Impact of age at HBsAg seroclearance on hepatic outcomes and life expectancy in men with chronic HBV infection based on multi-state modeling of the natural history

Background: The effects of age at HBsAg seroclearance on clinical outcomes and survival in chronic hepatitis B (CHB) have not been adequately assessed. We evaluated the impact of age at HBsAg seroclearance on long-term outcomes, along with how coexisting factors modified risks and life expectancy in CHB patients. Methods: We used multi-state modeling approach to examine transitions through the CHB continuum in a longitudinal cohort study of male civil servants recruited in 1989–1992. Hepatic outcomes and deaths were identified by clinical evaluation and linkage with national health databases. Four sets of risk factors (CHB-related, metabolic, lifestyle, and genetic factors) were assessed. Results: Of 2551 HBsAg carriers, with follow-up until 2021 or death, 695 achieved HBsAg seroclearance, 490 developed cirrhosis (88 decompensated), 252 developed hepatocellular carcinoma (HCC), and 652 died. The cumulative rates for HCC were 1.1% and 1.5% at 10 years after HBsAg seroclearance, respectively, for patients achieving seroclearance at age 50 and 60; correspondingly, the rates for cirrhosis were 2.3% and 3.0%. Developing HBsAg seroclearance was associated with a reduced risk of cirrhosis (HR = 0.37, 95% CI 0.15–0.92) but not HCC. Patients experiencing HBsAg seroclearance lived longer years free of major liver diseases than HBsAg-persistent patients, and achieving seroclearance at age 50 (vs 60) led to a greater increase in the disease-free life expectancy. However, obesity and smoking were associated with adverse hepatic outcomes and loss of the disease-free life expectancy following HBsAg seroclearance. Conclusions: Our findings highlight the benefit of earlier HBsAg seroclearance for gains in disease-free life expectancy and the impact of obesity and smoking on loss of the life years free of major liver diseases following HBsAg seroclearance.