title: Changes of HBsAg and HBV DNA levels in Chinese chronic hepatitis B patients after 5 years of entecavir treatment.
abstract: OBJECTIVE
  Hepatitis B surface antigen (HBsAg) kinetics during long-term entecavir therapy has not been well investigated.
  
  
  METHODS
  We described the cumulative serologic, virologic, and biochemical outcomes and the occurrence of signature entecavir mutations among 222 Chinese treatment-naïve chronic hepatitis B (CHB) patients receiving entecavir for up to 5 years.
  
  
  RESULTS
  The median rate of HBsAg reduction over 5 years was 0.125 log IU/mL/year. Patients with high baseline HBV DNA levels (≥ 8 log copies/mL or ≥ 7.3 log IU/mL), when compared with those with baseline hepatitis B virus (HBV) DNA < 7.3 log IU/mL, had a significantly greater median rate of HBsAg reduction (0.178 and 0.102 log IU/mL/year, respectively, P < 0.001). The difference in HBsAg decline was most prominent in the first year (0.324 and 0.062 log IU/mL/year, respectively, P < 0.001). Greater median rates of HBsAg reduction were also found in hepatitis B e antigen (HBeAg)-positive patients when compared with HBeAg-negative patients (0.144 and 0.098 log IU/mL/year, P = 0.015), and in patients with high baseline HBsAg levels (≥ 3 log IU/mL), when compared with patients with low baseline HBsAg < 3 log IU/mL (0.131 and 0.045 log IU/mL/year, respectively, P = 0.001). The 5-year cumulative rate of HBV DNA undetectability (< 20 IU/mL) was 97.1%. There were two cases of entecavir resistance, resulting in a 5-year cumulative resistance rate of 1.2%.
  
  
  CONCLUSIONS
  In contrast to the profound HBV DNA suppression, long-term entecavir treatment achieved only a slow decline in serum HBsAg. Although certain patient subgroups exhibit a more rapid HBsAg reduction, additional therapeutic agents are needed to increase the chance of HBsAg seroclearance in CHB.
authors: Department of Medicine, the University of Hong Kong, Queen Mary Hospital, Hong Kong.
authors: Wai-Kay
authors: WK
authors: Seto
authors: Yuk-Fai
authors: YF
authors: Lam
authors: James
authors: J
authors: Fung
authors: Danny Ka-Ho
authors: DK
authors: Wong
authors: Fung-Yu
authors: FY
authors: Huang
authors: Ivan Fan-Ngai
authors: IF
authors: Hung
authors: Ching-Lung
authors: CL
authors: Lai
authors: Man-Fung
authors: MF
authors: Yuen
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D006147:Guanine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000187:drug effects / Q000235:genetics* / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D013997:Time Factors; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; C413685:entecavir; D006147:Guanine
keywords: ETV; HBsAg; entecavir; nucleoside analogue; surface antigen