title: Factors associated with natural seroclearance of hepatitis B surface antigen and prognosis after seroclearance: a prospective follow-up study.
abstract: OBJECTIVE
  Although the natural seroclearance rate of Hepatitis B surface antigen (HBsAg) is reported to be 0.4-2% in western countries, this is not well known in Korea. This study aimed to elucidate the rate of natural HbsAg seroclearance, factors associated with seroclearance and prognosis after seroclearance.
  
  
  METHODS
  In 1999, 250 chronic HBsAg carriers without any history of antiviral treatment and without any evidence of liver cirrhosis or hepatocellular carcinoma were selected. Follow-up HBsAg/ anti-HBs tests were performed annually till 2004. During a mean follow-up period of 48 months, 24 patients were lost and 11 received antiviral treatment. Finally, 215 patients completed the study.
  
  
  RESULTS
  HBsAg seroclearance was observed in 11 patients (6 males, 5 females). One-year seroclearance rate was 1.4%. All patients who achieved seroclearance were HBeAg (-)/HBV DNA (-) at the time of enrollment. Additionally, old age and normal serum alanine aminotransferase (ALT) level were the factors associated with seroclearance (p < 0.05, respectively). During the follow-up period, only mild transient elevations of ALT were observed in 4 patients and no serious complications were observed.
  
  
  CONCLUSIONS
  Natural seroclearance occurred exclusively in patients who were HBeAg (-)/HBV-DNA (-), and annual rate of natural HBsAg seroclearance was 1.4%. No significant complications were observed after seroclearance.
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Jeong Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Joon Hyoek
authors.initials: JH
authors.lastname: Lee
authors.forename: Sang Jong
authors.initials: SJ
authors.lastname: Park
authors.forename: Mun Hee
authors.initials: MH
authors.lastname: Bae
authors.forename: Ji Hyang
authors.initials: JH
authors.lastname: Kim
authors.forename: Do Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Jong Kyu
authors.initials: JK
authors.lastname: Kim
authors.forename: Moon Seok
authors.initials: MS
authors.lastname: Choi
authors.forename: Kwang Cheol
authors.initials: KC
authors.lastname: Koh
authors.forename: Seung Woon
authors.initials: SW
authors.lastname: Paik
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Yoo
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006801:Humans; D007723:Korea; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D006514:Hepatitis B Surface Antigens