X region deletion mutants associated with surface antigen-positive hepatitis B virus infections

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.

Viremia was assayed in virus-infected and control patients using the polymerase chain reaction and Southern blotting.

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.

Infection with X region mutants precedes that of wild-type virus, and they reappear after wild-type virus is eliminated in carriers.