Characterisation of people living with chronic hepatitis B virus infection in England and stratification by HBsAg levels: A cross-sectional study.

Characterisation of people with hepatitis B (PwHB) remains limited, particularly regarding treatment status, disease severity and biomarker profiles. Quantitative hepatitis B surface antigen (qHBsAg) is a key predictor of response to emerging therapies, but its distribution is poorly described. Using a large, ethnically diverse UK cohort, we assessed demographics, clinical features and HBsAg levels to guide treatment strategies. This cross-sectional analysis of PwHB (N = 2000 [prespecified]) used data from four English hospitals, collected via the National Institute for Health and Care Research Health Informatics Collaborative framework. Individual characteristics were assessed overall, and post hoc by qHBsAg levels (≤ 3000/> 3000 IU/mL; < 100/≥ 100-≤ 1000/> 1000 IU/mL) available from one centre (N = 457). The cohort had a slight male predominance (54%) and a mean age of 44.9 years. White and Asian ethnicity each accounted for 25%, and 23% were on nucleos(t)ide analogue therapy. Centres collecting HBsAg data had more individuals with undetectable HBV DNA or on treatment. Among individuals with non-missing qHBsAg data (263/457), 167/263 (63.5%) had qHBsAg ≤ 3000 IU/mL. These were older (49.6 vs. 43.5 years), more likely to be male (53.9% vs. 35.4%), Asian (40.7% vs. 20.8%) or have undetectable HBV DNA (35.9% vs. 17.7%), and less likely to be Black (13.2% vs. 34.4%) versus those with qHBsAg > 3000 IU/mL. Fifty-six (21.3%) people had qHBsAg < 100 IU/mL, 60 (22.8%) between ≥ 100 and ≤ 1000 IU/mL, and 147 (55.9%) > 1000 IU/mL. This cohort of PwHB highlights qHBsAg distribution in clinical settings and could identify people more likely to achieve functional cure with emerging therapies.