RESUMO
Objective:To discuss the passive immunity effect and mechanism of HBIG injections to matrix to block the mother-to-child vertical transmission of HBV. Methods:94 cases of patients with chronic viral hepatitis were selected and divided into 3 groups randomly. 31 cases of control group were given no HBIG intervention,while 31 cases of baby intervention ( BBI) group were given HBIG injection in 6h of birth,and 32 cases of infant & mom intervention ( IMI) group were given HBIG injection respectively in 28,32,36 weeks of gestation and 6h of birth. Further more,all newborns were vaccinated against hepatitis B in 0,1 and 6 months,after the last vaccination,peripheral blood of the children were extracted and detected for HBV markers,HBV-DNA and immune function. Results:There were significant difference (P<0. 05) in neonatal HBeAg,HBsAg and HBV-DNA positive rate for the three groups,with Control group got the highest while IMI group got the lowest;and there are also significant differences (P<0. 05) HBeAb positive rate,with Control group got the lowest while IMI group got the highest. We also found that the complement (C3,C4) levels and T cell subtypes (CD3+,CD4+,CD8+) count of the three groups of newborns had significant differences too(P<0. 05),with Control group got the lowest while IMI group got the highest;in terms of immunoglobulin,both the IMI and BBI group were higher in IgG and IgM level (P<0. 05), while there was no obvious difference in IgA between groups (P<0. 05). Conclusion:Maternal HBIG injections can effectively activate the maternal humoral immunity and cellular immunity,resulting in the decrease of HBV. It can also improve newborn′s antigen-antibody response and relieve T lymphocytes loss induced by antiviral consumption through placenta,which may play great role in the passive im-munity mechanism of blocking mother-to-fetus transmission.