Role of HBsAg decline in patients with chronic hepatitis B HBeAg-negative and E genotype treated with pegylated-interferon

Treatment options for patients with chronic hepatitis B (CHB) and hepatitis B e antigen (HBeAg)-negative are pegylated interferon alfa-2a (PEG-IFN) for 48 weeks or nucleos(t)ide analogues (NAs). The choice of patients with higher chance of sustained response (SR) to PEG-IFN can be made with pre-treatment and on-treatment factors; recent studies evidenced the role of early drop of serum hepatitis B surface antigen (HBsAg) as predictor of SR. The aim of this study was the evaluation of early decrease of HBsAg on the SR in HBeAg-negative patients with E genotype. A retrospective analysis was performed on 72 patients affected by HBeAg-negative CHB with E genotype, treated for 48 weeks with PEG-IFN. HBsAg and HBV-DNA kinetics were evaluated. Decline of HBsAg (>0.5 logIU/mL) and HBV-DNA (≥2 logIU/mL) at 12 weeks was described according to observed chance of SR. After 96 weeks of follow-up, SR was observed in 10 patients (13.9%); HBsAg loss 6 (8.3%), HBsAg seroconversion in 3 (4.2%). No patients with HBsAg decline ≤0.5 log IU/mL and HBV-DNA<2 logIU/mL achieved SR (negative predictive value, NPV 100%). In multivariate analysis were significantly associated with SR the combined decline of HBsAg and HBV-DNA at 12 weeks (OR = 35.336; 95% CI: 4.668-112.226; p < 0.001) and the HBsAg≤7500 IU/mL at 24 weeks (OR = 51.824; 95% CI: 9.692-134.144; p < 0.001). Combining the HBsAg and HBV-DNA decline at 12 weeks we can identify patients without chance of SR who may stop PEG-IFN treatment. Stopping rule at 24 weeks using HBsAg≤7500 IU/mL is strong predictor of SR in HBeAg-negative patients with E genotype.