Characterization of a new antigen-antibody system associated with hepatitis B.

The occurrence of a new antigen-antibody system was recently described in hepatitis B surface antigen (HBsAg) positive sera with different specificities, one of which was designated e. These specificities are related as demonstrated by the presently utilized e reagents not discriminating between them in immunodiffusion tests. Hence, they are collectively referred to as e in this report. The occurrence of e antibodies in sera containing antibodies against hepatitis B surface antigen (anti-HBs) is reported. The e antibodies were found to move as 7S globulin on rate zonal centrifugation. The e precipitate was demonstrated on the cathode side of the HBsAg precipitate on immunoelectrophoresis consistent with e antigen migrating in the gamma-globulin region. The e antigen is reported to have an S value of 11-6 +/- 0-6 (s.d.) and a buoyant density of 1-291 +/- 0-003 (s.d.), hence differing from HBsAg in all respects studied thus far.