Serum hepatitis B core-related antigen level stratifies risk of disease progression in chronic hepatitis B patients with intermediate viral load.

BACKGROUND: Patients with chronic hepatitis B virus (HBV) infection are at risk of developing liver disease. Serum hepatitis B core-related antigen (HBcrAg) is a new biomarker for intrahepatic templates for HBV replication. AIM: To explore whether a high HBcrAg level is associated with increased risk of cirrhosis, especially in patients with intermediate viral load (HBV DNA 2000-19 999 IU/mL) due to their moderate risk of disease progression. METHODS: A total of 1673 treatment-naïve, non-cirrhotic patients with negative hepatitis B e antigen (HBeAg) and alanine aminotransferase (ALT) level <40 U/L at baseline were enrolled. We explored the relationship between baseline levels of HBcrAg and cirrhosis development in all patients, and whether a higher HBcrAg level (<10 vs ≥10 KU/mL) was associated with an increased risk of disease progression in those with intermediate viral load. RESULTS: Of the 1673 patients, 104 developed cirrhosis after a mean follow-up of 15.9 years. Higher HBcrAg levels were associated with increased incidence of cirrhosis, cirrhosis-related complications, and liver-related death. In 445 patients with intermediate viral load, the cirrhosis risk stratified by HBcrAg level of 10 KU/mL yielded a hazard ratio of 3.22 (95% CI: 1.61-6.47). The risk stratification remained significant when exploring other pre-cirrhosis endpoints, including HBeAg-negative hepatitis, hepatitis flare, and HBV DNA >20 000 IU/mL after 3 years of follow-up. CONCLUSIONS: In HBeAg-negative patients with normal ALT levels, higher HBcrAg levels are associated with increased risk of cirrhosis. Among those with intermediate viral load, HBcrAg <10 KU/mL defines a low-risk group for disease progression.