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HelpTest Code CORAB Hepatitis B Virus Core Total Antibodies, with Reflex to Hepatitis B Virus Core IgM Antibody, Serum
Reporting Name
HBc Total Ab, w/Reflex, SUseful For
Detection and differentiation between recent, past/resolved, or chronic hepatitis B
Diagnosis of recent hepatitis B virus (HBV) infection during the "window period" when both hepatitis B surface (HBs) antigen and anti-HBs are negative
This test is not useful for determining immunity to or recovery from HBV infection.
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| HBIM | HBc IgM Ab, S | Yes | No |
Testing Algorithm
If the hepatitis B virus core (HBc) total antibodies test result is positive, then anti-HBc IgM is performed at an additional charge.
Method Name
Electrochemiluminescence Immunoassay (ECLIA)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Serum SSTNecessary Information
Date of collection is required.
Specimen Required
Patient Preparation: For 24 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).
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: 0.7 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
0.6 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum SST | Frozen (preferred) | 90 days | |
| Refrigerated | 6 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
| Heat-inactivated specimen | Reject |
Special Instructions
Reference Values
Negative
Interpretation depends on clinical setting.
Day(s) Performed
Monday through Saturday
CPT Code Information
86704
86705 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CORAB | HBc Total Ab, w/Reflex, S | 13952-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CORAB | HBc Total Ab, w/Reflex, S | 13952-7 |
Clinical Information
During the course of a typical case of acute hepatitis B, hepatitis B virus (HBV) core IgM antibodies (anti-HBc IgM) to hepatitis B virus core antigen are present in the serum shortly before clinical symptoms appear. Anti-HBc total is detectable during the prodromal, acute, and early convalescent phases when it exists as anti-HBc IgM. Anti-HBc IgM increase in level and are present during the core window period (ie, after hepatitis B virus surface (HBs) antigen disappears and before anti-HBs appear). Anti-HBc total may be the only serologic marker remaining years after exposure to HBV.
Interpretation
Negative hepatitis B virus core total antibody (anti-HBc total) results indicate the absence of recent, past/resolved, or chronic hepatitis B.
Positive anti-HBc total result may indicate recent, past/resolved, or chronic hepatitis B.
Testing for anti-HBc IgM is necessary to confirm the presence of acute or recent hepatitis B. A positive anti-HBc total result with a negative anti-HBc IgM result indicates past or chronic hepatitis B virus (HBV) infection. Differentiation between past/resolved and chronic hepatitis B can be based on the presence of hepatitis B virus surface antigen (HBsAg) in the latter condition.
Positive anti-HBc total results with negative anti-HBc IgM results in infants younger than 18 months may be due to passively acquired maternal IgG antibodies. Additional testing, such as HBsAg, anti-HBc IgM, and hepatitis Be antigen, are necessary to confirm a diagnosis of acute or recent hepatitis B in these infants.
Cautions
This assay has not been licensed by the US Food and Drug Administration  for the screening of blood, plasma, and tissue donors.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination, and other findings.
Serum specimens from individuals taking biotin supplements of 20 mg or more per day may have false-positive hepatitis B core total antibody test results due to interference of biotin with the assay. Such individuals should stop taking these biotin-containing dietary supplements for a minimum of 12 hours before blood collection for this test.
Current methods for the detection of antibodies to HBc may not detect all infected individuals. A nonreactive test result does not exclude the possibility of exposure to hepatitis B virus. In rare cases, interference due to high titers of antibodies to immunological components, streptavidin or ruthenium can occur.
Specimens containing sodium azide may cause false-positive results and should not be tested. Lipemic and precipitated samples may give inconsistent results.
 False positive results may also occur in a limited number of patients positive for antibodies to hepatitis C virus, hepatitis E virus, human T-cell lymphotropic virus, and human immunodeficiency virus. A reactive anti-HBc result does not exclude co-infection by another hepatitis virus.
Negative anti-HBc results may occur during early infection due to delayed seroconversion or low antibody levels below the detection limit of this assay or if the patient’s antibodies do not react with the antigen used in this test.
Results obtained with the Elecsys Anti-HBc II immunoassay may not be used interchangeably with values obtained with different manufacturers’ assay methods.
Assay performance characteristics have not been established for the following specimen characteristics or specimen types:
-Patients younger than 21 years, pregnant women, or in populations of immunocompromised or immunosuppressed patients
-Grossly icteric (total bilirubin level of >25 mg/dL)
-Grossly lipemic (intralipid level of >1000 mg/dL)
-Grossly hemolyzed (hemoglobin level of >800 mg/dL)
-Containing particulate matter
-Cadaveric specimens
-Heat-inactivated specimens
-Specimen types other than serum
Method Description
The Elecsys Anti-HBc (hepatitis B virus core antibody) II assay is based on the competitive immunoassay principle and performed using an electrochemiluminescence immunoassay on the automated cobas e 801 immunochemistry analyzer. The patient's sample is pretreated first with a reducing reagent, and after the addition of synthetic HBc antigen (HBcAg), complexes are formed with anti-HBc in the sample. The remaining unbound sites on the HBcAg become occupied after addition of biotinylated antibodies and ruthenium complex-labeled antibodies specific for HBcAg. The entire complex binds to the streptavidin-coated microparticles (solid phase) via interaction of biotin and streptavidin. The reaction mixture is then aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. After unbound substances are washed away, voltage is applied to the electrode that induces chemiluminescent emissions, which are measured by a photomultiplier. Test result is determined by comparing the electrochemiluminescence signal generated from the reaction product in the sample to the cutoff index value set from assay reagent lot-specific assay calibration.(Package insert: Elecsys Anti-HBc II. Roche Diagnostics; v1.0, 04/2022)