title: Clinical utility of hepatitis B surface antigen levels during the natural history and treatment of chronic hepatitis B infection.
abstract: BACKGROUND
  Hepatitis B surface antigen (HBsAg) level quantitation may be helpful for understanding the natural history of the disease and its response to treatment.
  
  
  OBJECTIVE
  To determine the serum HBsAg levels during the different phases of chronic hepatitis B (CHB) infection and HBsAg levels of patients who are on treatment with oral antiviral drugs.
  
  
  METHODS
  PATIENTS WERE CATEGORIZED IN FOUR GROUPS: 9 patients in the immune clearance (IC) phase, 46 patients in the inactive carrier (INC) phase, 25 patients in the reactivated HBeAg negative disease (END) phase and 60 HBeAg negative patients who were on treatment with oral antiviral drugs. HBsAg levels were compared between all groups. HBsAg and HBV DNA levels were compared in three phases of HBV infection. Patients on treatment were divided into two groups, taking lamivudine (L) and taking tenofovir (T). HBsAg levels were compared between END, L and T groups.
  
  
  RESULTS
  The HBsAg levels were different between each phase of CHB (p < 0.0001). HBsAg levels were highest in the IC phase and lowest in the INC phase. The HBsAg/HBV DNA ratio was significantly higher in the INC phase than the END and IC phases (p < 0.0001). HBsAg levels were higher in the END phase than the INC phase (p < 0.0001) and higher than the treatment group (p = 0.007). The HBsAg levels had a good correlation with HBV DNA in the natural course of CHB (r = 0.72, p < 0.0001). HBsAg levels were higher in the END group than the L and T groups (p < 0.05). HBsAg levels were higher in the L than the T group (p < 0.05).
  
  
  CONCLUSIONS
  This study demonstrates that HBsAg levels vary during the natural history of chronic hepatitis B infection. Also, the monitoring of HBsAg levels may help us to determine the best management strategy and to decide future treatment algorithms.
authors.affiliation: Department of Gastroenterology, Atatürk Training and Research Hospital, Izmir, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Celik
authors.affiliation: Department of Gastroenterology, Atatürk Training and Research Hospital, Izmir, Turkey.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Arabul
authors.affiliation: Department of Gastroenterology, Atatürk Training and Research Hospital, Izmir, Turkey.
authors.forename: Cem
authors.initials: C
authors.lastname: Cekiç
authors.affiliation: Department of Gastroenterology, Atatürk Training and Research Hospital, Izmir, Turkey.
authors.forename: Sezgin
authors.initials: S
authors.lastname: Vatansever
authors.affiliation: Department of Gastroenterology, Atatürk Training and Research Hospital, Izmir, Turkey.
authors.forename: Serkan
authors.initials: S
authors.lastname: Ipek
authors.affiliation: Department of Gastroenterology, Atatürk Training and Research Hospital, Izmir, Turkey.
authors.forename: Fatih
authors.initials: F
authors.lastname: Aslan
authors.affiliation: Department of Gastroenterology, Atatürk Training and Research Hospital, Izmir, Turkey.
authors.forename: Belkıs
authors.initials: B
authors.lastname: Unsal
keywords: chronic hepatitis B; hepatitis B surface antigen levels
references.citation: Gastroenterology. 2005 Jun;128(7):1890-7
references.pmid: 15940624
references.citation: J Hepatol. 2009 Jun;50(6):1084-92
references.pmid: 19376603
references.citation: J Viral Hepat. 2011 Oct;18(10):e468-74
references.pmid: 21914065
references.citation: Hepatology. 2009 Apr;49(4):1151-7
references.pmid: 19115222
references.citation: Antivir Ther. 2007;12(1):73-82
references.pmid: 17503750
references.citation: JAMA. 1965 Feb 15;191:541-6
references.pmid: 14239025
references.citation: J Hepatol. 2010 Apr;52(4):514-22
references.pmid: 20207438
references.citation: Clin Gastroenterol Hepatol. 2007 Dec;5(12):1462-8
references.pmid: 18054753
references.citation: J Hepatol. 2010 Apr;52(4):508-13
references.pmid: 20206400
references.citation: J Hepatol. 2010 Apr;52(4):475-7
references.pmid: 20185190
references.citation: Antivir Ther. 2007;12(3):381-8
references.pmid: 17591028
references.citation: Hepatology. 2010 Oct;52(4):1232-41
references.pmid: 20648555
references.citation: Antivir Ther. 2009;14(4):489-99
references.pmid: 19578234
references.citation: J Hepatol. 2009 Feb;50(2):227-42
references.pmid: 19054588
references.citation: Gastroenterology. 2010 Aug;139(2):483-90
references.pmid: 20451520
references.citation: J Med Virol. 2009 Aug;81(8):1336-42
references.pmid: 19551826