Background and Aims Seroconversion of HBeAg to anti-HBe is associated with lower viral load and liver diseases. The purpose of this study was to assess the seroconversion rate of HBeAg to anti-HBe in children who acquired HBV infection during childhood period.

Methods From September 1990 to December 2010, 139 HBeAg positive children were followed up. Eighty-one subjects were failure of Hepatitis B immune globulin (HBIG) and hepatitis B vaccination at birth and 58 children < 10 years who were born before 1990 and did not receive HBIG and vaccine. HBsAg, HBeAg, anti-HBs and anti-HBe was assessed every six months.

Results Sixty two (44.6%) cases were males and 77 (55.4%) were females. Mean duration of follow-up was 18±6.6 years. Twenty-four (17.3%) mothers were HBeAg positive and 115 (82.7%) anti-HBe positive. Eighty-two (59%) children became anti-HBe positive. Seroconversion rates in the first, second and third decades were 25%, 63.4% and 70.5%, respectively (p=0.001). The children of anti-HBe positive mothers had higher seroconversion rate than the HBeAg positive mothers (75% versus 33.9%, p=0.0001). Time to seroconversion rates in children born to HBeAg positive mothers was similar to those born to anti-HBe positive mothers (HR=1.03, p=0.973). Time to seroconversion rates in children who received hepatitis B vaccine and HBIG was higher than those who did not (HR=6.35, p=0001).

Conclusions HBeAg seroconversion in the second and the third decades were higher than the first decade. Children born to anti-HBeAg positive mothers and those who received HBIG and hepatitis B vaccine had higher seroconversion rates.