Hepatitis B antigen: distribution of ad and ay subtypes in blood donors and hepatitis patients.

Hepatitis B antigen (HBAg) from blood donors and patients with hepatitis was tested for ad and ay subspecificity by immunodiffusion in agarose. A total of 59 sera from blood donors and 81 sera from hepatitis patients were subtyped.Subtyping of HBAg from blood donors showed ad and ay subspecificity in 64.4 and 35.6% of cases respectively. Patients' sera on the other hand showed HBAg with ad and ay subspecificity in 6 and 94% of cases respectively. Therefore, ad subtype was more frequently associated with blood donors whereas ay subtype was predominant among hepatitis patients. The relationship between clinical findings and HBAg subtype is also discussed.