Elecsys Anti-HBc II

K260046 · Roche Diagnostics · SEI · Apr 7, 2026 · Microbiology

Device Facts

• Record ID: K260046
• Device Name: Elecsys Anti-HBc II
• Applicant: Roche Diagnostics
• Product Code: SEI · Microbiology
• Decision Date: Apr 7, 2026
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3173
• Device Class: Class 2
• Attributes: Pediatric

Indications for Use

Immunoassay for the in vitro qualitative determination of total antibodies to hepatitis B core antigen (anti-HBc) in human serum and plasma (lithium heparin, sodium citrate, potassium EDTA) from adult and pediatric (2 through 21 years of age) patients with the symptoms of hepatitis or who may be at risk for hepatitis B virus (HBV) infection. The detection of total anti-HBc is indicative of a laboratory diagnosis for HBV infection. Further HBV serological marker testing is required to define the specific disease state. The immunoassay's performance has not been established for the monitoring of HBV disease or therapy. The electrochemiluminescence immunoassay “ECLIA” is intended for use on cobas e immunoassay analyzers.

Device Story

Elecsys Anti-HBc II is a qualitative, competitive electrochemiluminescence immunoassay (ECLIA) for detecting total anti-HBc antibodies in human serum/plasma. Performed on cobas e immunoassay analyzers, the process involves sample pretreatment with a reducing agent, followed by incubation with HBcAg, biotinylated antibodies, ruthenium-labeled antibodies, and streptavidin-coated microparticles. The complex is magnetically captured on an electrode; voltage application induces chemiluminescence measured by a photomultiplier. Results are automatically calculated by comparing sample signals to a calibrated cut-off. Used in clinical laboratories by trained personnel to aid in HBV infection diagnosis. Output informs clinicians on the presence of anti-HBc antibodies, necessitating further serological testing for disease staging.

Clinical Evidence

Clinical evidence includes a prospective study of 119 pediatric participants (ages 2-21) at risk for HBV. The study demonstrated 100% Negative Percent Agreement (NPA) (95% CI: 96.9-100). No positive specimens were identified in the prospective cohort. A supplemental spiking study using 30 negative pediatric samples and adult controls confirmed performance, with mean absolute differences of 0.0107 COI, meeting the ≤ 0.20 COI acceptance criteria.

Technological Characteristics

Qualitative competitive ECLIA; utilizes Tris(2,2'-bipyridyl) ruthenium (II)-complex. Analyzers: cobas e series. Automated specimen handling via barcode. Calibration/QC: AHBC2 Cal1/Cal2 and PreciControl Anti-HBc II. Software-based automated signal processing and cut-off comparison.

Indications for Use

Indicated for adult and pediatric (2-21 years) patients with hepatitis symptoms or at risk for HBV infection. Used for qualitative detection of total anti-HBc antibodies to aid in HBV diagnosis. Not for monitoring disease or therapy.

Regulatory Classification

Identification

A hepatitis B virus (HBV) antibody assay is identified as an in vitro diagnostic device intended for prescription use in the detection of antibodies to HBV in human serum, plasma, or other matrices, and as a device that aids in the diagnosis of HBV infection in persons with signs and symptoms of hepatitis and in persons at risk for hepatitis B infection. Results from assays may be qualitative or quantitative, such as quantitative anti-HBs. In addition, results from an anti-HBc IgM (IgM antibodies to core antigen) assay indicating the presence of anti-HBc IgM are indicative of recent HBV infection. Anti-HBs (antibodies to surface antigen) assay results may be used as an aid in the determination of susceptibility to HBV infection in individuals prior to or following HBV vaccination or when vaccination status is unknown. The assay is not intended for screening of blood, plasma, cells, or tissue donors. The assay is intended as an aid in diagnosis in conjunction with clinical findings and other diagnostic procedures.

