| [ Summary ] |
Hepatocyte HBV cccDNA is the key molecule from which HBV replication starts, and thus, the amount of HBV cccDNA reflects HBV replication activity. The serum level of HB core‒related antigen (HBcrAg) has been reported as a marker reflecting cccDNA levels in hepato-cytes even under nucleo (ts) ide analogue (NUC) treatment. The HBcrAg assay measures all antigens coded by the pre‒core/core genome simultaneously, which includes HBcAg, HBeAg, and p22crAg, and has been reported to be useful for predicting clinical outcomes in patients who are treated with NUCs. The combined measurements of HBsAg and HBcrAg levels can predict reactivation of the HBV after discontinuing NUC administration, which is now included in the Japanese guidelines pertaining to NUC discontinuation. The combined measurements of HBsAg and HBcrAg levels are also reported for predicting outcomes of NUC/IFN sequential therapy. It is noteworthy that HBcrAg levels have been reported to be useful for predicting the risk of developing HCC in patients undergoing NUC therapy. |