Rapid Decline Rather Than Absolute Level of HBsAg Predicts Its Seroclearance in Untreated Chronic Hepatitis B Patients From Taiwanese Communities.

INTRODUCTION

Hepatitis B surface antigen (HBsAg) clearance leads to favorable outcomes in patients with chronic hepatitis B. HBsAg levels <200 IU/mL with HBsAg decline >0.5 log 10 IU/mL in 1 year have been reportedly predictive of HBsAg loss. This study aimed to use the REVEAL-hepatitis B virus cohort to validate and simplify this prediction rule and verify whether the simplified algorithm can be used among various clinical subgroups.

METHOD

We analyzed 707 patients with untreated chronic hepatitis B who had 3 or more HBsAg measurements within 5 years before HBsAg seroclearance or last visit, greater than 1 year apart from one another. Rapid HBsAg decline was defined as HBsAg decline >0.5 log 10 IU/mL in 1 year or >1 log 10 IU/mL in 2 years. Sensitivity, specificity, positive predictive values, and negative predictive values were compared to assess the predictability of HBsAg seroclearance.

RESULTS

During a median follow-up of 10.7 years, 41 of the 707 patients cleared serum HBsAg. HBsAg levels at all measurements were lower ( P < 0.0001) and HBsAg decline was greater ( P < 0.0001) in patients with seroclearance compared with non-seroclearance patients. The predictive accuracy of predicting 1-year HBsAg loss using only the rapid decline algorithm (sensitivity = 0.4412, specificity = 0.9792, positive predictive value = 0.5172, negative predictive value = 0.972) was the same as the model combining rapid HBsAg decline and HBsAg levels <200 IU/mL. The simplified algorithm including only the rapid decline performed similarly among various levels of HBsAg, hepatitis B virus DNA, and alanine aminotransferase and was independent of inactive carrier state.

DISCUSSION

HBsAg decline >0.5 log 10 IU/mL/yr was a practical predictor of HBsAg seroclearance within 1 year in our community-based untreated cohort.