Serodiagnosis of acute hepatitis B virus infection by a modified competitive binding radioimmunoassay.

Using the Staphylococcus aureus absorption method, we have modified a commercial radioimmunoassay kit for the determination of total antibody to hepatitis B core antigen so that we can now determine the predominant globulin species of that antibody. One-hundred percent of acute hepatitis B sera had a predominance of immunoglobulin M antibody to hepatitis B core antigen, whereas immunoglobulin G antibody to hepatitis B core antigen was predominant in 98.2% of chronic hepatitis B surface antigen carriers. With this test and the commercially available tests for immunoglobulin M anti-hepatitis A virus, one can now reasonably differentiate acute hepatitis B from non A/non B hepatitis in a chronic hepatitis B surface antigen carrier.