Management of hepatitis B virus (HBV) reactivation in patients with resolved HBV infection based on a highly sensitive HB core-related antigen assay.

ABSTRACT

AIMS: To prevent hepatitis B virus (HBV) reactivation-related hepatitis, we examined the clinical usefulness of a highly sensitive HB core-related antigen (iTACT-HBcrAg) assay in patients with resolved HBV infection after nucleos(t)ide analog (NA) treatment for HBV reactivation. METHODS: We retrospectively analyzed 27 patients with resolved HBV infection who experienced HBV reactivation (defined as HBV DNA levels of 1.3 log IU/ml or more), and who received systemic chemotherapies for hematological malignancies between 2008 and 2020. iTACT-HBcrAg, HBsAg-HQ, and antibodies against hepatitis B surface antigen (anti-HBs) were measured using samples stored after HBV reactivation. The lower limit of quantification for iTACT-HBcrAg was 2.0 log U/ml. RESULTS: HBV reactivation was diagnosed at a median HBV DNA level of 1.8 log IU/ml, and then all patients received NA treatment. No patient had HBV-related hepatitis with a median maximum HBV DNA level of 2.0 log IU/ml. The positivities of iTACT-HBcrAg and HBsAg-HQ were 96% and 52% after HBV reactivation, respectively. Of 25 patients with detectable iTACT-HBcrAg at the initiation of NA treatment, 17 (68%) achieved iTACT-HBcrAg loss. Median durations from NA treatment to HBV DNA loss and iTACT-HBcrAg loss or the last follow-up were 35 and 175 days, respectively. Recurrence of HBV reactivation after NA cessation was not observed in seven of eight patients who achieved iTACT-HBcrAg loss or seropositive for anti-HBs during follow-up, except for one without anti-HBs after allogeneic transplantation. CONCLUSIONS: iTACT-HBcrAg could be a potential surrogate marker for diagnosing early-stage HBV reactivation as well as safe cessation of NA treatment in patients with resolved HBV infection after HBV reactivation.