The e antigen and vertical transmission of hepatitis B surface antigen.

The relationship of e antigen (eAg) and its antibody (anti-e) to vertical transmission of hepatitis B surface antigen (HBsAg) from chronic asymptomatic HBsAg carrier women to their children was investigated in Taiwan. Sera from 20 of the 62 women studied were positive for eAg (32%); serum from only one woman was positive for anti-e (2%). A total of 85% of the babies born to eAg positive mothers became HBsAg carriers, while only 31% of the babies became carriers when the mother was eAg negative. Maternal e antigenemia correlated with a high HBsAg titer, and both parameters were equally good predictors of vertical transmission.