Levels between pre-and post-treatment levels of natural antibody, complement C3, and inflammatory cytokines in the HBeAg-positive patients were not much changed, suggesting that host immune regulation by natural antibody and complement may be a steady-stage process during chronic hepatitis B. In contrast, natural antibody IgG1-3 and C3 levels were lower in the HBeAg-negative patients but virological response rate at 1 year after ETV treatment was higher in these patients (Table 2). Here, C3 is linked to chronic hepatitis B virus infection.