LIAISON EA IGG

K060204 · DiaSorin, Inc. · LSE · Oct 18, 2006 · Microbiology

Device Facts

• Record ID: K060204
• Device Name: LIAISON EA IGG
• Applicant: DiaSorin, Inc.
• Product Code: LSE · Microbiology
• Decision Date: Oct 18, 2006
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3235
• Device Class: Class 1
• Attributes: 3rd-Party Reviewed

Indications for Use

The LIAISON® EA IgG assay and LIAISON® EA IgG Controls use chemiluniescent immunoassay (CLIA) technology on the LIAISON Analyzer for the qualitative determination of IgG antibodies to Epstein-Barr virus early antigen-diffuse [EA(D)] in human serum. This assay can be used as an aid in the clinical laboratory diagnosis of Epstein-Barr viral Syndrome in patients with signs and symptoms of EBV infection such as infectious mononucleosis (IM).

Device Story

The LIAISON® EA IgG is an indirect chemiluminescence immunoassay (CLIA) performed on the LIAISON® Analyzer. It utilizes magnetic particles coated with 47-kDa recombinant EA(D) antigen and an isoluminol-antibody conjugate. Input: human serum samples. Process: samples are incubated with magnetic particles; EA(D) antibodies bind to the solid phase; isoluminol-antibody conjugate is added; unbound material is washed away; starter reagents induce a flash chemiluminescence reaction. Output: relative light units (RLU) measured by a photomultiplier, indicating the presence of EA(D) IgG antibodies. Used in clinical laboratories by trained personnel. Results assist clinicians in diagnosing Epstein-Barr viral syndrome in patients with symptoms like infectious mononucleosis. The device aids in patient management by providing serological evidence of EBV infection.

Clinical Evidence

Clinical performance was evaluated using 70 retrospective samples from acute EBV patients and 823 prospective samples from patients referred for EBV testing. In retrospective samples, the device showed 100% positive agreement (70/70) with reference serological profiles. In prospective samples, negative agreement was 98.4% (62/63) for seronegative subjects and 56.9% for past infection cases. Precision testing across three sites showed a mean total %CV of 11.2%. Cross-reactivity was evaluated against 222 samples; 11 samples (including CMV, VZV, HIV, and Hepatitis B) showed positive or equivocal results.

Technological Characteristics

Indirect chemiluminescence immunoassay (CLIA). Solid phase: magnetic microparticles coated with 47-kDa recombinant EA(D) polypeptide. Conjugate: mouse monoclonal anti-human IgG-isoluminol derivative. Energy source: electrical (LIAISON® Analyzer). Form factor: automated benchtop analyzer. Connectivity: standalone system. Software: embedded firmware for automated processing and signal quantification. Sterilization: N/A (reagents).

Indications for Use

Indicated for the qualitative determination of IgG antibodies to Epstein-Barr virus early antigen-diffuse [EA(D)] in human serum as an aid in the clinical laboratory diagnosis of Epstein-Barr viral Syndrome such as infectious mononucleosis (IM). Not for use in immunocompromised/immunosuppressed patients, cord blood, neonates, infants, or for diagnosis of nasopharyngeal carcinoma, Burkitt's lymphoma, or other EBV-associated lymphomas. Prescription use only.

Regulatory Classification

Identification

Epstein-Barr virus serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to Epstein-Barr virus in serum. The identification aids in the diagnosis of Epstein-Barr virus infections and provides epidemiological information on diseases caused by these viruses. Epstein-Barr viruses are thought to cause infectious mononucleosis and have been associated with Burkitt's lymphoma (a tumor of the jaw in African children and young adults) and postnasal carcinoma (cancer).

Predicate Devices

• DiaSorin ETI-EA-G Kit (K992191)

Submission Summary (Full Text)

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510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
DEVICE ONLY TEMPLATE

A. 510(k) Number:
K060204

B. Purpose for Submission:
New device clearance

C. Measurand:
IgG antibodies to Epstein-Barr Virus early antigen-diffuse EA(D)

D. Type of Test:
Qualitative, CLIA

E. Applicant:
DiaSorin Inc.

F. Proprietary and Established Names:
DiaSorin LIAISON® EA IgG assay

G. Regulatory Information:
a) Regulation section:
21 CFR Part 866.3235, Epstein-Barr Virus Serological Reagents.
b) Classification:
Class I
Product Code:
LSE
c) Panel:
83 Microbiology