Special Controls

*Classification.* Class II (special controls). The special controls for this device are:(1) The labeling required under § 809.10(b) of this chapter must include: (i) A prominent statement that the assay is not intended for the screening of blood, plasma, cells, or tissue donors. (ii) A detailed explanation of the principles of operation and procedures for performing the assay. (iii) A detailed explanation of the interpretation of results. (iv) Limitations, which must be updated to reflect current clinical practice and disease presentation and management. The limitations must include statements that indicate: (A) When appropriate, performance characteristics of the assay have not been established in populations of immunocompromised or immunosuppressed patients or other special populations where assay performance may be affected. (B) Detection of HBV antibodies to a single viral antigen indicates a present or past infection with hepatitis B virus, but does not differentiate between acute, chronic, or resolved infection. (C) The specimen types for which the device has been cleared, and that use of the assay with specimen types other than those specifically cleared for this device may result in inaccurate assay results. (D) Diagnosis of hepatitis B infection should not be established on the basis of a single assay result but should be determined by a licensed healthcare professional in conjunction with the clinical presentation, history, and other diagnostic procedures. (E) A non-reactive assay result may occur early during acute infection, prior to development of a host antibody response to infection, or when analyte levels are below the limit of detection of the assay. (F) Results obtained with this assay may not be used interchangeably with results obtained with a different manufacturer's assay. (v) For devices intended for the quantitative detection of HBV antibodies (anti-HBs), in addition to the special controls listed in paragraphs (b)(1) and (2) of this section, labeling required under § 809.10(b) of this chapter must include: (A) The assay calibrators' traceability to a standardized reference material that FDA has determined is appropriate ( *e.g.,* a recognized consensus standard) and the limit of blank (LoB), limit of detection (LoD), limit of quantitation (LoQ), linearity, and precision to define the analytical measuring interval.(B) Performance results of the analytical sensitivity study testing a standardized reference material that FDA has determined is appropriate ( *e.g.,* a recognized consensus standard).(2) Design verification and validation must include the following: (i) Detailed device description, including all parts that make up the device, ancillary reagents required but not provided, an explanation of the device methodology, and design of the antigen(s) and capture antibody(ies) sequences, rationale for the selected epitope(s), degree of amino acid sequence conservation of the target, and the design and composition of all primary, secondary and subsequent standards used for calibration. (ii) Documentation and characterization ( *e.g.,* supplier, determination of identity, and stability) of all critical reagents (including description of the antigen(s) and capture antibody(ies)), and protocols for maintaining product integrity throughout its labeled shelf life.(iii) Risk analysis and management strategies, such as Failure Modes Effects Analysis and/or Hazard Analysis and Critical Control Points summaries and their impact on assay performance. (iv) Final release criteria to be used for manufactured assay lots with appropriate evidence that lots released at the extremes of the specifications will meet the identified analytical and clinical performance characteristics as well as stability. (v) Stability studies for reagents must include documentation of an assessment of real-time stability for multiple reagent lots using the indicated specimen types and must use acceptance criteria that ensure that analytical and clinical performance characteristics are met when stability is assigned based on the extremes of the acceptance range. (vi) All stability protocols, including acceptance criteria. (vii) When applicable, analytical sensitivity of the assay that is the same or better than that of other cleared or approved assays. (viii) Analytical performance studies and results for determining the limit of blank (LoB), limit of detection (LoD), cutoff, precision (reproducibility), including lot-to-lot and/or instrument-to-instrument precision, interference, cross reactivity, carryover, hook effect, seroconversion panel testing, matrix equivalency, specimen stability, reagent stability, and cross-genotype antibody detection sensitivity, when appropriate. (ix) For devices intended for the detection of antibodies for which a standardized reference material (that FDA has determined is appropriate) is available, the analytical sensitivity study and results testing the standardized reference material. Detailed documentation of that study and its results must be provided, including the study protocol, study report, testing results, and all statistical analyses. (x) For devices with associated software or instrumentation, documentation must include a detailed description of device software, including software applications and hardware-based devices that incorporate software. The detailed description must include documentation of verification, validation, and hazard analysis and risk assessment activities, including an assessment of the impact of threats and vulnerabilities on device functionality and end users/patients as part of cybersecurity review. (xi) Detailed documentation of clinical performance testing from a clinical study with an appropriate number of HBV reactive and non-reactive samples in applicable risk categories and conducted in the appropriate settings by the intended users. Performance must be analyzed relative to an FDA cleared or approved HBV antibody assay or a comparator that FDA has determined is appropriate. Additional relevant patient groups must be validated as appropriate. The samples must include prospective (sequential) samples for each identified specimen type and, as appropriate, additional characterized clinical samples. Samples must be sourced from geographically diverse areas. (3) For any HBV antibody assay intended for quantitative detection of anti-HBV antibodies, the following special controls, in addition to those special controls listed in paragraphs (b)(1) and (2) of this section, also apply: (i) Detailed documentation of the metrological calibration traceability hierarchy to a standardized reference material that FDA has determined is appropriate. (ii) Detailed documentation of the following analytical performance studies conducted, as appropriate to the technology, specimen types tested, and intended use of the device, including upper and lower limits of quantitation (UloQ and LloQ, respectively), linearity using clinical samples, and an accuracy study using the recognized international standard material.

