Mobile Site ›
Print Friendly View

Test ID: HBAG    
Hepatitis B Surface Antigen, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosis of acute, recent, or chronic hepatitis B infection

 

Determination of chronic hepatitis B infection status

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Hepatitis B virus (HBV) is endemic throughout the world. The infection is spread primarily through percutaneous contact with infected blood products (eg, blood transfusion, sharing of needles by intravenous drug addicts). The virus is also found in various human body fluids, and it is known to be spread through oral and genital contacts. HBV can be transmitted from mother to child during delivery through contact with blood and vaginal secretions, but it is not commonly transmitted transplacentally.

                          

Hepatitis B surface antigen (HBsAg) is the first serologic marker appearing in the serum at 6 to 16 weeks following exposure to HBV. In acute infection, HBsAg usually disappears in 1 to 2 months after the onset of symptoms. Persistence of HBsAg for >6 months in duration indicates development of either a chronic carrier state or chronic HBV infection.

 

See The Laboratory Approach to the Diagnosis and Monitoring of Hepatitis B Infection in Publications.

See the following in Special Instructions:

-HBV Infection-Diagnostic Approach and Management Algorithm

-HBV Infection-Monitoring Before and After Liver Transplantation

-Viral Hepatitis Serologic Profile

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

See Viral Hepatitis Serologic Profiles in Special Instructions.

Interpretation Provides information to assist in interpretation of the test results

A reactive screen result (signal to cutoff ratio [S/CO] > or =1.00, but < or =50.0) confirmed as positive by hepatitis B surface antigen (HBsAg) confirmatory test (see Method Description) or a positive screen result (S/CO >50.0) is indicative of acute or chronic hepatitis B virus (HBV) infection, or chronic HBV carrier state.

 

Specimens with reactive screen results but negative (ie, not confirmed) HBsAg confirmatory test results are likely to contain cross-reactive antibodies from other infectious or immunologic disorders. Repeat testing is recommended at a later date if clinically indicated.

 

Confirmed presence of HBsAg is frequently associated with HBV replication and infectivity, especially when accompanied by presence of hepatitis B envelope (HBe) antigen and/or detectable HBV DNA.

 

See the following in Special Instructions:

-HBV Infection-Diagnostic Approach and Management Algorithm

-HBV Infection-Monitoring Before and After Liver Transplantation

-Viral Hepatitis Serologic Profile

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test is not offered as a screening or confirmatory test for blood donor specimens.

 

Not useful during "window period" of acute hepatitis B virus (HBV) infection (ie, after disappearance of hepatitis B surface antigen [(HBsAg] and prior to appearance of hepatitis B surface antibody [anti-HBs]). Testing for acute HBV infection should also include hepatitis B core IgM antibody (anti-HBc IgM).

 

Positive screen results (ie, S/CO >50.0) without need for confirmation testing should be interpreted in conjunction with test results of other HBV serologic markers (eg, anti-HBs, anti-HBc total, and anti-HBc IgM).

 

Not suitable as stand-alone prenatal screening test of HBsAg status in pregnant women.

 

Positive HBsAg test results should be reported by the health care provider to the State Department of Health, as required by law in some states.

 

Individuals, especially neonates and children, who recently received hepatitis B vaccination may have transient positive HBsAg test results because of the large dose of HBsAg used in the vaccine relative to the individual's body mass.

 

Performance characteristics have not been established for the following specimen characteristics:

-Grossly icteric (total bilirubin level of >20 mg/dL)

-Grossly lipemic (triolein level of >3,000 mg/dL)

-Grossly hemolyzed (hemoglobin level of >500 mg/dL)

-Containing particulate matter

-Cadaveric specimens

Clinical Reference Provides recommendations for further in-depth reading of a clinical nature

1. Servoss JC, Friedman LS: Serologic and molecular diagnosis of hepatitis B virus. Clin Liver Dis 2004;8:267-281

2. Badur S, Akgun A: Diagnosis of hepatitis B infections and monitoring of treatment. J Clin Virol 2001;21:229-237

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test