Characteristics of hepatitis B core antibody level in the natural history of chronic hepatitis B.

Objective. We aimed to analyze serum antibody to hepatitis B core antigen (anti-HBc) level during different immunological phases in the natural history of patients with chronic hepatitis B (CHB). Methods. Serum anti-HBc levels in the immune tolerant (IT), immune clearance (IC), low replicative (LR), and HBeAg negative hepatitis (ENH) phases from 634 treatment-naive CHB patients were measured and compared between phases and with other serum markers. Results. Median serum anti-HBc levels were different between the phases of CHB. Serum anti-HBc level was highest in the ENH phase and lowest in the IT phase. Serum anti-HBc level correlated only with ALT in the IC phase (r = 0.248, p < 0.001). The area under the receiver operating characteristic curve (AUC) of anti-HBc at a cutoff value of 9.03 S/CO for differentiation of IT and IC phases was 0.689 (sensitivity 74.03%, specificity 60.23%). The AUC for differentiation of LR and ENH phases was 0.751 (sensitivity 68.32%, specificity 70.53%) at a cutoff value of 9.74 S/CO for anti-HBc. Conclusions. Serum anti-HBc levels were significantly different across different phases of CHB and were associated with hepatitis activities.