Sequential studies of pre‐S2 antigenemia and anti‐pre‐S2 antibodies in relation to viral replication in acute hepatitis B followed from the early incubation phase

To determine the time sequence of expression of pre‐S2 peptide (120–150) during the presymptomatic phase of acute hepatitis B, we used a monoclonal antibody radioimmunoassay in five subjects followed from 30 to 70 days before the onset of liver damage. Pre‐S2 peptide was present in serum at low levels from the early incubation phase and started to increase immediately after the first detection of HBV‐DNA in serum, in parallel with the increase in HBsAg levels. During the symptomatic phase, levels of pre‐S2 peptide declined rapidly; it was no longer detectable after recovery. Anti‐pre‐S2 antibodies were detected, in four patients, only in the recovery phase. These results demonstrate that expression of pre‐S2 peptide occurs very early in the incubation phase of acute HBV infection and is cleared in parallel with HBsAg. Anti‐pre‐S2 antibodies seem to play no role in viral clearance in these patients.