Hepatitis B core‐related antigen to detect hepatitis B virus (HBV) reactivation in heart transplant recipients with past HBV infection: A pilot study

Hepatitis B core‐related antigen (HBcrAg) has been proposed as a new marker of hepatitis B virus (HBV) replication. We analyzed HBcrAg dynamics in 15 heart transplant recipients with active or prior HBV infection and correlated it with quantitative (QT)‐HBsAg and HBV‐DNA pre‐ and post‐transplant. Serum HBcrAg was detected in HBsAg/HBV‐DNA‐positive subjects but not in recipients with past HBV infection. HBcrAg levels correlated with QT‐HBsAg in pre‐ and post‐transplant samples. In prior HBV infection, HBcrAg levels were unrelated to HBV‐DNA positivity. In heart transplant recipients with prior HBV infection, HBcrAg does not correlate with viral replication and cannot be applied to detect HBV reactivation during follow‐up.