Long-term Hepatitis B Surface Antigen Profile and Seroclearance after Severe Acute Flares of Chronic Hepatitis B

Hepatitis B surface antigen (HBsAg) seroclearance remains uncommon in chronic hepatitis B (CHB) infection. During acute flares of CHB (AFOCHB), alanine aminotransferase elevation reflects a mounting immune response toward viral clearance. We hypothesized that severe AFOCHB is associated with a greater quantitative HBsAg (qHBsAg) decline and HBsAg seroclearance rate. A total of 75 patients with severe AFOCHB with alanine aminotransferase 10× the upper limit of normal were matched to a control group by age and sex in a 1:2 ratio. qHBsAg levels were measured at the time of flare and annually (for both cases and controls) until the last follow-up. The median follow-up times for patients with severe AFOCHB and controls were 8.8 and 10.5 years, respectively. The cumulative rate of HBsAg seroclearance was higher in the severe AFOCHB group than in the control group (11.8% vs 5.0%, p=0.04) despite the former group having a trend of a higher baseline median qHBsAg (3,127 IU/mL vs 1,178 IU/mL, p=0.076). Compared with the control group, the severe AFOCHB group had a greater annual qHBsAg reduction (-242.4 IU/mL/yr vs -47.3 IU/mL/yr, p=0.002). Increasing age (p=0.049), lower baseline qHBsAg (p=0.002), and severe AFOCHB (p=0.014) were independently associated with HBsAg seroclearance. However, the cumulative rate of hepatocellular carcinoma was significantly higher in the severe AFOCHB group than in the control group (15.8% vs 1.9%, p