Natural history of chronic hepatitis B virus infection in children of different ethnic origins: A cohort study with up to 12 years' follow-up in Northern Greece

AIM: To investigate the mode of transmission and the natural history of chronic hepatitis B virus (HBV) infection in children of different ethnicities in Greece. This study was part of the Interreg I-II EC project. PATIENTS AND METHODS: One hundred seventy-three hepatitis B surface antigen (HBsAg)(+) carriers, median age 6.9 (5-12) y, were prospectively followed-up for a mean period of 5.3 (1-12) y for serological markers of HBV infection, serum alanine aminotransferase (ALT), HBV-DNA, α-fetoprotein levels and ultrasonography. RESULTS: Vertical transmission predominates (61.8%) in Moslem children and horizontal (44%) in those born in Russia. At entry, 73 of 173 (42%) HBsAg(+) genotype D children were hepatitis B e antigen (HBeAg)(+), ranging from 27% to 67% among ethnic groups; 55 of 173 (32%) had ALT > 2 × upper normal limit (UNL), ranging from 21% to 39%. Of 100 anti-HBe(+) children, 85 (85%) were inactive carriers. During the follow-up period, seroconversion to anti-HBe was observed in 40 of 73 (55%) children with an annual rate of 11%; 35 of 40 (87.5%) had biochemical remission, and 28 of 35 (80%) lost HBV-DNA. In the anti-HBe(+) group, 27 of 100 (27%) lost HBV-DNA and 9 of 100 (9%) lost HBsAg. The annual seroconversion rate for HBeAg was significantly lower: in children with vertical transmission compared with horizontal (7.7% vs 14.8%, respectively, P < 0.001) and in Muslim children compared with both Christian children and those born in Russia (8.6% vs 12%, respectively, P < 0.001). No differences were found among the ethnic groups after adjusting for the mode of infection. Two of 173 children had progression of liver disease. CONCLUSIONS: The differences in HBeAg(+) status and seroconversion rate among the ethnic groups are related to the time/mode of HBV infection. The majority of children who developed anti-HBe immunity had biochemical remission, and a substantial number of the inactive carriers lost viremia during the observation period of up to 12 y.