Hepatitis B Surface Antigen
Label Mnemonic: HBSG
Epic code: LAB625
Order form: Laboratory Requisition
Supply order: Supply Order Form
Billing: Billing Policies
CPT code: 87340
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood from light green top tube or TWO Microtainer® devices for pediatric patients.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
Negative
Comments:
Part of initial diagnostic hepatitis profile. May be ordered separately.
Negative: <1.0

Samples with weak but repeatedly positive reactivity (cutoff index greater than or equal to 1.0 but less than or equal to 50) 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 negative surface neutralization reaction indicates that the patient does NOT have a positive surface antigen test. If insufficient sample is available for the neutralization confirmatory test, the pathology resident or attending will contact the ordering physician to discuss the results.
Positive: >50.0
Test Limitations:
Assay is unaffected by icterus (<40 mg/dL), hemolysis (Hb < 2200 mg/dL), lipemia (triglycerides < 2200 mg/dL), and biotin (<1200 ng/mL). 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.

This HBsAg assay is not significantly impacted by high-dose biotin. Studies have shown that serum concentrations of biotin did not exceed 1200 ng/mL in subjects taking a single dose of 300 mg biotin.

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 negative test result does not exclude the possibility of exposure to or infection with hepatitis B. Negative 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. This assay can reliably detect the most common HBsAg genotypes (A through H). In addition, it recognizes various mutants with sequence variability within the "a" determinant region (amino acids 124-147). Testing using alternative methodologies may be warranted if signs, symptoms, and risk factors are indicative of viral hepatitis and other laboratory tests are negative for the presence of viral hepatitis.
Methodology:
Electrochemiluminescence Immunoassay (ECLIA)

Assay updated with increased tolerance to biotin on 8-31-2021.
Sample Processing:
Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells within 1 hour of collection. Send specimen in original tube. Do Not transfer to another tube.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.
Sample Storage:
Refrigerate.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).
Transport Instructions:
Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
CPT Code:
87340
 
See Additional Information:
Biotin Interference with Immunoassays