X-REGION DELETION MUTANTS ASSOCIATED WITH SURFACE ANTIGEN-POSITIVE HEPATITIS-B VIRUS-INFECTIONS

Background/Aims: The finding of antibodies against the polymerase of hepatitis B virus in renal dialysis patients before the incubation phase of infection implies underlying virus replication. Hence, the aim of the study was to test for virus during infection. Methods: Viremia was assayed in virus-infected and control patients using the polymerase chain reaction and Southern blotting. Results: Six months before the appearance of surface antigen, most patients had detectable core region, but few patients were X region positive. Three months after surface antigen appeared, most carriers had detectable core and X products. Three years after surface antigen appeared, 5 of 8 carriers with persistent hepatitis B e antigen and 1 of 8 carriers with corresponding antibody had these products. Cloning and sequencing showed deletions within the X/precore region of viral DNA. Conclusions: Infection with X region mutants precedes that of wild-type virus, and they reappear after wild-type virus is eliminated in carriers.