Evaluation of a new radioimmunoassay for detecting hepatitis B e antigen and its antibody

A new commercially available radioimmunoassay (RIA) (Abbott-HBeTM) was used for determination of hepatitis B e-antigen (HBeAg) and its antibody (anti-HBe). Serial serum samples from 20 transiently HBsAg-positive patients with acute hepatitis were tested. In nearly all patients HBeAg could be shown for a short period with subsequent development of anti-HBe. From 24 chronic HBsAg carriers serial serum samples collected during several years were tested. In 18 of 19 initially HBeAg-positive patients the HBeAg was lost after 6 months to 6 years; in 14 anti-HBe developed. A correlation was seen between the seroconversion and normalization of elevated alanine transferase levels. From another 22 chronic HBsAg carriers single serum samples were assayed. These samples were selected because neither HBeAg nor anti-HBe could be detected by the immunodiffusion (ID) technique. They had previously been examined for HBV-associated DNA-polymerase activity. In 20 patients HBeAg or anti-HBe could be detected by RIA. Those who were DNA-polymerase negative had anti-HBe, and 3 of 4 who were DNA-polymerase positive had HBeAg. When compared to earlier results by ID in these materials a higher frequency of HBeAg and, in particular, anti-HBe was detected by the RIA. By this test, HBeAg or anti-HBe was found in nearly all patients. The usefulness of HBeAg/anti-HBe in the evaluation of infectivity and prognosis in hepatitis B has been limited by the low sensitivity of the earlier test systems. Thus, this new RIA is a valuable addition to the diagnostic tests for patients with hepatitis B.