Test Catalog

Test Id : HBCRQ

Hepatitis B Virus Core-Related Antigen, Quantitative, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Monitoring of response to antiviral therapy in individuals with chronic hepatitis B who are negative for hepatitis B e antigen (HBeAg), positive for hepatitis B e antibody , and undetectable or low hepatitis B virus DNA levels (eg, <500 IU/mL) in serum


This test measures the level of hepatitis B (HB) core-related antigen in the serum of patients with chronic hepatitis B (CHB) being monitored for response to antiviral therapy. Such measurement is especially useful in those individuals who are receiving immunotherapy or new antiviral agents to cure CHB with negative HBe antigen, positive HBe antibody, positive HB surface antigen, but undetectable or low hepatitis B virus DNA levels (eg, <500 IU/mL) in serum.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Chemiluminescent Enzyme Immunoassay

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

HBcr Ag, Quantitative, S

Lists additional common names for a test, as an aid in searching


HBcr Ag

HBV cr antigen

HBV core related antigen

Hepatitis B core related antigen

Hepatitis Bcr Ag

Hepatitis Bcr antigen

Specimen Type
Describes the specimen type validated for testing


Ordering Guidance

This test should be requested only in individuals with all of the following:

-Chronic hepatitis B

-Confirmed positive hepatitis B surface (HBs) antigen

-Negative hepatitis B e antigen (HBeAg)

-Positive HBe antibody (anti-HBe)

-Undetectable or low HB viral DNA levels (eg, <500 IU/mL) in serum

Additional Testing Requirements

Testing for hepatitis B virus (HBV) DNA (HBVQN / Hepatitis B Virus [HBV] DNA Detection and Quantification by Real-Time PCR, Serum) and surface antigen (HBAGQ / Hepatitis B Virus Surface Antigen, Quantitative, Serum) levels in serum will be helpful in monitoring response to curative antiviral therapy for chronic hepatitis B.

Shipping Instructions

Ship specimen frozen on dry ice only. If shipment will be delayed for more than 24 hours, freeze serum at -20 degrees to -80 degrees C (up to 60 days) until shipment on dry ice.

Necessary Information

Collection date is required.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 2 mL

Collection Instructions: 

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

2. Transfer serum into aliquot tube.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.5 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

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 Frozen (preferred) 28 days
Refrigerated 14 days
Ambient 7 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Monitoring of response to antiviral therapy in individuals with chronic hepatitis B who are negative for hepatitis B e antigen (HBeAg), positive for hepatitis B e antibody , and undetectable or low hepatitis B virus DNA levels (eg, <500 IU/mL) in serum

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

During antiviral treatment of chronic hepatitis B (CHB), measurement of hepatitis B virus (HBV) DNA in serum or plasma is used as a marker of treatment efficacy, providing an estimate of the viral replicative activity in the treated individual. However, with nucleoside/nucleotide analogues (NA) acting on limited steps of the viral replication cycle, the production of HBV intermediate proteins (such as hepatitis C core antigen [HBcAg], hepatitis B surface antigen [HBsAg], and hepatitis B e antigen [HBeAg]) may not be affected significantly during such treatment. Therefore, measurement of such HBV proteins in serum or plasma can be useful in monitoring treatment efficacy, especially in patients receiving NA therapy when serum or plasma HBV DNA levels are undetectable. Another recently discovered group of HBV intermediate proteins, hepatitis B core-related antigens (HBcrAg), comprises 3 related proteins sharing an identical 149 amino acid sequence: HBcAg, HBeAg, and a truncated 22 kDa precore protein (p22Cr).


HBcrAg in serum or plasma of individuals with CHB showed good correlation with intrahepatic covalently closed circular DNA (cccDNA) and total HBV DNA, serum HBV DNA, and HBsAg to a lesser extent. In situations where serum HBV DNA levels become undetectable or HBsAg loss is achieved, HBcrAg can still be detectable. Serum HBcrAg concentration correlates strongly with the serum HBV DNA concentration in a positive and linear manner, regardless of the HBeAg status. Intrahepatic total HBV DNA also correlates well with serum HBcrAg in treatment-naive or -experienced individuals. For these reasons, HBcrAg in serum or plasma can estimate the intrahepatic cccDNA quantity and serve as a useful marker for disease monitoring, predicting treatment response and disease outcome of CHB.


