Viral Determinants of Hepatitis B Surface Antigen Seroclearance in Hepatitis B e Antigen-Negative Chronic Hepatitis B Patients

Background. We studied whether quantification of serum HBsAg and HBV DNA levels could predict spontaneous HBsAg clearance in patients with negative hepatitis B e antigen (HBeAg). Methods. Serum HBsAg and HBV DNA levels were measured at baseline among a longitudinal cohort of 103 HBeAg-negative patients recruited since 1997. Results. Twelve (12%) patients developed HBsAg seroclearance after 88 +/- 26 months (range, 21-139) of follow-up. At baseline, the serum HBsAg level among patients who cleared HBsAg (1.30 +/- 1.27 log IU/mL) was significantly lower than those who did not clear HBsAg (2.96 +/- 0.84 log IU/mL; P < .001). The area under receiver operating characteristics (ROC) curve for serum HBsAg to predict HBsAg seroclearance was 0.90 (95% confidence interval [CI], 0.83-0.97; P < .001). Nine (75%) of 12 patients who had HBsAg seroclearance versus 8 (9%) of 91 who remained HBsAg-positive had serum HBsAg <= 100 IU/mL at the baseline (P < .001). An HBsAg cutoff of <= 100 IU/mL had 75% sensitivity and 91% specificity to predict HBsAg seroclearance. Baseline serum HBV DNA could not predict HBsAg seroclearance; the area under ROC curve was 0.64 (95% CI, 0.46-0.81; P = .13). Conclusions. Single-point serum HBsAg level can predict the chance of HBsAg seroclearance in chronic hepatitis B patients with negative HBeAg.