Comparison of antibody response to hepatitis B vaccination in infants with positive or negative maternal hepatitis B e antigen (HBeAg) in cord blood: implication for the role of HBeAg as an immunotolerogen

Abstract

ABSTRACT Hepatitis B e antigen (HBeAg) has been considered to cause immunotolerance to hepatitis B virus (HBV) in newborn infants after fetal HBeAg exposure. This study compared anti-HBs responses to hepatitis B vaccination in infants who were born to HBeAg-positive and -negative mothers respectively, to investigate whether fetal HBeAg exposure may induce immunotolerance to HBV. Totally 265 infants who received recommended neonatal immunoprophylaxis against hepatitis B and had no HBV infection were included. Anti-HBs levels were compared between 124 infants with cord blood positive HBeAg and 141 infants with cord blood negative HBeAg at 7–12 months of age. The infants in two groups had similar age at the follow-up (10.0 ± 2.3 vs 10.1 ± 2.3 months, P = 0.590). Overall, 259 (97.7%) of 265 infants achieved anti-HBs levels (mIU/ml) ≥10 and 6 (2.3%) others had anti-HBs <10. Of 124 HBeAg-positive infants at birth, 46.0%, 39.5%, 12.1%, and 2.4% had anti-HBs levels (mIU/ml) ≥1000, 100–999.9, 10–99.9, and <10, respectively. Of 141 HBeAg-negative infants at birth, 35.5%, 48.9%, 13.5%, and 2.1% showed ≥1000, 100–999.9, 10–99.9, and <10, respectively. The proportions of each anti-HBs level between the two groups were comparable (all P > 0.05). Additionally, the distribution of anti-HBs response levels were also comparable in infants with high and low HBeAg levels (P = 0.818). In conclusions, the fetal HBeAg exposure does not inhibit the antibody response to neonatal hepatitis B vaccination. The data suggest that HBeAg appears not inducing immunotolerance to HBV.