HBcrAg levels in serum or plasma are also helpful in differentiating HBeAg-negative CHB from HBeAg-positive CHB, predicting spontaneous or treatment-induced HBeAg seroconversion, sustained response to NA therapy, risk of HBV reactivation in occult HBV infection under immunosuppressive therapies, and risk of hepatocellular carcinoma (HCC) development as well as post-operative HCC recurrence.

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.

<1,000 U/mL

Provides information to assist in interpretation of the test results

This assay has a limit of detection of 158 U/mL and quantifies hepatitis B core-related antigen (HBcrAg) in serum within the range of 1000 to 7,500,000 U/mL (or 3.00 log to 6.88 log U/mL).


Result of <1000 U/mL indicates that the HBcrAg level present in the serum specimen tested is less than 1000 U/mL (the lower limit of quantification of this assay). 

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Given the complex kinetics of hepatitis B virus (HBV) replication in chronic hepatitis B, a single undetectable result of HB core-related antigen (HBcrAg) in the serum specimen of an individual receiving antiviral therapy for chronic hepatitis B does not indicate cure or the absence of this virus in this individual. Serial measurements of HBcrAg and other tests, such as HBV DNA (HBVQN / Hepatitis B Virus DNA Detection and Quantification by Real-Time PCR, Serum) and HBsAg (HBAGQ / Hepatitis B Virus Surface Antigen, Quantitative, Serum) levels, would be helpful or necessary to determine the definitive infection status in such individuals.


Performance characteristics have not been established for the following specimen characteristics:

-Grossly icteric (total bilirubin level of >20 mg/dL)

-Grossly lipemic (triolein level of >3000 mg/dL)

-Grossly hemolyzed (hemoglobin level of >500 mg/dL)

-Containing particulate matter

-Cadaveric specimens

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1.Chen EQ, Feng S, Wang ML, et al: Serum hepatitis B core-related antigen is a satisfactory surrogate marker of intrahepatic covalently closed circular DNA in chronic hepatitis B. Sci Rep. 2017;7(1):173. doi: 10.1038/s41598-017-00111-0

2. Zhang ZQ, Zhang XN, Lu W, et al: Distinct patterns of serum hepatitis B core-related antigen during the natural history of chronic hepatitis B. BMC Gastroenterol. 2017;17:140. doi 10.1186/s12876-017-0703-9

3. Mak, LY,Wong DK, Cheung KS, et al: Hepatitis B core-related antigen (HBcrAg): an emerging marker for chronic hepatitis B virus infection. Aliment Pharmacol Ther. 2018;47:43-54. doi: 10.1111/apt.14376

4. Van Halewijn GJ, Geurtsvankessel CH, Klaasse J, et al: Diagnostic and analytical performance of the hepatitis B core related antigen immunoassay in hepatitis B patients. J Clin Virol 2019;114:1-5. doi: 10.1016/j.jcv.2019.03.003

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

Lumipulse G hepatitis B core-related antigen (HBcrAg) is an assay system, including a set of immunoassay reagents, for the detection and quantification of HBcrAg in specimens based on chemiluminescent enzyme immunoassay technology with a two-step immunoassay method on the LUMIPULSE G System. Pre-treatment solution containing a detergent is added to clinical serum specimens, HBcrAg calibrator, and assay controls to the pre-treatment solution. hepatitis B virus (HBV) core-related antibodies present in clinical serum specimens are inactivated in this step. HBcr antibodies-coated particles are then added to the pre-treated clinical specimens, HBcrAg calibrator, and assay controls, followed by incubation. HBcrAg present in each sample specifically bind to HBcr antibodies present on the microparticles to form antigen-antibody immunocomplexes. Excess microparticles and unbound materials are removed by washing, followed by addition and incubation with alkaline phosphatase-labeled HBcr antibodies that specifically binds to HBcrAg in the Ag-Ab immunocomplexes attached to the microparticles to form larger immunocomplexes. After additional washes to remove unbound materials, a substrate solution is added to allow an enzymatic reaction to generate luminescence that is detected by the analyzer. The resulting luminescent signal is proportionate to the amount of HBcrAg present in the sample.(Package insert: Lumipulse G HBcrAg, B314224, ver. 2. Fujirebio Inc; 01/2015)

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.


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.

1 to 7 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


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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 was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

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.


Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports