Seventy-six children aged 1-13 years who were known to be positive for hepatitis B surface antigen and hepatitis B e antigen in serum for at least 6 months and who had biopsy-proven chronic hepatitis have been followed longitudinally for 1-12 years (mean, 5 years). Twenty-three of them are now young adults. Eight patients had acute type B hepatitis 12-24 months before entering the study, while 68 patients came to observation during a chronic phase. At the beginning of follow-up, all 76 children were positive in serum for hepatitis B virus DNA, and 44 (58%) had chronic active hepatitis, associated with cirrhosis in two cases. During follow-up, 23 (30%) patients remained hepatitis B e antigen-positive, most with unchanged biochemical and hist...