Abstract: Objective To investigate the value of HBV RNA for predicting the therapeutic effect of long- term entecavir (ETV) antiviral therapy in patients with chronic hepatitis B (CHB). Methods Serum samples were collected from 59 CHB patients treated with ETV for 96 or 108 months. HBV RNA levels, HBV DNA levels, and serological marker (HBeAg) levels were measured at baseline and 3, 6, 9, 12, 36, 72, and 96 (or 108) months during the therapy. Results Although HBV RNA level decreased after 12 and 36 months of ETV antiviral therapy, no significance changes occurred in HBV RNA negative conversion rate (P>0.05). After 72 months of treatment or longer, 33 patients had HBV RNA levels lower than 100 copies/mL, and among them 29 patients had HBV RNA levels lower than the detection limit, and HBV RNA negative conversion rate was statistically significant (P<0.05). A lower HBV RNA level was associated with a higher HBeAg negative conversion rate (P<0.05). Age and HBV RNA level were positively correlated with HBeAg negative conversion rate (P<0.05). Conclusion Prolonged ETV antiviral therapy results in better clearance of HBV RNA and a higher negative conversion rate in CHB patients. The length of antiviral therapy and age are positively correlated with the negative conversion rate of HBV RNA, and earlier administration of the antiviral treatment achieves better therapeutic effect. Serum HBV RNA level can be used as an indicator for predicting conversion to negative HBeAg in CHB patients receiving ETV therapy

Key words: HBV RNA; efficacy; predictive value; entecavir