H. Intended Use:
a) Intended use(s):
Qualitative detection of specific IgG antibodies to Epstein-Barr virus Early
Antigen Diffuse

b) Indication(s) for use:
The LIAISON® EA IgG assay uses chemiluminescent immunoassay (CLIA)
technology on the LIAISON® Analyzer for the qualitative determination of
IgG antibodies to Epstein-Barr virus early antigen-diffuse [EA(D)] in human
serum. This assay can be used as an aid in the clinical laboratory diagnosis of
Epstein-Barr viral Syndrome such as infectious mononucleosis (IM).

c) Special condition for use statement(s):
LIAISON® Control EA IgG kit is used in conjunction with LIAISON® EA
IgG immunoassay for monitoring substantial reagent failure.

The new device is not intended to be sold over the counter and is for
prescription use only. Warnings on applicant labeling state “Under United
States federal law restricts this device to sale by or on the order of a licensed
practitioner or physician”.

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Assay performance characteristics have not been established for immunocompromised or immunosuppressed patients, cord blood, neonatal or infant specimens. Assay performance characteristics have not been established for the diagnosis of nasopharyngeal carcinoma, Burkitt's lymphoma, and other EBV-associated lymphomas.

d) Special instrument Requirements:

Materials required but not provided with the device: LIAISON® EA IgG immunoassay is performed on the LIAISON® Chemiluminescence Analyzer (Model 15970), a fully automated system with continuous loading combining the Chemiluminescence technology with magnetic micro particles as solid phase. The Analyzer was originally cleared on February 12, 2004 (reference K032844).

Other accessories such as LIAISON Module, LIAISON Starter Kit, LIAISON Light Check, LIAISON Wash System Liquid, LIAISON Waste Bags, LIAISON Cleaning Kit are also required to perform the assay.

# I. Device Description:

Indirect chemiluminescence immunoassay

# J. Substantial Equivalence Information:

a) Predicate device name(s):

DiaSorin ETI-EA-G

b) Predicate K number(s):

K992191

Comparison with predicate:

| Characteristic | New Device | Predicate |
| --- | --- | --- |
| | Liaison® EA IgG | ETI-EA-G |
| Similarities | | |
| Intended Use | Qualitative detection of specific IgG antibodies to Epstein-Barr virus Early Antigen Diffuse | Qualitative and/or semi-quantitative detection of IgG antibodies to Epstein-Barr virus Early Antigen diffuse [EA(D)] |
| Indications for Use | Aid in the clinical laboratory diagnosis of Epstein-Barr Viral Syndrome in patients with signs and symptoms of EBV infection such as infectious mononucleosis. | Aid in the diagnosis of primary or reactivated infectious mononucleosis in adult and pediatric populations. |
| Antigens Used | Epstein-Barr early antigen-diffuse (47-kDa recombinant polypeptide) | Epstein-Barr virus early antigen-diffuse (47-kDa recombinant polypeptide) |
| Sample Matrix | Serum | Serum |
| Differences | | |
| Type of Assay | Antibody Capture | Enzyme Linked Immunosorbent |

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| Characteristic | New Device | Predicate |
| --- | --- | --- |
| | Liaison® EA IgG | ETI-EA-G |
| | Chemiluminescence Immunoassay (CLIA) | assay (ELISA) |
| Sample Handling/Processing | Automated | Manual |
| Detector | Mouse monoclonal antibodies to human IgG conjugated to isoluminol derivative | Goat anti-human IgG conjugated to horseradish peroxidase |
| Capture Reagent | Magnetic microparticles coated with EA(d) recombinant polypeptide | Microtiter wells coated with Epstein-Barr Early Antigen (D) antigen-(47-kDa recombinant polypeptide) |
| Controls | Two (negative and positive) | Three (negative, positive and low positive) |
| Reagent Storage | On-board or in refrigerator | Refrigerator only |
| Calibration | Two-point verification of stored 10-point master curve | Single point calibrator (Qualitative) or 4-point curve (semi-quantitative) |
| Equivocal Zone | Yes (± 10% about the cutoff) | No |
| Measurement System | Photomultiplier (flash chemiluminescence reader) | Spectrophotometer (ELISA Plate reader) |
| Total Incubation Time | 21 minutes | 150 minutes |
| Interference Testing | Bilirubin to 20 mg/dl | Bilirubin to 30 mg/dl |
| | Hemoglobin to 1000 mg/dl | Hemoglobin to 2500 mg/dl |
| | Triglycerides (Triolein) to 3000 mg/dl | Triglycerides to 1000 mg/dl |
| | | Cholesterol 10 1000 mg/dl |

# K. Standard/Guidance Document Referenced (if applicable):

# L. Test Principle:

The method for the qualitative determination of specific IgG to EBV viral antigens early antigen-diffuse [EA(D)] recombinant polypeptide as an indirect chemiluminescence immunoassay (CLIA). The principal components of the test are magnetic particles (solid phase) coated with EBV synthetic peptides and a conjugate of mouse monoclonal antibody to human IgG or linked to an isoluminol derivative (isoluminol-antibody conjugate). During the first incubation, EA(D) antibodies present in calibrators, samples or controls bind to the solid phase. During the second incubation, the antibody conjugate reacts with EBV IgG antibodies that are already bound to the solid phase. After each incubation, unbound material is removed with a wash cycle. Subsequently, the starter reagents are added and a flash chemiluminescence reaction is thus induced. The light signal, and hence the amount of isoluminol-antibody conjugate, is measured by a

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photomultiplier results expressed as U/ml and is indicative of the presence of EBV EA(D) IgG antibodies present in calibrators, samples or controls.

## M. Performance Characteristics (if/when applicable):

### 1. Analytical performance:

#### a. Precision/Reproducibility:

This study was conducted at three external US laboratories and at the applicant address (Stillwater, MN). A nine-member serum coded panel was prepared at DiaSorin, Italy and provided to each site for testing by the applicant device (LIAISON® EA IgG assay). Seven of the nine samples were selected or prepared so as to exhibit a low- to mid-positive Analyte level (i.e. samples demonstrating an expected analyte level approximately two to five times the cutoff). All panel members were divided into aliquots and stored frozen prior to testing. Samples EAS1-3 were tested at sites #1, #3, and #5, while EA1-6 were tested at sites #2, #3, and #5. The same coded panel was tested at all three sites, in three replicates per run for ten runs. LIAISON® EA IgG results were expressed in U/ml. The mean, standard deviation, and coefficient of variation (%CV) of the results were computed by the total and different components of variability for each of the tested specimens for each of the sites and across sites.. The results are summarized in the following tables.

LIAISON® EA IgG

| | mean | | within run | within run | between run | between run | between site | between site | total | total |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| ID# | N | U/ml | StD | %CV | StD | %CV | StD | %CV | StD | %CV |
| EAS1 | 90 | 47.6 | 1.78 | 3.71 | 4.56 | 8.65 | 2.46 | 5.16 | 4.78 | 10.04 |
| EAS2 | 90 | 99.1 | 6.10 | 6.06 | 9.24 | 8.60 | 4.64 | 4.68 | 10.82 | 10.92 |
| EAS3 | 90 | 112.3 | 7.50 | 7.07 | 15.81 | 13.19 | 2.84 | 2.53 | 17.26 | 15.36 |
| EA1 | 90 | 18.2 | 0.93 | 5.17 | 1.56 | 5.50 | 1.37 | 7.52 | 1.85 | 10.15 |
| EA2 | 90 | 20.4 | 0.63 | 3.17 | 2.27 | 5.87 | 2.31 | 11.33 | 2.34 | 11.45 |
| EA3 | 90 | 47.4 | 2.07 | 4.60 | 4.87 | 5.18 | 5.09 | 10.75 | 5.28 | 11.15 |
| EA4 | 90 | 35.9 | 1.58 | 4.60 | 4.02 | 6.02 | 4.08 | 11.35 | 4.30 | 11.99 |
| EA5 | 90 | 52.4 | 2.03 | 3.88 | 4.54 | 3.55 | 5.01 | 9.56 | 4.94 | 9.43 |
| EA6 | 90 | 18.1 | 0.60 | 3.38 | 1.72 | 4.12 | 1.86 | 10.27 | 1.80 | 9.91 |

The total observed precision (%CV) for the LIAISON® EA IgG assay for low- to high-positive serum samples ranged from 9.4% to 15.4% with a mean of 11.2%. The predicate device, DiaSorin ETI-EA-G ELISA, reported total %CVs ranging from 6.6% to 15.9% for similar samples with a mean of 10.2%. The two assays are relatively equivalent.

