Prediction of disease reactivation in asymptomatic hepatitis B e antigen-negative chronic hepatitis B patients using baseline serum measurements of HBsAg and HBV-DNA.

Differentiating 'inactive carriers' (ICs) of hepatitis B virus (HBV) from hepatitis B e antigen-negative (HBeAg[-]) patients in remission is challenging. We investigated whether serum-based monitoring of hepatitis B surface antigen (HBsAg) and HBV-DNA in asymptomatic HBeAg(-) patients could distinguish these groups.

Methods: 129 HBeAg(-) chronic hepatitis B (CHB) patients (HBV genotypes A-E) with normal alanine aminotransferase (ALT) levels at baseline were classified after 1 year of follow-up as either IC (HBV-DNA ≤2000 IU/mL) or 'active carrier' (AC, HBV-DNA >2000 IU/mL) if they exhibited normal ALT throughout, or classified as 'reactivation patient' (RP) if they exhibited marked, transient increases in ALT and HBV-DNA.

Results: There were 64%, 18%, and 19% patients in the IC, AC, and RP groups, respectively. Combined HBsAg and HBV-DNA cutoffs (>1000 IU/mL and >200 IU/mL, respectively) differentiated RPs with 92% sensitivity and negative predictive value (NPV) of 96%. HBsAg sero-clearance was associated with baseline HBsAg <1000 IU/mL, annual decrease of ≥0.3 log IU/mL (NPV 95%: PPV 89%) and IFNL3 genotype CC.

Conclusions: Applying combined HBsAg and HBV-DNA cutoffs to baseline measurements accurately differentiated RPs. These results suggest that HBsAg should be included in the monitoring of asymptomatic HBeAg(-) CHB patients.