Predicate Devices

• Abbott ARCHITECT CORE (P080023)

Submission Summary (Full Text)

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FDA

U.S. FOOD & DRUG

ADMINISTRATION

510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION

# DECISION SUMMARY

ASSAY AND INSTRUMENT

## I Background Information:

A 510(k) Number

K260046

B Applicant

Roche Diagnostics

C Proprietary and Established Names

Elecsys Anti-HBc II

D Regulatory Information

| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| SEI | II | 21 CFR 866.3173
Hepatitis B virus antibody assays | MI- Microbiology |

## II Submission/Device Overview:

A Purpose for Submission:

To obtain clearance for the Elecsys Anti-HBc II assay's addition of pediatric (2 through 21 years of age) population to the indications for use.

B Measurand:

Total antibodies to hepatitis B core antigen (anti-HBc)

C Type of Test:

Qualitative electrochemiluminescence immunoassay (ECLIA)

## III Intended Use/Indications for Use:

A Intended Use(s):

See Indications for Use below.

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

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B Indication(s) for Use:

Immunoassay for the in vitro qualitative determination of total antibodies to hepatitis B core antigen (anti-HBc) in human serum and plasma (lithium heparin, sodium citrate, potassium EDTA) from adult and pediatric (2 through 21 years of age) patients with the symptoms of hepatitis or who may be at risk for hepatitis B virus (HBV) infection. The detection of total anti-HBc is indicative of a laboratory diagnosis for HBV infection. Further HBV serological marker testing is required to define the specific disease state. The immunoassay's performance has not been established for the monitoring of HBV disease or therapy.

The electrochemiluminescence immunoassay “ECLIA” is intended for use on cobas e immunoassay analyzers.

C Special Conditions for Use Statement(s):

Rx – For Prescription Use Only

D Special Instrument Requirements:

For use with the cobas e immunoassay analyzers

IV Device/System Characteristics:

A Device Description:

Elecsys Anti-HBc II is a qualitative, serological, competitive assay with a total test time of 27 minutes. The assay is based on competition principle with a pretreatment step. First, the sample is incubated with a reducing agent. During the second incubation, HBcAg is added to form a complex with the anti-HBc antibodies. In the third incubation, biotinylated antibodies specific for HBcAg, along with ruthenium complex-labeled antibodies, are added to occupy the remaining binding sites on the HBcAg. The addition of streptavidin-coated microparticles bridges the entire complex to the solid phase, allowing the detection of the anti-HBc antibody-HBcAg complex via electrochemiluminescence.

The microparticles are magnetically captured on the surface of an electrode and the bound complex is washed. Application of a voltage to the electrode induces chemiluminescence, which is measured by a photomultiplier. Results are determined automatically by the Elecsys software by comparing the electrochemiluminescence signal obtained from the sample with the signal of the cut-off value previously obtained by Anti-HBc calibration.

PreciControl Anti-HBc II contains ready-for-use control serum based on human serum. The controls are used for monitoring the accuracy of the Elecsys Anti-HBc II immunoassay. The controls, 1 (negative) and 2 (positive) contain IgG and IgM Anti-HBc antibodies in human serum. These controls are packaged and sold separately from the Anti-HBc II immunoassay.

B Principle of Operation:

Competition principle. Total duration of assay: 27 minutes.

- First incubation: Pretreatment of 40 µL of sample with reducing agent
- Second incubation: After addition of HBcAg, a complex is formed with anti HBc antibodies in the sample.

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- Third incubation: After addition of biotinylated antibodies and ruthenium complex, labeled antibodies specific for HBcAg, together with streptavidin-coated microparticles, the still free binding sites on the HBc antigens become occupied. The entire complex becomes bound to the solid phase via interaction of biotin and streptavidin.

