Loss of HBsAg in Patients with High Levels of HBV-DNA During Treatment with Nucleoside or Nucleotide Analogs

Background: HBsAg is synthesized in the endoplasmic reticulum and is necessary for the formation of complete HBV particles. A decreased synthesis of this antigen leads to an intracellular inhibition of virus production. Methods: The study aimed to assess the incidence of HBsAg elimination among 1,290 patients who suffered from chronic HBV infection undergoing an antiviral treatment with nucleoside or nucleotide analogs (NAs). Furthermore, possible predictive factors for this elimination were analyzed. Results: A permanent HBsAg loss was confirmed in 3% of the patients, which was more frequent in men than in women (4.4% vs. 1.9%; P = 0.009). The HBsAg elimination occurred in 5% of HBeAg (+) patients and 2.8% of HBeAg (-) patients. The age of patients whose HBsAg was eliminated was higher than the age of the remaining patients (60 vs. 51 y/o). The effect of initially used pegylated interferon alfa (PEG-IFN) therapy on the HBsAg elimination was not observed. It occurred with the use of entecavir (ETV) and tenofovir (TDF); however, among patients treated with ETV, HBsAg was significantly more often eliminated in HBeAg (+) patients. Conclusions: The HBsAg elimination in patients undergoing antiviral treatment occurs more often in men, patients with positive HBeAg before treatment, individuals above 60 years, and patients treated with ETV.