Study on a antepartum immunoprophylaxis to interrupt the transmission of hepatitis B virus from mother to infant / 中华传染病杂志

ABSTRACT

Objective To investigate the efficacy and the mechanism of different dose hepatitis B immunoglohulin(HBIG)on prevention of HBV intrauterine infection and HBV S gene mutation. Methods HBV carrier mothers were randomly divided into three groups.Eighty-one HBsAg carrier pregnant women were divided into HBIG A group.HBIG B group and control group.Each subject in the HBIG A group received 200 U or 400 U(for HBsAg and HBeAg double positive carrier)intra muscularly at 3,2,1 month before delivery.Each subject in the HBIG B group received 200 U intra muscularly at 3,2,1 month before delivery.The subjects in the control group did not receive any treatment.Maternal blood samples were taken before HBIG injection and at delivery.Neonatal blood samples of all newborn infants after birth were taken before immunopropbylaxis.Their sera were ob tained to test HBV markers by enzyme immunoassay(EIA)and HBV DNA by fluorescence quantita- tive polymerase chain reaction(FQ-PCR),then to amplify and sequence HBV S gene region.Results The rate of HBV intrauterine infection in the HBIG group(14.5%)was lower than that in the control group(35.7%)(X~2=4.896,P=0.027).The rate of HBV intrauterine infection of newborns from HBsAg and HBeAg double positive carrier mother in the HBIG A group(37.5%)were lower than control group(100.0%)(X~2=7.273,P=0.007),while the rate was no different in the HBIG B group(71.5%)and the control group(X~2=2.637,P=0.104).Maternal HBsAg titer and HBV DNA level were of no difference among three groups before HBIG injection.Maternal HBsAg titers and HBV DNA levels of the HBIG A group were lower than those of the HBIG B group and the con- trol group at delivery.Among the 26 neonatal serum samples in the HBIG A group,10(38.5%)were positive for anti-HBs,while in the HBIG B group and in the control group,no neonatal serum sam- ples was positive.There was no significant difference of nucleotide and amino acid changes in the S gene between the HBIG group and the control group.Conclusions HBV infection in the uterus may be interrupted by injection HBIG intramuscularly before delivery.More efficacy would be found using variable HBIG dose according to different HBV virema and must be once more again injected just he- fore one week of delivery;anti-HBs transported to the fetus via the placenta and it's may be the im- portant mechanism of HBIG prevention.Asymptomatic HBsAg carrier mother received injections of HBIG before delivery should not influence HBV S gene mutation.Gene mutation of HBV is not the main factor in intrauterine transmission of HBV.