RESUMEN
PURPOSE: We investigated the spontaneous seroconversion rate of hepatitis B viral markers and predictive factors affecting seroconversion in children with chronic hepatitis B. METHODS: The study population included 214 children diagnosed as chronic hepatitis B, with positive HBsAg, HBeAg and HBVDNA over six months, and all patients had a family history of chronic Hepatitis B. They were followed between May 1982 and Febrary 2003 in the Department of Pediatrics, Yonsei University College of Medicine. Serum HBsAg, HBeAg, anti-HBs, HBVDNA, and AST/ALT were measured every six months. RESULTS: The mean age of patients was 7.4+/-4.5 years. The loss of HBeAg, HBVDNA and HBsAg were observed in 44(19.2%), 34(15.9%) and 3(1.4%) children respectively. The patients with serum ALT levels over three times normal and with HBVDNA less than 1,000 pg/dL showed significantly higher seroconversion rates of HBeAg and HBVDNA(P<0.001). By analyzing with the life table method, the cumulative seroconversion rate of HBeAg was 11% at 10 and 35% at 19 years of age, while HBVDNA was 9% at 10 and 32% at 19 years of age. In cases of HBsAg, the cumulative seroconversion rate was only 1.5% at 19 years of age. The age of patients, serum ALT and HBVDNA levels were proven as signifincant factors influencing the seroconversion of HBeAg and HBVDNA(P<0.001). CONCLUSION: In children with chronic hepatitis B, the seroconversion rate of HBeAg and HBVDNA are expected to be 35% and 32%, respectively, by the age of 19 years. The age of patients, serum ALT and HBVDNA levels seem to have significant influence on HBeAg and HBVDNA seroconversion.