Risk factors for relapse after discontinuation of tenofovir or entecavir in hepatitis B e antigen-negative patients

Background and Aim: This study aimed to define the relapse frequency and risk determinants in chronic hepatitis B (CHB) patients who discontinued nucleoside analog (NA) treatment, were HBeAg-negative, and had achieved both a virological and biochemical response. Materials and Methods: This retrospective cohort study reviewed patients with HBeAg-negative CHB who received antiviral therapy for at least 65 months between January 1, 2013, and December 31, 2020. These patients discontinued treatment after demonstrating a biochemical and virological response and were evaluated at 6, 12, and 24 months post-treatment discontinuation. Results: Sixty-seven patients with CHB who received NA therapy for at least 65 months, discontinued treatment, and had undetectable HBV DNA and normal ALT values were evaluated. After cessation of NA therapy, a relapse was observed in 38 patients (56.7%). The relapse rate was 71.0% in patients treated with tenofovir disoproxil fumarate (TDF) as the last NA type and 37.9% in patients treated with entecavir (ETV) (p=0.017). The cutoff value for the best estimate of age for predicting relapse was 42 years. The relapse rate was 69.2% in patients aged >42 years and 39.2% in patients aged <42 years (p=0.007). The relapse rate was 51.3% in patients with a pre-treatment fibrosis score of 2, 56.0% in those with a fibrosis score of 3, and 100% in those with a fibrosis score of 4 (p=0.089). Conclusion: Among HBeAg-negative CHB patients who achieved a virological and biochemical response to long-term antiviral therapy, those aged 42 years and older, those with high fibrosis scores before treatment, treatment.