It has been shown that hepatitis B virus (HBV) X
antigen (HBxAg) functioned as a transactivating
element which can act on the enhancer of HBV in an in vitro system and elevate the transcriptional level of HBV. In this study we investigate the relationship between HBxAg expression and HBV replication in patients with
chronic hepatitis B and
cirrhosis. Rabbit
IgG against recombinant HBxAg which was synthesized in E. coli were prepared and used for the detection of HBxAg. HBV
DNA was amplified by polymerase chain reaction technique by using primers from HBx gene sequence. Liver tissue samples and sera from the patients were examined immunohistochemically for HBxAg and serologically for HBxAg/anti-HBx respectively. We focused on its expression in these samples in comparison with markers of HBV replication. It was found that in liver HBxAg was present in 72.7% of the patients with chronic active hapatitis (CAH) and 92.6% of those with
cirrhosis, while the positivity rate of
HBcAg in
cirrhosis patients was only 47.8%. In the sera of the patients with CAH, chronic persistant
hepatitis and
cirrhosis HBxAg was present in 44.4%, 66.6% and 33.3% respectively. It was similar to that observed with
HBeAg. Moreover in these HBxAg positive sera HBV
DNA can also be detected. It was shown that higher rate of positivity of HBxAg was found in patients with replicative
markers (serum HBeAg, serum HBV
DNA or liver tissue
HBcAg positive). Our results indicate that expression of HBxAg is closely correlated with HBV replication and HBxAg may be an important marker in chronic HBV
infection.