Presence of HBeAg in the serum indicates active replication of virus and is usually associated with HBV DNA. HBeAg to HBeAb seroconversion occurs early in patients with acute infection, prior to HBsAg-to-HBsAb seroconversion. However, HBeAg seroconversion may be delayed for years to decades in chronic infection. HBeAg-to-HBeAb seroconversion usually associated with disappearance of HBV DNA in serum. Presence of HBeAb in the serum usually indicates that the virus is no longer replicating. Limited use clinically.
Normal range: Negative.
Use
Diagnosis and monitoring of HBV infectivity. Recognition of resolution of hepatitis B infection with seroconversion of HBeAg to HBeAb.
Interpretation
Presence indicates highly infective stage of hepatitis B.
Limitations
Persistence of HBeAg is associated with chronic liver disease.
Presence of HBeAg implies infective HBV present in the serum, but its absence on conversion to HBeAb does not rule out infectivity, especially in persons infected with genotypes other than A.
During the HBeAg-positive state, usually 3 " �6 weeks, hepatitis B patients are at increased risk of transmitting the virus to their contacts, including babies born during this period. Exposure to serum or body fluid positive for HBeAg and HBsAg is associated with three to five times greater risk of infectivity than when HBsAg positivity occurs alone.
HBeAg may be negative in the "precore mutant " � form of hepatitis B and can be highly infectious. HBeAg-negative strains respond similarly to antiviral treatment.
Measurement of HBV DNA is now recommended, especially in persons with increased ALT but negative HBeAg.