#### b. Linearity/assay reportable range: NA

#### c. Traceability, Stability, Expected values (controls, calibrators, or method):

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Controls are provided specifically designed for use in conjunction with the performance of the assay, for more information see the section regarding matrix comparison below.

# d. Detection limit:

See assay cut-off below

# e. Analytical specificity:

The cross-reactivity studies for the LIAISON® EA IgG assay were designed to evaluate potential interference from IgG immunoglobulins directed against closely-related members of the herpes virus family (e.g. HSV-1, HSV-2, VZV, CMV), from other organisms that may cause symptoms similar to EBV (Toxoplasma gondii, rubella virus) and from other conditions that may result from atypical immune system activity (rheumatoid factor (RF)). Samples for these studies were selected using commercially available devices.

| Organism / condition | Number of Samples | Positive or Equivocal LIAISON® EA IgG Result |
| --- | --- | --- |
| EBV VCA IgG | 21 | 0/21 |
| EBV VCA IgG/EBNA IgG | 25 | 1/25 |
| CMV IgG | 25 | 2/25 |
| VZV IgG | 22 | 1/22 |
| HSV-1 IgG | 23 | 0/23 |
| HSV-2 IgG | 21 | 3/21 |
| Toxoplasma gondii IgG | 20 | 2/20 |
| Rubella virus IgG | 24 | 0/24 |
| Hepatitis B virus (anti-HBs) | 15 | 1/15 |
| HIV | 11 | 2/11 |
| RF | 2 | 0/2 |
| ANA | 8 | 0/8 |
| HAMA | 5 | 0/5 |
| Total | 222 | 11/222 |

Eleven specimens out of 222 total specimens tested from the cross-reaction panel returned positive or equivocal results in the LIAISON® EA IgG assay. Seven of the eleven discordant samples were equivocal by LIAISON® EA IgG. Equivocal results by LIAISON® EA IgG are included in the calculations of non-agreement since it was not possible to acquire follow-up samples collected one to two weeks later as recommended.

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f. Assay cut-off:

The cutoff for the LIAISON® EA IgG assay was determined during European clinical trials in which 519 samples were run at two different sites. The samples consisted of either single samples or serial panel from different selected populations (subjects never infected by EBV, patients affected by primary EBV infection, subjects with past EBV infection, patients with suspected EBV reactivation and transplant recipients). The samples were tested in parallel with the LIAISON® EA IgG assay and a commercially available ELISA assay as the comparison method. Consensus with the serological data such as the combined EBV patients was applied to define the expected results: 208 samples were expected to be EA IgG positive and 291 samples were expected to be EA IgG negative, while 20 specimens were equivocal either by the comparison method or the original classification and therefore were not included in the data analysis.

The analysis of the data determined that the best sensitivity and specificity balance was obtained using a cutoff at 10 U/ml. Therefore, in the LIAISON® EA IgG assay, a sample is defined as positive if the level is equal or greater than 10 U/ml, and defined as negative of the level is lower than 10 U/ml.

The selected cutoff was validated in the US clinical trials. To account for observed assay imprecision, an equivocal zone was established about the cutoff. A nominal equivocal zone of ± 10% (dose) was assigned to this assay (for more detail on the establishment of this zone, see the response to question 4 on page 2 of 13 within the second deficiency response). Typical total imprecision (%CV) across the range of the assay is approximately 10%. Based upon the observed separation of the infected and non-infected patient responses, it is not likely that a significant percentage of samples will be affected by the equivocal zone. A total of 70 selected archive samples and 823 unselected prospectively collected samples were tested in the US trials. The resulting data clearly indicated separation for positive and negative results provided by the selected cutoff.

2. Comparison studies:

a. Method comparison with predicate device:

DiaSorin LIAISON® EA IgG assays were compared to the DiaSorin ETI-EA-G assays.

b. Matrix comparison:

3. Clinical studies:

a. Clinical sensitivity:

See Performance Characteristics below

b. Clinical specificity:

See Performance Characteristics below

c. Other clinical supportive data (when a and b are not applicable):

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# Clinical Studies

The objective was to obtain sufficient data from a well-controlled clinical trial to support the intended use statement and product claims. Specific objectives were:

i. Evaluate the substantial equivalence of the LIAISON® EA IgG assay to an FDA cleared method (DiaSorin ETI-EA-G; K992191).
ii. Describe the ability of the LIAISON® EA IgG assay to discriminate between samples from subjects not previously infected by EBV and those that have had either previous or current contact with EBV.
iii. Verify the precision of the assay using coded panels supplied by the DiaSorin.
iv. Verify the quality control procedures of the assay using the LIAISON® EA IgG Control Sera.

