OBJECTIVETo investigate the relationship between the expression of hepatitis B virus (HBV) core antigen and viral replication and liver tissue inflammation damage in chronic hepatitis B (CHB) patients, and to analyze the relationship of core antigen expression differences with clinical and pathological features in e antigen-negative and e antigen-positive CHB patients.

METHODSSixty-three treatment-naive patients diagnosed with CHB who underwent liver biopsy were included in this retrospective analysis. Liver pathology was assessed, and the karyotype, pulp type, and pulp karyotype were determined. Core and e antigen expression was quantitatively determined by automated immunoassay. Blood samples were used to determine the amount of peripheral lymphocytes or monocytes and HBV DNA load. Results The median titer of HBV DNA was significantly higher in the CHB patients with e antigen positivity (n = 48) than those with e antigen negativity (n = 15) (5.4 * 106 copies/ml vs. 5.4 * 104 copies/ml, P = 0.003). The core antigen positive expression rate was significantly higher in the e antigen-positive CHB patients than in the e antigen-negative CHB patients (80.33% vs. 53.33%, P = 0.042). For the e antigen-positive CHB patients, the HBV DNA titer in karyotype core antigen cases was higher than that in the pulp karyotype mixed-type cases (P = 0.008) and in the negative cases (P = 0.013); in addition, the karyotype patients showed higher titer than the plasma patients (P = 0.019). Also for the e antigen-positive CHB patients, the HBV DNA titer was positively correlated with the rank level of pulp karyotype in core antigen expression (r = 0.589, P = 0.003) but negatively correlated with lobular inflammation, interface inflammation, and fibrosis level (r = -0.552, P = 0.000; r = -0.381, P = 0.008; r = -0.555, P = 0.000); in addition, the level of peripheral blood lymphocytes was negatively correlated with lobular inflammation and fibrosis level (r = -0.361, P = 0.012; r = -0.356, P = 0.013). For the e antigen-negative CHB patients, the level of peripheral blood lymphocytes was negatively correlated with lobular inflammation and interface inflammation (r = -0.702, P = 0.004; r = -0.578, P = 0.024), while the level of peripheral blood mononuclear cells was negatively correlated with lobular inflammation, interface inflammation, and fibrosis level (r = -0.682, P = 0.005; r = -0.620, P = 0.014; r = -0.527, P = 0.044); in addition, age positively correlated with interface inflammation (r = 0.690, P = 0.004).

CONCLUSIONThe pulp karyotype mixed-type of core antigen expression may reflect the level of HBV replication. Negative expression of core antigen may be associated with variation in pre-C or C zone. The monocyte-macrophage system may be involved in the pathogenesis of e antigen-negative CHB, while the mechanism of immune escape may play an important role in increasing HBV DNA titer in an e-antigen-negative CHB condition.