- The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell M. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier.

- Results are determined automatically by the software by comparing the electrochemiluminescence signal obtained from the reaction product of the sample with the signal of the cutoff value previously obtained by calibration.

a) Tris(2,2'-bipyridyl) ruthenium (II)-complex (Ru(bpy))

## Interpretation of results

| Initial Elecsys Anti-HBc II assay result | | | |
| --- | --- | --- | --- |
| COI | Result | Interpretation of results | Retest procedure |
| > 1.1 | Non-reactive^{A)} | No antibodies to HBc were detected | No retest required |
| 1.1 ≥ COI > 0.9 | Border | Borderline zone (undetermined) | Retest in duplicate with the Elecsys Anti-HBc II assay |
| ≤ 0.9 | Reactive | Antibodies to HBc detected | Follow CDC recommendations for supplemental testing |

A) Please note: A non-reactive anti-HBc result can indicate that the patient is either susceptible to HBV infection due to no past exposure or is immune to HBV infection due to vaccination.

| Final Elecsys Anti-HBc II assay result | | | |
| --- | --- | --- | --- |
| Initial result (COI) | Result after retest (COI) | Final results | Interpretation of results |
| > 1.1 | No retest required | Non-reactive^{A)} | Antibodies to HBc were not detected; does not exclude the possibility of exposure to HBV |
| 1.1 ≥ COI > 0.9 | If 2 of the 3 results have a COI > 1.0 | Non-reactive | Antibodies to HBc were not detected; does not exclude the possibility of exposure to HBV |
| | If 2 of the 3 results have a COI ≤ 1.0 | Reactive | Presumptive evidence of antibodies to HBc.
Follow CDC recommendations for supplemental testing. |
| ≤ 0.9 | No retest required | Reactive | Presumptive evidence of antibodies to HBc.
Follow CDC recommendations for supplemental testing. |

A) Please note: A non-reactive anti-HBc result can indicate that the patient is either susceptible to HBV infection due to no past exposure or is immune to HBV infection due to vaccination.

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C Instrument Description Information:

1. Instrument Name:
cobas e immunoassay analyzer.

2. Specimen Identification:
Automated specimen identification using barcode scanning by the instrument.

3. Specimen Sampling and Handling:
Specimen sampling and handling is fully automated on the instrument.

4. Calibration:
Elecsys Anti-HBc II reagent components contain calibrators AHBC2 Cal1 and AHBC2 Cal2.
- AHBC 2 Cal1(negative): 1 bottle of 1.0 mL human serum; preservative
- AHBC 2 Cal2 (positive): 1 bottle of 1.0 mL, Anti HBc (human) > 8 WHO IU/mL in human serum; preservative

5. Quality Control:
The Elecsys Anti-HBc II assay uses PreciControl Anti-HBc II for quality control.
- PC A-HBCII 1 (negative): Each bottle contains 1.3 mL of human serum, negative for anti-HBc; buffered and preserved with 0.4% Bronidox L.
- PC A-HBCII 2 (positive): Each bottle contains 1.3 mL of control serum Anti-HBc antibodies (human) approximately 1 IU/mL (WHO units) in human serum; buffered with HEPES and preserved with 0.4% Bronidox L.

V Substantial Equivalence Information:

A Predicate Device Name(s):
Abbott ARCHITECT CORE

B Predicate 510(k) Number(s):
P080023

C Comparison with Predicate(s):

| Device & Predicate Device(s): | K260046 | P080023 |
| --- | --- | --- |
| Device Trade Name | Elecsys Anti-HBc II | Abbott ARCHITECT CORE |
| General Device | | |

