The role of quantitative hepatitis B surface antigen (HBsAg) levels in patients receiving highly potent oral antiviral therapy is controversial, and here, we determined the HBsAg response in 121 chronic hepatitis B patients treated with tenofovir 300 mg daily. During tenofovir treatment, HBsAg decline of ≥ 1.0 log from baseline was seen in 16.1%, 16.3%, 18.4%, 34.6%, 36.4% and 11.8%, 15.2%, 14.8%, 28.6%, 20% at years 1, 2, 3, 4, 5 for HBeAg-positive and HBeAg-negative patients, respectively. Early decline in HBsAg levels at week 4 was predictive of subsequent significant HBsAg level decline. HBeAg seroconversion occurred in 29.9% of HBeAg-positive patients. On multinomial logistic regression, HBsAg level decline from baseline at week 4 and week 12 or any time subsequently did not correlate with HBeAg seroconversion and HBV DNA level decline from baseline at week 4 and week 12 (OR = 3.704; 95% CI = 1.511-9.076; P = 0.006 and OR = 1.732; 95% CI = 1.032-2.867; P = 0.037, respectively) was significantly predictive of seroconversion. A small proportion of chronic HBV-infected patients treated with tenofovir exhibit a significant (≥ 1.0 log) decline in HBsAg levels. Early decline in HBsAg levels at week 4 was predictive of subsequent and significant HBsAg level decline. The HBsAg decline did not correlate with HBeAg seroconversion in HBeAg-positive patients. Reduction in HBV DNA levels at week 4 and 12 correlated with seroconversion.
Keywords: HBV; HBeAg; HBsAg; chronic hepatitis; seroconversion; tenofovir.
© 2013 John Wiley & Sons Ltd.