Maternal transmission risk and antibody levels against hepatitis B virus e antigen in pregnant women

SummaryBackgroundThe generation of antibodies (anti-HBe) against hepatitis B virus (HBV) e antigen (HBeAg) often coincides with clinical remission in chronic HBV patients. We aimed to examine the effect of maternal anti-HBe in protection against HBV mother-to-child transmission (MTCT).MethodsA total of 140 chronic HBV-infected pregnant women participated in this study. Before delivery, maternal HBV serological markers and HBV viral load were determined and anti-HBe titers were semi-quantified. Neonatal hepatitis B surface antigen (HBsAg) and HBV-DNA status were determined from cord blood. The children were followed to age 1–3 years.ResultsThe HBV-DNA positive rate in cord blood was 75.61% (31/41) in those who were born to mothers with serum HBV-DNA >106 IU/ml, which was significantly higher than in those who were born to mothers with HBV-DNA <106 IU/ml (3/99, 3.03%; p < 0.0001). However, 10 newborns from mothers with serum HBV-DNA >106 IU/ml had no detectable HBV-DNA in cord blood; anti-HBe was positive with a median titer of 10 (interquartile range 10–55). A total of 84 children who received hepatitis B immune globulin (HBIG) within 12 h after birth and who completed three doses of recombinant HBV vaccination were followed to age 1–3 years (up to May 2014). All 56 children who were born to mothers with serum HBV-DNA levels <106 IU/ml were HBsAg-negative. Five of the 22 children born to anti-HBe-negative mothers with serum HBV-DNA >106 IU/ml acquired an HBsAg-positive status. However, none of the six children who were born to anti-HBe-positive/weak-positive mothers with serum HBV-DNA >106 IU/ml acquired an HBsAg-positive status.ConclusionsThe presence of maternal anti-HBe is protective against HBV MTCT, independent of the maternal serum HBV viral load.