HBsAg Seroclearance and Seroconversion: Incidence and Patient Profiles at the Centre Hospitalier Universitaire Yalgado Ouedraogo

Introduction: HBsAg seroclearance is a rare event in the natural history of chronic hepatitis B virus (HBV) infection. Data on HBsAg seroclearance and seroconversion are scarce in Burkina Faso. This study assessed the incidence and determined the profile of patients with HBsAg clearance and conversion at the Yalgado Ouédraogo University Hospital. Patients and Methods: This was a retrospective descriptive cross-sectional study conducted from 1 January 2006 to 31 July 2023, i.e. 17 years and 6 months, at the Yalgado Ouédraogo University Hospital. Patients were included who were chronic HBV carriers who had lost HBsAg spontaneously or after the introduction of nucleoside analogue therapy, had a viral load of HBV on admission and were negative for antibodies to hepatitis C virus (HCV), hepatitis D virus (HDV) and human immunodeficiency virus (HIV). HBsAg seroclearance was defined as serum HBsAg negativity, checked at least once, and seroconversion as the disappearance of serum HBsAg and the appearance of anti- Bs antibodies > 10 IU/ml. Results: Of the 1507 patients in our cohort, 27 lost their HBsAg during the study period. The overall incidence of HBsAg loss was 1.8% and 55.5% of patients seroconverted to HBsAg within 12 months of HBsAg loss. The mean age of patients on admission was 31.3 ± 8.9 years, with a sex ratio of 2. The mean age of patients at the time of HBsAg loss was 39.9 ± 10.2 years. The mean duration of HBsAg carriage was 9 ± 5 years. All patients were inactive carriers. Untreated patients represented 74.1% of the cohort. Quantitative HBsAg was less than 100 IU/mL in 81.8% of patients, and 88% of patients had undetectable DNA before loss of HBsAg. Conclusion: Although HBsAg seroclearance is associated with a good long-term prognosis, it remains a rare event. Patients at risk of developing hepatocellular carcinoma (HCC) after HBs seroclearance should be monitored at intervals that can be determined on the basis of further studies.