Hepatitis B e antigen and antibody: detection by radioimmunoassay in chimpanzees during experimental hepatitis B

Hepatitis B e antigen (HBeAg) and its antibody (anti-HBe) were evaluated using a sensitive radioimmunoassay (RIA) in weekly serum samples obtained from nine chimpanzees experimentally infected with hepatitis B virus (HBV). In two chimpanzees with HBV infection with detectable hepatitis B surface antigen (HBsAG) for less than five weeks, and in one chimpanzee with documented HBV infection with no detectable HBsAg, HBeAg was not detected; in all three, anti-HBe became detectable early in the infection. In six chimpanzees in which HGsAg was detected for 16 weeks or longer, HBeAg was detected early in the infection; in five, anti-HBe became detectable and HBeAg undetectable prior to the clearance of HBsAg. The sixth remained HGsAg-positive and HBeAg-positive for more than two years and never developed anti-HBe. These results confirmed the sensitivity of this RIA and its value in predicting the course of HBV infections.