Objective: To quantitatively detect intrahepatic HBV covalently closed circular DNA (cccDNA) and serum HBsAg; and to analyze the relationship between the two parameters and with serum HBV DNA level.
Methods: Intrahepatic cccDNA (copies/cell) was quantitated by plasmid-safe ATP-dependent Danes (PSAD) digestion in combination with rolling circle amplification and gap-spanning selective real-time PCR assay using formalin fixed paraffin-embedded liver biopsy samples. HBsAg was measured by chemiluminescence's reagent manufactured by Abbott Company using sera sampled at time-point of liver biopsy.
Results: Intrahepatic cccDNA level was positively correlated with serum HBsAg level (r = 0.459, P < 0.001), but not correlated with serum HBV DNA level. Serum HBsAg level was positively correlated with serum HBV DNA level (r = 0.328, P = 0.015), and reversely correlated with HBV replicative efficiency defined as the ratio of serum HBV DNA to cccDNA (r = -0.373, P = 0.005).
Conclusion: In patients with chronic hepatitis B, intrahepatic cccDNA level is correlated with serum HBsAg level. The two parameters combined with serum HBV DNA may comprehensively reflect HBV replication activity and help evaluation of antiviral therapeutic efficacy.