Four external US laboratories and DiaSorin, Stillwater, MN performed testing. The testing was conducted on retrospective and prospective samples that were collected and tested as described in the following table.

| | SITE #1, #2, and #5 | SITE #3 | SITE #4 |
| --- | --- | --- | --- |
| Type of Samples Tested | Coded Reproducibility Panel | US Prospective Samples (460) Repository Samples with serological data Coded Reproducibility Panel | US Prospective Samples (363) |
| Population | N/A | Individuals sent to the lab for EBV testing EBV IgM reactive patients | Individuals sent to the lab for heterophile antibody or VCA IgM testing |
| # Samples Tested | N/A | 530 | 363 |
| Comparison Assay | N/A | DiaSorin ETI-EA-G (ELISA) | DiaSorin ETI-EA-G (ELISA) |
| Notes | N/A | A reference laboratory prospectively collected the EBV routine samples and supplied the relevant data. The samples were tested at Site #3. | A reference laboratory prospectively collected the EBV routine samples and supplied the relevant data. The samples were tested at Site #4. |

The samples were tested with the LIAISON® EA IgG and the comparison assay at the trail sites, per manufacturers instruction for use. The technicians performing the testing were blinded to the samples' previous results. The resulting data was sent to the clinical site monitor for analysis by DiaSorin.

Study Population: Testing was performed on repository and prospective samples as follows:

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i. 460 residual specimens prospectively collected from non-selected subjects that were sent to the laboratory for EBV testing. These were excess serum drawn from patients for whom EBV testing was requested, with sufficient volume to perform all testing required. Collection followed an IRB-approved protocol, with a waiver of informed consent, as there was no link to patient identity. The samples were stored frozen at $-20^{\circ}\mathrm{C}$ prior to testing.

ii. 363 residual specimens prospectively collected from non-selected subjects that were sent to the laboratory for heterophile antibody (Monospot) of VCA IgM Testing. These were excess serum drawn from patients for whom EBV testing was requested, with sufficient volume to perform all testing required. Collection followed an IRB-approved protocol, with a waiver of informed consent, as there was no link to patient identity. The samples were stored frozen at $-20^{\circ}\mathrm{C}$ prior to testing.

iii. 70 single samples from patients with serologic results suggesting an acute EBV infection. The sample selection was based on a specific EBV serological profile: VCA IgG positive, VCA IgM positive.

Study Analysis: LIAISON® EA IgG results were expressed in U/ml. Samples returning values $< 9.0$ U/ml were classified as negative, samples between 9.0 and $10.9$ U/ml as equivocal and those greater than $\geq 11.0$ U/ml as positive. The DiaSorin ETI-EA-G kit is an indirect enzyme-linked immunosorbent assay in which the results were expressed in AU and the threshold for negative samples is 20 AU. There is no equivocal zone in the predicate device. The performance of the LIAISON® EA IgG assay was determined by the percent agreement amount negative samples, percent agreement among positive samples, and overall percent agreement with the reference method in specific populations. The relevant $95\%$ confidence limits were computed by applying the extract method. Results are detailed below:

**Retrospective Samples:** 70 frozen archived (retrospective) single samples with a serological pattern consistent with acute EBV infection (based on IgG and IgM anti-VCA positive). The group was $50\%$ female. Approximately $31\%$ (22) were below 18 years of age and the other $69\%$ (48) ranged between 19 and 42 years of age. Comparison is identified below.

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| | VCA IgG | VCA IgM | EBNA-1 IgG | Total |
| --- | --- | --- | --- | --- |
| EBV seronegative | - | - | - | 0 |
| Primary infection | + | + | - | 9 |
| Convalescen t | + | + | + | 61 |
| Past infection | + | - | + | 0 |
| Indeterminate | | | | 0 |
| VCA IgG only | + | - | - | 0 |
| VCA IgM only | - | + | - | 0 |
| EBNA IgG only | - | - | + | 0 |
| All | | | | 70 |

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Based on these serological classifications, the LIAISON® EA IgG results for the retrospective samples were compared with those obtained with the reference assays.

