Hepatitis B virus antigen quantitation by radioimmunoassay (RIA) in viral hepatitis and in chronic liver diseases.

The incidence of HBAg in viral hepatitis, in chronic active hepatitis and in cirrhosis has been investigated by using immunological methods and a solid-phase radioimmunoassay. RIA demonstrated as positive: 90% of 20 patients with posttransfusion hepatitis; 88% of 50 patients with acute viral hepatitis; 100% of 13 patients with chronic active hepatitis and 35% of 20 patients with cirrhosis; whereas the frequency of HBAg in the same patients appeared to be lower by AGD, CIEP and CF. The measure of antigenaemia has been obtained by use of HBAg (ad) dose response standard curve. The quantitative HBAg data of an eight-week follow-up of fully recovered 15 patients with acute hepatitis are reported. In the first week it appeared a distribution of the HBAg levels into three classes of values. The concentration of HBAg in the serum became lower week by week and in 8th week the antigen was no longer detectable. The radioimmunoquantitation of HBAg in the serum of patients suffering from chronic acitve hepatitis and cirrhosis showed wide levels of antigenaemia ranging between 17 and 5100 ng ad equivalent/ml. The use of a dose response standard curve in order to quantify HBAg in the serum represents a further increased sensitivity of RIA.