[Radioimmunoquantization of the HBAg in clinical liver diseases].

The two-step direct radioimmune test RIA used to detect hepatitis B virus associated antigen (HBsAg) appeared to be more sensitive than other immunologic assays. RIA demonstrated as HBsAg 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; on the other hand with positivity for HBsAg in the same patients appeared to be lower by AGD, CIEP and CF. The quantitation of HBsAg by RIA has been performed with a dose response curve obtained by use of HBsAg (ad) standard. The quantitative HBsAg data of an eight week follow-up of fully recovered 15 patients with acute B-hepatitis are reported. In the first week it appeared a distribution of the HBsAg levels into three classes of values. The concentration of HBsAg in the serum became lower week by week and in the 8th week the HBsAg was no longer detectable. The radioimmunoquantitation of HBsAg in the serum of patients suffering from chronic active hepatitis and cirrhosis showed levels of antigenaemia ranging between 17 and 5100 ng ad equivalent/ml. The use of a dose response standard curve in order to quantify HBsAg in the serum represents a further increased sensitivity of RIA.