Simultaneous occurrence in the same serum of hepatitis B surface antigen and antibody to hepatitis B surface antigen of different subtypes.

The simultaneous occurrence of hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs) of different subtypes in the serum of a hemodiaylzed patient was studied. The w(a) subdeterminants were involved. The HBsAg belonged to the ayw3 subtype, and the anti-HBs exhibited monospecific anti-w2 activity. Both the HBsAg and the anti-HBs were detectable by counterelectrophoresis (CEP). The specificity of the antibody was demonstrated by CEP in tests against 128 sera containing HBsAg of 12 different subtypes and in absorption experiments with eight sera containing HBsAg of eight different subtypes, as well as by radioimmunoassay in the liquid phase. The monospecific antibody was selectively directed against the w2 subdeterminant of the adw2 subtype and was designated anti-w2.