The type of hepatitis B virus ("wild-type" or precore mutant) in anti-e antigen antibody-positive carriers, viral DNA levels in the serum, and core and e antigen expression in the liver were investigated to search for a possible correlation of these factors with the severity of liver damage. Two major groups of patients were found: the patients in group A were predominantly infected with precore mutant virus and had chronic active hepatitis, expressed nuclear/cytoplasmic core and e antigens in liver biopsy specimens, and usually had high levels of viral DNA in their serum; patients in group B were infected with a mixture of wild-type and mutant viruses, had predominantly chronic persistent hepatitis, showed weaker expression of nuclear core antigen with no cytoplasmic core or e antigen, and had low viremia. A few patients were infected with viruses without precore stop-codon mutation. These data indicate a high prevalence of precore mutant viruses in anti-e carriers with chronic liver disease and suggest that monitoring of virus sequence type and DNA level may be of prognostic value for liver disease sequelae.