Quantitative analysis of pre-S1 and pre-S2 in relation to HBsAg expression

Sera from four patients with acute hepatitis B and 87 patients with chronic hepatitis B were examined quantitatively for pre-S1 and pre-S2 antigens by solid-phase enzyme immunoassays. Pre-S1 and pre-S2 antigens were detected in HBsAg-positive sera irrespective of the presence of viral replicative markers, and their titers correlated with those of HBsAg (r = 0.74, p less than 0.01; r = 0.74, p less than 0.01, respectively). Sera positive for HBeAg showed higher titers of pre-S1 (p less than 0.01) and pre-S2 (p less than 0.01) antigens than sera negative for HBeAg. The titers of pre-S1 and pre-S2 antigens also correlated with the levels of HBV-associated DNA polymerase activity (r = 0.51, p less than 0.01; r = 0.59, p less than 0.01, respectively) and HBV-DNA (r = 0.50, p less than 0.01; r = 0.46, p less than 0.01, respectively). However, the ratios between the titers of pre-S antigens and HBsAg had no significant relationships with those viral replicative markers. These findings suggest that the expression of pre-S antigens is intimately related to the expression of HBsAg and that they are not useful as markers of viral replication. The ratios between the titers of pre-S antigens and HBsAg tended to be high in patients with chronic active hepatitis and high aminotransferase levels. This finding may have been due to the hepatic release of pre-S antigens, over-production of which may have some relationship to liver injury.