[Effect of intrauterine hepatitis B virus infection on hepatitis B vaccine inoculation in newborns].

OBJECTIVES: To study the effect and the mechanism of peripheral blood nuclear cells (PBMC) invaded by hepatitis B virus (HBV) on the artificial immunization in newborns. METHODS: Fifty-two newborns, whose mothers were hepatitis B surface antigen (HBsAg) positive, were immunized with hepatitis B immunoglobulin and hepatitis B vaccine (HBVac), and then followed for 7 months. The newborns' serum and PBMC HBV DNA was detected by nested-PCR, hepatitis B surface antibody (HBsAb) was tested with solid phase radioimmunoassay. PBMC from newborn were incubated with PHA and HBsAg. The supernatant interleukin 2 (IL-2) level was measured by enzyme linked immununosorbent assay (ELISA). RESULTS: The rate of vaccination failure was higher in the infants with PBMC HBV DNA positive than those with negative (P < 0.05). The supernatant IL-2 level was lower in the former than that in the latter and the control (P < 0.05). The level of IL-2 in the immunization failure newborns was lower than that in the vaccination success and the control (P < 0.05). CONCLUSIONS: The intrauterine PBMC HBV invasion is one of the important causes of vaccination failure in the newborns. PBMC IL-2 autocrine down regulation is closely related to HBV invasion, that may lead to the failure of HBVac inoculation in the newborns.