病理生理杂志

ABSTRACT

AIM:To explore the characteristics of hepatitis B virus S gene mutation in the vertical transmission after active and passive vaccination .METHODS:Fifteen cases of immunoprophylaxis failure were enrolled in the study . HBV S gene (including pres-S and S) from the mothers, newborns before active and passive vaccination and 7-month-old infants with immunoprophylaxis failure were detected by PCR amplification .The characteristics of HBV S gene mutation were compared among the 3 groups.RESULTS: The genotype of HBV in the newborns and the infants was the same as that in the mothers .The frequencies of mutation in the 2 fragments of the HBV S gene had no significant difference between the 3 groups.The homology tree model based on HBV S gene was analyzed in the 3 groups, in which every group had their own cluster.There were 15 different mutation sites between 7 pairs of mothers and newborns .There were 3 different muta-tion sites between 3 pairs of newborns and infants (nt273A→A/G, nt512C→C/T and nt1139C→A), among which the first 2 were located in the S gene region but not in the “a” determinant , and the latter was located in the overlap region of S and X genes .There were 25 different mutation sites between 9 pairs of mothers and infants , but only 1 case had a differ-ent mutation site between the mother , newborn and infant .CONCLUSION: The HBV species in newborns and infants with immunoprophylaxis failure were transmitted from the mothers .The mutations in the HBV S gene with immunoprophy-laxis failure happened before and after active and passive vaccination , mainly before vaccination .The relationship between HBV S gene mutations and immunoprophylaxis failure should be further explored .