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| Characteristic Similarities | | |
| --- | --- | --- |
| Regulation Number | 21 CFR 866.3173 | Same |
| Regulation Name | Hepatitis B virus antibody assays | Same |
| Regulatory Class | Class II | Class III |
| Product Code | SEI | Same |
| Intended Use | Immunoassay for the in vitro qualitative determination of total antibodies to hepatitis B core antigen (anti HBc) in human adult and pediatric (2 through 21 years of age) serum and plasma (lithium heparin, sodium citrate, potassium EDTA) in patients with the symptoms of hepatitis or who may be at risk for hepatitis B virus (HBV) infection. The detection of total anti HBc is indicative of a laboratory diagnosis for HBV infection. Further HBV serological marker testing is required to define the specific disease state. The immunoassay's performance has not been established for the monitoring of HBV disease or therapy.
The electrochemiluminescence immunoassay “ECLIA” is intended for use on the cobas e immunoassay analyzers. | The ARCHITECT CORE assay is a chemiluminescent microparticle immunoassay (CMIA) for the qualitative detection of IgG and IgM antibodies to hepatitis B core antigen (anti-HBc) in human adult and pediatric serum and plasma (dipotassium EDTA, lithium heparin, sodium heparin) and neonatal serum.
It is intended as an aid in the diagnosis of acute, chronic, or resolved hepatitis B virus (HBV) infection in conjunction with other laboratory results and clinical information. |
| Analyte Measured | Total anti-HBc antibodies | Same |
| General Device Characteristic Differences | | |
| Test Principle | Competition principle | Two-step immunoassay |
| Sample Type/Matrix | Serum and plasma (lithium heparin, sodium citrate, potassium EDTA) | Serum and plasma (dipotassium EDTA, lithium heparin, sodium heparin) |

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| Calibrator | AHBC2 Cal1
AHBC2 Cal2 | ARCHITECT CORE
Calibrators |
| --- | --- | --- |
| Controls | PreciControl Anti-HBc II | ARCHITECT CORE Controls |
| Instrument Platform | cobas e immunoassay
analyzers | ARCHITECT i System |

VI Standards/Guidance Documents Referenced:

CLSI EP05-A3: Clinical Laboratory Standards Institute. Evaluation of the Precision of Quantitative Measurement Procedures; Approved Guideline – Third Edition. CLSI Guideline EP05-A3, CLSI: Wayne, PA, 2014.

VII Performance Characteristics (if/when applicable):

A Analytical Performance:

1. Precision/Reproducibility: See P100031.
2. Linearity: Not applicable.
3. Analytical Specificity/Interference: See P100031.
4. Detection Limit and Assay Reportable Range: Not applicable.
5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods): See P100031.
6. Assay Cut-Off: See P100031.

B Comparison Studies:

1. Method Comparison with Predicate Device: Not Applicable. See Clinical Studies below.

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2. Matrix Comparison: See P100031.

# C Clinical Studies:

1. Clinical Sensitivity: Not Applicable.
2. Clinical Specificity: Not Applicable.
3. Clinical Cut-Off: Not Applicable.
4. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable)

Performance of Anti-HBc II on cobas e801 was evaluated against comparator/s by testing 119 prospectively collected serum specimens from pediatric participants aged 2 through 21 years, at risk for hepatitis B.

Table 1. Prospective pediatric study results for Elecsys Anti-HBc II

| Elecsys Anti-HBc II | Comparator Reactive [n] | Comparator Nonreactive [n] |
| --- | --- | --- |
| Reactive | 0 | 0 |
| Nonreactive | 0 | 119 |
| Total | 0 | 119 |

Table 2. Percent agreements with confidence intervals (CI)

| Age range (years) | PPA | | NPA | |
| --- | --- | --- | --- | --- |
| | % (n/N) | 95% CI | % (n/N) | 95% CI |
| 2-11 | NA (0/0) | NA | 100(38/38) | 90.6-100 |
| 12-21 | NA (0/0) | NA | 100(81/81) | 95.4-100 |
| Total | NA | NA | 100(119/119) | 96.9-100 |

Because no positive specimens were identified in the comparison study, a spiking study was conducted to evaluate the performance of the Elecsys Anti-HBc II assay in adult and pediatric samples. Thirty negative pediatric samples, with ages ranging from 2 through 21 years, were spiked with Anti-HBc human positive serum and compared to samples from a single pool of non-reactive adult serum ( $\geq 22$ years of age) that were spiked with the same volume of positive sample. The absolute differences between the 30 pediatric (spiked) and

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adult (spiked) samples ranged from 0.00103 to 0.0266 COI, with a mean absolute difference of 0.0107 COI. The results met the ≤ 0.20 COI acceptance criteria, supporting that the assay is suitable for the pediatric population.

D Expected Values/Reference Range:
See P100031

VIII Proposed Labeling:
The labeling supports the finding of substantial equivalence for this device.

IX Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

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