Objective The clinical significance of differential distribution of hepatitis B virus (HBV) nucleocapsid antigen in hepatocytes remains unknown. The goal of this study is to determine the relationship between distinct HBV core antigen distribution pattern and alanine transaminase (ALT), liver histological inflammatory activity grades, serum HBeAg status and HBV DNA level.
Methods Total of 958 cases with chronic hepatitis B were recruited into this study. Liver function tests, serum HBV DNA level, serological HBV markers and liver immunohistochemistry were examined according to the conventional instructions. Chi Square tests were performed to analyze the differences among these groups.
Results It was found that 552 (58%) cases were tested positive for HBV core antigen by immunohistochemical staining. Cytoplasmic hepatitis B core antigen (HBcAg) expression correlated with ALT level and serum HBV DNA and liver inflammatory activity scores, however, nuclear HBcAg expression in hepatocytes was associated with normal ALT level, lower liver inflammatory activity score and higher serum HBV DNA level and rate of HBeAg positivity. Both nuclear and cytoplasmic HBcAg expression in hepatocytes associated with a middle ALT level and liver inflammatory activity score, higher rate of serum detectable HBeAg and a higher HBV DNA level. However, undetectable core antigen was related to a lower ALT level and histological inflammatory activity grade, lower positive HBeAg rate and HBV DNA level.
Conclusions Undetectable liver HBcAg is associated with HBV clearance, ALT normalization and hepatitis B e antigen (HBeAg) seroconversion, and cytoplasmic HBcAg expression associated with higher hepatic inflammatory activity. However, nuclear HBcAg expression correlates with immune tolerance characterized with normal ALT and lower liver inflammatory activity, higher HBV replication level and higher rate of HBeAg positivity.