Hepatitis B Surface Antigen Levels During The Natural History Of Chronic Hepatitis B

Object: Serum quantity of HBsAg has been suggested as a predictor of treatment response in chronic hepatitis B. However, there is limited information on baseline HBsAg titres considering the dynamic natural course of HBV-infection.This study aimed to assess the change and clinical significance of the quantitation of HBsAg during the natural history of chronic hepatitis B.Method:99 HBV-monoinfected patients, not undergoing antiviral therapy, were analyzed in a cross-sectional study. Patients were categorized according to the phase of HBV-infection:immune tolerance phase (IT, n= 20), immune clearance phase(IC, n= 26), non/low-replicative phase (LR, n= 25), hepatits B e antigen negative hepatitis (ENH, n= 28). Serum HBsAg was quantified using chemiluminesent micropaticle immnoassay(CMIA), and HBV DNA load was measured using immunofluorescence quantitative polymerase chain reaction assay(PCR).Correlation of HBsAg titre with HBV DNA and serum ALT within each phase of infection was performed.Result:HBsAg titres were different between each phase of CHB (p<0.001):IT (4.92 Ig IU/ml), IC (4.07 lg IU/ml), LR (3.04 lg IU/ml), and ENH (3.54 lg IU/ml). HBsAg titres were highest in the IT phase, and lowest in the LR phase. In general, serum HBsAg was correlated with HBV-DNA levels (R= 0.65, p＜0.001). When analyzing different phases of persistent HBV-infection separately, serum HBsAg titres only correlated with HBV viral load in the IC phase. No correlation between the serum HBsAg level and ALT was observed.Conclusion:This study demonstrated significant differences in median baseline serum HBsAg titres across the different phases of CHB. Serum HBsAg was correlated with HBV-DNA levels in patients with persistent HBV-infection.These findings may have important implications for understanding the natural history of HBV-infection and for using quantitative HBsAg as a valuable clinical tool during antiviral therapies.