Test Code HBNTP Hepatitis B Virus Surface Antigen Confirmation, Prenatal, Serum

Useful For

Diagnosis of acute, recent, or chronic hepatitis B in prenatal patients

This test is not useful during the "window period" of acute hepatitis B (ie, after disappearance of hepatitis B virus surface antigen [HBsAg] and prior to appearance of HBs antibody).

This test is not suitable as stand-alone prenatal screening test of HBsAg status in pregnant women.

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

Reporting Name

HBs Ag Confirmation Prenatal, S

Specimen Type

Serum SST

Ordering Guidance

Specimen Required

Only orderable as a reflex. For more information see HBAGP / Hepatitis B Virus Surface Antigen Prenatal, Serum.

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Serum gel (red-top tubes are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 0.8 mL

Collection Instructions:

1. Centrifuge blood collection tube per manufacturer's instructions (eg, centrifuge and aliquot within 2 hours of collection for BD Vacutainer tubes).

2. Aliquot serum into a plastic vial.

Specimen Minimum Volume

0.7 mL

Specimen Stability Information

Specimen Type	Temperature	Time
Serum SST	Frozen (preferred)	90 days
	Refrigerated	6 days
	Ambient	72 hours

Reject Due To

Gross hemolysis	Reject
Gross lipemia	Reject
Gross icterus	Reject

Clinical Information

Hepatitis B virus (HBV) is a DNA virus that is endemic throughout the world. The infection is spread primarily through percutaneous contact with infected blood products (eg, blood transfusion, sharing of needles among injection drug users). The virus is found in various human body fluids, and it is known to be spread through oral and genital contact. 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 8 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 more than 6 months in duration indicates development of either a chronic carrier state or chronic HBV infection.

For more information see:

-Hepatitis B: Testing Algorithm for Screening, Diagnosis, and Management

-HBV Infection-Monitoring Before and After Liver Transplantation

-Viral Hepatitis Serologic Profiles

Interpretation

A reactive screen result (cutoff index values ≥1.00) confirmed as positive by a hepatitis B surface antigen (HBsAg) confirmatory test is indicative of acute or chronic hepatitis B or chronic hepatitis B virus (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. If clinically indicated, repeat testing, at a later date, is recommended.

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

Cautions

This assay has not been licensed by the US Food and Drug Administration Â for the screening of blood, plasma, and tissue donors.

For diagnostic purposes, results should always be assessed in conjunction with the patientâ€™s medical history, clinical examination, and other findings.

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

Positive HBsAg test results will need to be reported by the healthcare provider to their state department of health surveillance units, as required by law in some states.

Current methods for the detection of HBsAg may not detect all infected individuals.

A negative test result does not exclude with certainty a possible exposure to or on infection with the hepatitis B virus (HBV). Negative test results obtained for persons with a past exposure may be caused by an antigen concentration below the detection limit of this assay or the lack of reactivity of the antigens to the antibodies used in this assay.

Performance characteristics of this assay have not been established for testing of newborns or when used in conjunction with other manufacturersâ€™ assays for specific HBV serological markers.

Assay performance characteristics have not been established for the following specimen characteristics or specimen types:

-Grossly icteric (total bilirubin level of >40 mg/dL)

-Grossly lipemic (Intralipid level of >2200 mg/dL)

-Grossly hemolyzed (hemoglobin level of >2200 mg/dL)

-Containing particulate matter

-Cadaveric specimens

-Specimen types other than serum

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

87341

LOINC Code Information

Test ID	Test Order Name	Order LOINC Value
HBNTP	HBs Ag Confirmation Prenatal, S	7905-3

Result ID	Test Result Name	Result LOINC Value
HBNTP	HBs Ag Confirmation Prenatal, S	7905-3

Method Name