[Distribution characteristics of serum HBsAg levels in Chinese patients with chronic hepatitis B based on CR-HepB].

Objective: To explore the distribution characteristics of HBsAg levels in treatment-naïve and treatment-experienced patients with chronic hepatitis B (CHB) in China. Methods: Data were obtained from the China Registry of Hepatitis B (CR-HepB) platform from the establishment of the platform to April 11, 2024. Patients with CHB who were treatment-naïve and treatment-experienced with nucleos(t)ide analogs (NAs) were included. Relevant clinical data were collected. The distribution of hepatitis B surface antigen (HBsAg) status, as well as the levels in populations of different age groups after different antiviral treatment durations, were retrospectively analyzed. Normally and non-normally distributed measured data were represented by Mean±SD, and M(Q1, Q3). Results: A total of 13 505 treatment-naïve patients and 6 390 treatment-experienced patients were included in the analysis. The proportions of treatment-naïve patients with HBsAg<100, <500, and <1 500 IU/mL were 10.51%, 28.47%, and 46.85%, and the corresponding proportions of treatment-experienced patients were 12.88%, 29.84%, and 52.07%. The proportions of treatment-naïve patients with HBsAg levels≥1 500, ≥3 000, and≥8 000 IU/mL were 53.15%, 38.17%, and 15.62%, and the corresponding proportions of treatment-experienced patients were 47.93%, 31.77%, and 10.39%. HBsAg level showed a trend of gradual decrease with the increase of antiviral treatment time. The proportion of treatment-experienced patients with HBsAg<100 IU/mL increased from 12.73% when the treatment duration was less than three years to 26.92% when the treatment duration was≥10 years, while the proportion of patients with HBsAg levels≥3 000 IU/mL or≥8 000 IU/mL decreased from 34.66% to 23.08% and from 12.19% to 5.77%, respectively. The proportion of patients with HBsAg<100, <500, and<1 500 IU/mL increased with age, while the proportion of patients with HBsAg≥1 500, ≥3 000, and ≥8 000 IU/mL decreased sequentially. Conclusions: The CR-HepB platform provides a basis for clarifying the serum HBsAg levels in treatment-naïve and treatment-experienced CHB patients in China. The HBsAg status indicates that with a prolonged antiviral treatment duration, there is a gradual decline trend in HBsAg level.