Study on the Cellular Molecular Mechanism of Intrauterine Transmission of Hepatitis B Virus

Objective: To study intrauterine transmission of HBV and its cellular molecular mechanism and influence on the fetus. Methods.. A total of 46 coses of pregnant women who suffered from HBV were divided into HBeAg ( + ) and HBeAg ( -) groups. HBV-DNA in serum and peripheral blood mononuclear cells (PBMC-) of 46 cases of pregnant women before delivery was detected by polymerase chain reaction (PCR). After placenta being delivery, HBV-DNA in serum and cord blood mononuclear cells (CBMC) was also detected by PCR. Results.. The total of positive rates of HBV-DNA in serum and PBMC of pregnant women with hepatitis B were 69. 57% (32/46) and 41. 30% (19/46). The positive rates of HBV-DNA in serum of cord blood and CBMC were 56. 52%(26/46) and 21. 74% (10/46) respectively. Among them, the positive rates of HBV-DNA in serum and PBMC of pregnant women with HBeAg ( + ) were 100. 00% (25/25) and 60. 00% (15/25) respectively. The positive rates of HBV-DNA in serum of cord blood and CBMC were 88. 00% (22/25) and 32. 00% (8/25) respectively. The positive rates of HBV-DNA in serum and PBMC of pregnant women with HBeAg (-) were 33. 33% (7/21) and 19.05% (4/21) respectively. The positive rates of HBV-DNA in serum of cord blood and CBMC were 19. 05%(4/21) and 9. 52% (2/21) respectively. The positive rates of HBV-DNA in serum of cord blood and CBMC of newborns were higher in the group of pregnant women with HBeAg ( + ) than those in the group of pregnant women with HBeAg ( -) (P<0. 01 and P<0. 05). There was no HBV-DNA in serum, PBMC and CBMC of normal pregnant women and normal neonates. Conclusion: The intrauterine transmission of HBV can be existent and its transmission way not only can be induced by serum but also can be induced by PBMC. The way of intrauterine transmission of HBV induced by PBMC was concealed. The dangerous possibility of intrauterine transmission is higher in the pregnant women with HBeAg (+) than that in the group of pregnant women with HBeAg ( -).

Impact of HBV replication in peripheral blood mononuclear cell on HBV intrauterine transmission

This study determined the effect of hepatitis B virus （HBV） replication in peripheral blood mononuclear cell （PBMC） from HBsAg-positive mothers on HBV intrauterine transmission. A total of 150 HBsAg- positive mothers and their neonates were recruited in this study. Within 24 h after birth, HBV serological markers, serum HBV DNA, PBMC HBV relaxed circular DNA （rcDNA）, and covalently closed circular DNA （cccDNA） were measured in the HBsAg-positive mothers and their neonates before passive-active immune prophylaxis. The relationship between HBV replication in PBMC and HBV intrauterine transmission was examined through Chi- square test and logistic regression. The rate of HBV intrauterine transmission was 8.00% （12/150） in the 150 neonates born to HBsAg-positive mothers. The positivities of PBMC HBV rcDNA and cceDNA in the HBsAg- positive mothers were 36.67% （55/150） and 10% （15/150）, respectively. Maternal PBMC HBV cccDNA was a risk factor of HBV intrauterine transmission （OR = 6.003, 95% Ch 1.249-28.855）. Maternal serum HBeAg was a risk factor of PBMC HBV rcDNA （OR = 3.896, 95% CI： 1.929-7.876） and PBMC HBV cccDNA （OR = 3.74, 95% CI： 1.186--11.793） in the HBsAg-positive mothers. Administration of hepatitis B immune globulin was a protective factor ofPBMC HBV cccDNA （OR = 0.312, 95% CI： 0.102-0.954） during pregnancy. The positivity ofPBMC HBV rcDNA was related to that of cccDNA in the HBsAg-positive mothers （Zz= 5.087, P = 0.024）. This study suggests that PBMC is a reservoir of HBV and an extrahepatic site for virus replication and plays a critical role in HBV intrauterine transmission.

Relationship between heterogeneity of HBV preS/S gene and intrauter-ine transmission

Objective: To study the relationship of the mutation of HBV preS/S gene in HBsAg carrying pregnant women and intrauterine transmission. Methods: Polymerase chain reaction (PCR) was used to amplify HBV preS/S gene from sera of 8 HBsAg carrying pregnant women, 4 women's neonates infected with HBV, and the other's neonates non-infected with. The PCR products were cloned and 5 clones were chosen from every woman for DNA sequencing. Results: Heterogeneity of HBV preS/S gene in HBsAg carrying pregnant women having intrauterine transmission was much higher than that from having not intrauterine transmission, and the divergence rate of nucleotide sequences also higher strikingly. Conclusion: High heterogeneity of HBV preS/S gene of HBsAg positive pregnant women may be relative to high rate of intrauterine transmis-sion