Serum Level of Antibodies Against Hepatitis B Core Protein Is Associated With Clinical Relapse After Discontinuation of Nucleos(t)ide Analogue Therapy.

BACKGROUND & AIMS: Levels of antibodies against the hepatitis B virus (HBV) core protein (anti-HBc) have been associated with response to nucleos(t)ide analogue and (peg)interferon therapy in patients with chronic HBV infection. We performed a prospective study to determine whether the total serum level of anti-HBc level (immunoglobulins M and G) is associated with clinical relapse after discontinuation of nucleos(t)ide analogue-based therapy.

METHODS: We collected data from patients with chronic HBV infection who discontinued nucleos(t)ide analogue therapy according to pre-specified stopping criteria, recruited from November 2012 through July 2016 at an academic hospital in Guangzhou, China. Patients were followed through February 2017. We performed comprehensive biochemical and virologic tests at every visit, and anti-HBc was quantified for 2 years after treatment cessation (at baseline and weeks 4, 8, 12, 24, 48, and 96). The primary endpoint was clinical relapse, defined as level of HBV DNA >2000 IU/mL and level of alanine aminotransferase more than 2-fold the upper limit of normal-these were also the criteria for retreatment.

RESULTS: We followed 100 patients (71% positive for HB e antigen [HBeAg] at the start of nucleos(t)ide analogue therapy, 43% treated with entecavir or tenofovir) for a median of 2.5 years after stopping therapy. Clinical relapse occurred in 39 patients (in 46% of patients at year 4 after discontinuation). High level of anti-HBc at the end of treatment (hazard ratio [HR], 0.31 per log IU/mL; P = .002) and low level of HB surface antigen (HBsAg) at the end of treatment (HR, 1.71 per log IU/mL; P = .032) were associated with a reduced risk of clinical relapse after adjusting for age, start of nucleos(t)ide analogue therapy, HBeAg-status, and consolidation therapy duration. At year 4, 21% of patients with anti-HBc levels at the end of treatment ≥1000 IU/mL developed a clinical relapse compared to 85% of patients with levels <100 IU/mL (P < .001). An HBsAg level at the end of treatment ≤100 IU/mL was associated with a reduced risk of relapse (HR 0.30; P = .045). However, 82% of patients had levels of HBsAg above 100 IU/mL; for these patients, level of anti-HBc at the end of treatment could be used to determine the risk of relapse (HR 0.39 per log IU/mL; P = .005).

CONCLUSION: In a median 2.5-year follow-up study of patients with chronic HBV infection who stopped nucleos(t)ide analogue therapy, total serum level of anti-HBc at the end of treatment was associated with risk of clinical relapse. Serum level of anti-HBc might be used to select patients suitable for discontinuing nucleos(t)ide analogue therapy.