Hepatitis B Surface Antigen
| Order Code: | HBSG |
| Epic Lab Code: | LAB625 |
| Order Form: | A-1a General Lab or Epic Req |
Chemistry
6240 RCP
356-3527
6240 RCP
356-3527
Specimen:
Plasma
Collection Medium:
 |
| Plasma Separator Tube |
Alternate
Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood from light green top tube or TWO microtainers for
pediatric patients.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Analytic Time:
1 hour (upon receipt in laboratory)
Reference Range:
Non-reactive
Comments:
Part of initial diagnostic hepatitis profile. May be ordered
separately.
Samples with weak but repeatedly positive reactivity (cutoff index greater than or equal to 1.0 but less than or equal to 20) will be resulted as "GRAYZONE". If sufficient specimen is available, samples with GRAYZONE reactivity will be analyzed by the hepatitis B surface antigen neutralization test (a confirmatory test) by a reference laboratory. A non-reactive surface neutralization reaction indicates that the patient does NOT have a positive surface antigen test. If insufficient is available for the neutralization confirmatory test, the pathology resident or attending will contact the ordering physician to discuss the results.
Refer to University of Iowa Health Care policies: Policy for Significant Exposure of a Care Provider - contains information about staff member and source patient testing when there has been as significant exposure of a care provider.
Policy Governing HIV Testing Education, Testing, Reporting and Confidentiality - contains information about patient testing for HIV.
New analytical immunoassay instituted April 5, 2010.
Samples with weak but repeatedly positive reactivity (cutoff index greater than or equal to 1.0 but less than or equal to 20) will be resulted as "GRAYZONE". If sufficient specimen is available, samples with GRAYZONE reactivity will be analyzed by the hepatitis B surface antigen neutralization test (a confirmatory test) by a reference laboratory. A non-reactive surface neutralization reaction indicates that the patient does NOT have a positive surface antigen test. If insufficient is available for the neutralization confirmatory test, the pathology resident or attending will contact the ordering physician to discuss the results.
Refer to University of Iowa Health Care policies: Policy for Significant Exposure of a Care Provider - contains information about staff member and source patient testing when there has been as significant exposure of a care provider.
Policy Governing HIV Testing Education, Testing, Reporting and Confidentiality - contains information about patient testing for HIV.
New analytical immunoassay instituted April 5, 2010.
Test
Limitations:
Assay is unaffected by icterus, hemolysis (Hb < 1400 mg/dL), and
lipemia (triglycerides < 1500 mg/dL). In patients receiving high
biotin doses
(> 5 mg/day) no sample should be taken until at least 8 hours after the last biotin administration. No false negative findings due to the high- dose hook effect are observed up to a HBsAg concentration of 1.5 million IU/mL. In rare cases, interference due to extremely high titers of antibodies to analyte-specific antibodies, streptavidin, or ruthenium can occur.
For diagnostic purposes, the results should always be assessed in conjunction with the patient's medical history, clinical examination, and other findings. The assay is not intended for use in screening blood bank donors. A nonreactive test result does not exclude the possibility of exposure to or infection with hepatitis B. Nonreactive test results in individuals with prior exposure to hepatitis B may be due to antigen levels below the detection limit of this assay or lack of antigen reactivity to the antibodies used in this assay.
False positive reactions may occur rarely in patients with rheumatologic disease (due to presence of auto-antibodies) or in kidney failure. Individuals recently vaccinated for hepatitis B may give a transient positive result for HBsAg because of its presence in the vaccine. The ability of the Elecsys HBsAg assay to detect hepatitis B virus mutants has not been determined. Testing using alternative methodologies may be warranted if signs, symptoms, and risk factors are indicative of viral hepatitis and other laboratory tests are nonreactive for the presence of viral hepatitis.
(> 5 mg/day) no sample should be taken until at least 8 hours after the last biotin administration. No false negative findings due to the high- dose hook effect are observed up to a HBsAg concentration of 1.5 million IU/mL. In rare cases, interference due to extremely high titers of antibodies to analyte-specific antibodies, streptavidin, or ruthenium can occur.
For diagnostic purposes, the results should always be assessed in conjunction with the patient's medical history, clinical examination, and other findings. The assay is not intended for use in screening blood bank donors. A nonreactive test result does not exclude the possibility of exposure to or infection with hepatitis B. Nonreactive test results in individuals with prior exposure to hepatitis B may be due to antigen levels below the detection limit of this assay or lack of antigen reactivity to the antibodies used in this assay.
False positive reactions may occur rarely in patients with rheumatologic disease (due to presence of auto-antibodies) or in kidney failure. Individuals recently vaccinated for hepatitis B may give a transient positive result for HBsAg because of its presence in the vaccine. The ability of the Elecsys HBsAg assay to detect hepatitis B virus mutants has not been determined. Testing using alternative methodologies may be warranted if signs, symptoms, and risk factors are indicative of viral hepatitis and other laboratory tests are nonreactive for the presence of viral hepatitis.
Methodology:
Electrochemiluminescence Immunoassay (ECLIA)
CPT Code:
87340