[Clinical importance of hepatitis B virus DNA detection in serum of children with chronic hepatitis B]

206 sera from 172 children with chronic hepatitis B infection were tested for HBV DNA by dot blot hybridization. 111 were positive and 95 negative for HBV DNA. 103 (78.6%) of the positive patients had HBeAg and 5 (7.7%) anti-HBe. In 60 (92.3%) of the anti-HBe positive sera no HBV DNA could be detected. Children with elevated liver enzymes had HBV DNA in 80.1%, whereas in 71.6% of the chronic HBsAg carriers with normal liver enzymes no HBV DNA was found. In 87 of the 95 dot blot negative patients polymerase chain reaction was performed. 73 (83.9%) children of this group were HBV DNA positive. All HBeAg positive patients and those with elevated aminotransferases had HBV DNA in their serum. 56 anti-HBe-positive HBsAg carriers were also positive; 14 were negative for HBV DNA. Our results demonstrate that viral sequences can be found in all HBeAg positive and in most of the anti-HBe positive children. Patients with ongoing virus replication have to be considered infectious and recommendation for vaccination of close relatives of these patients must be stressed.