Test Id : CORAB
Hepatitis B Virus Core Total Antibodies, with Reflex to Hepatitis B Virus Core IgM Antibody, Serum
Useful For
Suggests clinical disorders or settings where the test may be helpful
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
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.
| Test Id | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| HBIM | HBc IgM Ab, S | Yes | No |
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
If the hepatitis B virus core (HBc) total antibodies test result is positive, then anti-HBc IgM testing is performed at an additional charge.
Method Name
A short description of the method used to perform the test
Electrochemiluminescence Immunoassay (ECLIA)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Anti Core Antibodies
Anti-HBc
Anti-Hepatitis Bc
Antibody to Hepatitis Bc
Core Antibody IgG+IgM, S
HBV (Hepatitis B Virus)
Hep Bc Ab IgG/IgM, S
Hepatitis B Core Ab IgG and IgM Antibodies
Hepatitis B Core Ab IgG+IgM, S
Hepatitis B Core Total
Hepatitis B Virus (HBV)
Hepatitis Bc
CORAB
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
If the hepatitis B virus core (HBc) total antibodies test result is positive, then anti-HBc IgM testing is performed at an additional charge.
Specimen Type
Describes the specimen type validated for testing
Serum SST
Necessary Information
Date of collection is required.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
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.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
If not ordering electronically, complete, print, and send 1 of the following:
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
0.6 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
| Heat-inactivated specimen | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum SST | Frozen (preferred) | 90 days | |
| Ambient | 72 hours | ||
| Refrigerated | 6 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
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.
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
If the hepatitis B virus core (HBc) total antibodies test result is positive, then anti-HBc IgM testing is performed at an additional charge.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
During the course of a typical case of acute hepatitis B, hepatitis B virus (HBV) core IgM antibodies (anti-HBc IgM) to HBc 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 HBV surface (HBs) antigen disappears and before anti-HBs appear). Anti-HBc total may be the only serologic marker remaining years after exposure to HBV.
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.
Interpretation
Provides information to assist in interpretation of the test results
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
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
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 more than 20 mg of biotin supplements per day may have false-positive hepatitis B virus core (HBc) 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 HIV. 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
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. LeFevre ML. U.S. Preventive Services Task Force. Screening for hepatitis B virus infection in nonpregnant adolescents and adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2014;161(1):58-66. doi:10.7326/M14-1018
2. WHO guidelines on hepatitis B and C testing. Geneva: World Health Organization; February 2017. Accessed May 5, 2025. Available at www.who.int/publications/i/item/9789241549981
3. Jackson K, Locarnini S, Gish R. Diagnostics of hepatitis B virus: Standard of care and investigational. Clin Liver Dis. 2018;12(1):5-11. doi:10.1002/cld.729
4. Coffin CS, Zhou K, Terrault NA. New and old biomarkers for diagnosis and management of chronic hepatitis B virus infection. Gastroenterology. 2019;156(2):355-368. doi:10.1053/j.gastro.2018.11.037
5. Conners EE, Panagiotakopoulos L, Hofmeister MG, et al. Screening and Testing for Hepatitis B Virus Infection: CDC Recommendations - United States, 2023. MMWR Recomm Rep. 2023;72(1):1-25. doi:10.15585/mmwr.rr7201a1
Method Description
Describes how the test is performed and provides a method-specific reference
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 the anti-HBc in the sample. The remaining unbound sites on the HBcAg become occupied after the addition of biotinylated antibodies and ruthenium complex-labeled antibodies specific to 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. The 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; v2.0, 12/2024)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Saturday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
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- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
86704
86705 (if appropriate)
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| 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
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| CORAB | HBc Total Ab, w/Reflex, S | 13952-7 |