Current data of hepatitis B virus (HBV) variants associated with treatment outcome identified by next generation sequencing (NGS) are limited. This study was aimed at determining the role of baseline sequence variations in the enhancer II (EnhII), basal core promotor (BCP) and pre-core (PC) regions of HBV genotype C in patients treated with pegylated interferon (PEG-IFN). Patients with HBeAg-positive chronic hepatitis B (CHB) treated with 48-week PEG-IFN were enrolled. Combined response (CR) at week 96 was defined by HBeAg seroconversion plus HBV DNA < 2000 IU/mL and HBsAg < 1000 IU/mL. Pre-treatment viral mutations were characterized by Sanger sequencing and NGS (Miseq Illumina platform). Among 47 patients (32 male, mean age 32.4 years), CR was achieved in 12 (25.5%) individuals. Overall, NGS was superior to Sanger sequencing in detecting mutations (61.7% vs. 38.3%, P < 0.001). Based on NGS, the prevalence of T1753V (T1753C/A/G) and A1762T/G1764A variants were significantly lower in responders compared to non-responders (8.3% vs. 51.4%, P = 0.009 and 33.3% vs. 68.6%, P = 0.032, respectively). No significant difference between groups was found regarding C1653T and G1896A mutants. The absence of T1753V and A1762T/G1764A mutations were factors associated with CR (OR 11.65, 95%CI 1.36-100.16, P = 0.025, and OR 4.36, 95%CI 1.08-17.63, P = 0.039, respectively). The existence of pre-treatment T1753V, A1762T/G1764A mutations and their combination yielded negative predictive values of 94.7%, 85.7% and 93.8%, respectively. The presence of HBV mutants in the BCP region determined by NGS at baseline was associated with poor treatment outcome in patients with HBeAg-positive CHB receiving PEG-IFN.
Keywords: HBV; Mutations; NGS; PEG-IFN; Treatment response.