Positive % Agreement $95\%$ CI

| Primary Infection | 100.0% (9/9) | 21.2-100% |
| --- | --- | --- |
| Convalescent | 100% (61/61) | 95.2-100% |
| Total Positive Agreement | 100% (70/70) | 86.0 – 100.0% |

Prospective Samples: Using the results for the prospective samples in three reference assays (VCA IgG, EBNA-1 IgG, VCA IgM ELISA), the samples were grouped into serological categories. "Indeterminate" refers to serological patterns that are not consistent with the typical EBV categories; EBV seronegative, acute or past infection. The profiles and number of occurrences are presented in the following table.

Using the results for the prospective samples in three reference assays (VCA IgG, EBNA-1 IgG and VCA IgM ELISA), the samples were grouped into serological categories. The profiles and number of occurrences are presented in the following table:

Prospective samples: Subjects Sent to the Laboratory for EBV Testing

| | | VCA IgG | | VCA IgM | | EBNA-1 IgG | Total |
| --- | --- | --- | --- | --- | --- | --- | --- |
| EBV seronegative | | - | | - | | - | 63 |
| Primary infection | | + | | + | | - | 29 |
| Past infection | | + | | - | | + | 576 |
| Indeterminate | | | | | | | 82 |
| | | | | | | | 67 |
| | n | VCA IgG | VCA IgM | EBNA-1 IgG | LIAISON® EA IgG | | 5 |
| | | | | | Pos | Neg | Eov |
| EBV seronegative | 63 | - | - | - | 1 | 62 | |
| Primary infection | 29 | + | + | - | 25 | 3 | 1 |
| Convalescent | 73 | + | + | + | 44 | 26 | 3 |
| Past infection | 576 | + | - | + | 224 | 328 | 24 |
| Indeterminate* | | | | | | | |
| VCA IgG only | 67 | + | - | - | 21 | 45 | 1 |
| VCA IgM only | 5 | - | + | - | 1 | 4 | |
| EBNA IgG only | 10 | - | - | + | 1 | 9 | |
| Total | 823 | | | | 317 | 477 | 29 |

results for the ith the

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| | n | VCA IgG | VCA IgM | EBNA-1 IgG | LIAISON® EA IgG | | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| | | | | | Pos | Neg | Eqv |
| EBV seronegative | 63 | – | – | – | 1 | 62 | |
| Primary infection | 29 | + | + | – | 25 | 3 | 1 |
| Convalescent | 73 | + | + | + | 44 | 26 | 3 |
| Past infection | 576 | + | – | + | 224 | 328 | 24 |
| Indeterminate* | | | | | | | |
| VCA IgG only | 67 | + | – | – | 21 | 45 | 1 |
| VCA IgM only | 5 | – | + | – | 1 | 4 | |
| EBNA IgG only | 10 | – | – | + | 1 | 9 | |
| Total | 823 | | | | 317 | 477 | 29 |

95% Confidence Levels based on the above serological classifications are as follows:

| EBV seronegative | Agreement | 95% CI |
| --- | --- | --- |
| Negative Agreement | 62/63 = 98.4% | 95.1 – 100% |
| Primary Infection | | |
| Positive Agreement | 25/29 = 86.2% | 71.2 – 95.2% |
| Convalescent* | | |
| Positive Agreement | 44/73 = 60.3% | 49.9 – 69.9% |
| Past Infection | | |
| Negative Agreement | 328/576 = 56.9% | 53.4 – 60.4% |
| Indeterminate** | | |
| Positive Agreement | 22/25 = 88% | 71.8 – 96.6% |
| Negative Agreement | 56/57 = 98.2% | 95.0 – 99.9% |

* Early Antigen antibodies may or may not be present in convalescence.
** Indeterminate Positive and Negative agreements were established based on a comparison to a Reference EA(d) IgG
ELISA assay and include VCA IgG only, VCA IgM only and EBNA IgG only samples as indicated above.

4. Clinical cut-off:
See assay cut-off previously described in this document

5. Expected values/Reference range:
The LIAISON® EA IgG assay was tested with prospectively collected samples from subjects sent to the laboratory for EBV testing (n=823) to evaluate the prevalence of IgG antibodies to EA(D) in these populations. The subjects sent to the laboratory for EBV testing were 61.7% female (508), 28.1% male (231) and 10.2% unknown (84) and represented the mid-Atlantic and Northeastern US.

