Subtyping of Hepatitis-Associated Antigen (HB Ag); Simplified Technique with Counterelectrophoresis

Abstract

A simple and sensitive counterelectrophoresis technique for determining the subtype of hepatitis-associated antigen (HB Ag) in sera is described. Using monovalent antisera, or polyvalent antisera rendered monovalent by appropriate absorption, we detected a group-specific antigenic determinant, a, and two additional specificities, d and y. All HB Ag-containing sera could be subtyped as either ad or ay. The subtype appears to be determined by the viral agent, not the host, and to remain the same in affected individuals. While the frequency of subtypes ad and ay were about the same for patients with acute hepatitis, ad was much more common in patients with chronic hepatitis. Subtype ad was also detected more frequently than ay in blood donor carriers of HB Ag. The major values of subtyping for HB Ag will probably be in the study of the epidemiology of hepatitis B and the development of optimal testing reagents for HB Ag detection.