Effect of ethanol on antigenicity of hepatitis B virus envelope proteins

Hepatitis B e antigen-positive human serum was treated with 50-90% ethanol at room temperature for 1-60 min, then the antigenicity of S antigen (hepatitis B surface antigen, in a narrow sense) was determined by radioimmunoassay and the antigenicities of pre-S1 and pre-S2 antigens were measured by enzyme immunoassay. In addition, hepatitis B virus (HBV) DNA in the treated serum was detected by polymerase chain reaction. All antigenicities markedly decreased within 60 min at an ethanol concentration of 70-80%, and the decrease was faster in pre-S1 and pre-S2 antigens than in S antigen. Although HBV DNA remained in all ethanol-treated serum samples, no HBV DNA was detected after treatment with 1% sodium hypochlorite for 1 min. Based on the results, we speculate that one mechanism of loss of HBV infectivity by ethanol is the inhibition of virus binding to hepatocytes.