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The distribution of results for IgG antibodies to EA(D) in this population as determined by the LIAISON® EA IgG Assay is summarized in the following table.

| | N | Negative | Equivocal | Positive | Prevalence |
| --- | --- | --- | --- | --- | --- |
| Total | 823 | 477 | 29 | 317 | 38.5% |
| Gender | | | | | |
| Female | 508 | 288 | 19 | 201 | 39.6% |
| Male | 231 | 137 | 7 | 87 | 37.7% |
| Unknown | 84 | 52 | 3 | 29 | 34.5% |
| Age (years) | | | | | |
| ≤ 18 | 173 | 114 | 8 | 51 | 29.5% |
| <10 | 29 | 20 | 1 | 8 | 27.6% |
| 10 – 19 | 183 | 119 | 8 | 56 | 30.6% |
| 20 – 29 | 190 | 117 | 7 | 66 | 34.7% |
| 30 – 39 | 95 | 55 | 1 | 39 | 41.1% |
| 40 – 49 | 78 | 32 | 3 | 43 | 45.3% |
| 50 – 59 | 59 | 30 | 4 | 25 | 42.4% |
| 60 – 69 | 32 | 14 | 1 | 17 | 53.1% |
| ≥ 70 | 27 | 17 | 0 | 10 | 37.0% |
| Unknown | 130 | 73 | 4 | 53 | 40.8% |

# N. Proposed labeling:

The labeling is sufficient and it satisfies the requirement of 21 CFR Part 809.10.

# WARNINGS and PRECAUTIONS:

1. For in vitro diagnostic use.
2. The human blood source material used to produce the components provided in this kit is derived from donations found to be non-reactive for HBsAg, antibodies to HCV, HIV-1 and HIV-2 when tested by an FDA-approved method and found to be non-reactive for syphilis when tested by a serological test. Because no test method can offer complete assurance that laboratory specimens are pathogen-free, specimens should be handled at the Biosafety Level 2 as recommended for any potentially infectious human serum or blood specimen in the CDC-NIH manual, Biosafety in Microbiological and Biomedical Laboratories, 4th Edition, May 1999, and CLSI Approved Guideline M29-A, Protection of Laboratory Workers from Instrument Biohazards and Infectious Disease Transmitted by Blood, Body Fluids, and Tissue (9, 10, 11).
3. Some reagents contain sodium azide as a preservative. Because sodium azide may form explosive lead or copper azide in plumbing, it is recommended that drains be thoroughly flushed with water after disposal of solutions containing sodium azide.
4. Do not eat, drink, smoke or apply cosmetics in the assay laboratory.

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5. Do not pipette solutions by mouth.
6. Avoid direct contact with all potentially infectious materials by using protective clothing such as lab coats, protective glasses and disposable gloves. Wash hands thoroughly at the end of each assay.
7. Avoid splashing or forming an aerosol. Any reagent spills should be washed with a 5% sodium hypochlorite solution and disposed of as though potentially infectious.
8. All samples, biological reagents and materials used in the assay must be considered potentially able to transmit infectious agents. They should therefore be disposed of in accordance with the prevailing regulations and guidelines of the agencies holding jurisdiction over the laboratory, and the regulations of each Country. Disposable materials must be incinerated; liquid waste must be decontaminated with sodium hypochlorite at a final concentration of 5% for at least 30 minutes. Any materials to be reused must be autoclaved using an overkill approach (USP 24, 2000, p. 2143). A minimum of one hour at 121°C is usually considered adequate, though the users must check the effectiveness of their decontamination cycle by initially validating it and routinely using biological indicators.
9. Specimens with elevated lipids (3000 mg/dL) may give erroneous results.
10. Assay interference due to circulating antibodies against Hepatitis A and Hepatitis C viruses has not been evaluated. The user is responsible for establishing cross-reactivity performance with these infectious agents.
11. Assay cross-reactivity has been noted with some specimens containing antibody to Human Immunodeficiency Virus (HIV). Reactive results must contain a caution statement regarding possible cross-reactivity with HIV. HIV disease must be excluded before confirmation of diagnosis.

O. Conclusion:

The submitted material in this premarket notification is complete and supports a substantial equivalence decision.