EBM Consult

Lab Test: Hepatitis B Surface Antigen Level

    Lab Test
    • Hepatitis B Surface Antigen
    Description
    • Detection of serologic marker on surface of hepatitis B virus (HBsAg) for evaluation of current hepatitis B infection
    Reference Range
    • Negative (limits of detection 0.02-10 ng/mL)
    Indications & Uses
    • Suspected acute or chronic type B viral hepatitis - the finding of hepatitis B surface antigen (HBsAg) without other serologic markers indicates (1) acute hepatitis B, (2) superimposed hepatitis A in a chronic HBV carrier, or (3) reactivation of chronic
      • HBsAg can be identified in serum 30-60 days after exposure to hepatitis B virus (HBV) and persists for variable periods.  It rises rapidly during the first 1-3 weeks of the presymptomatic stage and persists during the icteric and symptomatic phase of acute illness, peaking at or shortly after the increase in liver function tests.
      • HBsAg typically becomes undetectable in early convalescence (1-3 months after onset of jaundice), but it may persist for up to 6 months if high titers occur early.  After HBsAg disappears, antibody to HBsAg (anti-HBs) appears, indicating recovery and immunity to reinfection.
      • The presence of HBsAg for 6 months or more is diagnostic for chronic HBV.  Patients with chronic HBV usually have continuing levels of HBsAg, often for life, plus detectable levels of HBV DNA, indicating viremia and conferring chronic carrier status.
    Clinical Application

    Commercial diagnostic assays vary in their ability to detect expressed hepatitis B surface antigen (HBsAg) variants.

    Related Tests
    • Acute hepatitis panel
    • Hepatitis chronic carrier panel
    • Prenatal screening panel
    • Transplant panel
    Test Tube Needed
    • Red top tube
    Procedure
    • Collect serum sample.
    Storage and Handling
    • May keep serum at room temperature for up to 7 days; for longer storage, freeze at 4°C or -20°C.
    References
    • Elgouhari HM, et al. Hepatitis B: a strategy for evaluation and management. Cleve Clin J Med 2009;76:19-35.
    • Kuo A et al. Chronic hepatitis B infection. Clin Liver Dis 2012;16:347-369.
    • LaGow B et al., eds. PDR Lab Advisor. A Comprehensive Point-of-Care Guide for Over 600 Lab Tests.  First ed. Montvale, NJ: Thomson PDR; 2007.
    • World Health Organization website. Hepatitis B.

MESH Terms & Keywords

  • Hepatitis B, Surface, Antigen