Perinatal Hepatitis B Virus Infection: Viral Factors in the Mechanism of Perinatal Immunoprophylaxis Failure

Kim, Jong Hyun

Abstract

Perinatal hepatitis B virus(HBV) infection may occur despite combined immunoprophylaxis with hepatitis B immunoglobulin and vaccines. Although the mechanism of perinatal prophylaxis still has been obscure, it could be due to:in utero infection; host factors as the personal immunological differences of HLA or cytokine gene; viral factors as a high maternal HBV-DNA level or the presence of surface gene variants; or other factors as the differences of composition, quality, dosage, frequencies, timing and injection site of HBV vaccine or immunoglobulin. To investigate the clinical significance of variant in HBV surface gene in Korea, DNA sequence analysis of the major hydrophilic region was performed and reviewed the related articles. The variant rate observed in perinatal HBV immunoprophylaxis failure children in comparison to other studies was 6.45% versus 14-40%. And perinatal infection could be prevented by immunoprophylaxis in children, even though mothers had infection with variants in HBV surface gene. These findings suggest that the variants on the surface gene are not playing an important role in perinatal immunoprophylaxis failure in Korea. Also, a fact that the higher maternal DNA level was strongly associated with immunoprophylaxis failure was demonstrated. Therefore, the conditions, like maternal viral composition, the degree of maternal DNA level, the status of host immune system should be associated with the outcome of immunoprophylaxis in perinatal infection simultaneously.