HSV-2 ELISA IGG, MODEL EL0920G

K993724 · Mrl Diagnostics · MYF · Feb 1, 2000 · Microbiology

Device Facts

• Record ID: K993724
• Device Name: HSV-2 ELISA IGG, MODEL EL0920G
• Applicant: Mrl Diagnostics
• Product Code: MYF · Microbiology
• Decision Date: Feb 1, 2000
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3305
• Device Class: Class 2

Intended Use

MRL Diagnostics' HSV-2 ELISA IgG test is intended for qualitatively detecting the presence or absence of human IgG class antibodies to HSV-2 in human sera. In conjunction with the MRL HSV-1 ELISA IgG, the test is indicated for testing sexually active adults or expectant mothers for aiding in the presumptive diagnosis of HSV infection. The predictive value of a positive or negative result depends on the population's prevalence and the pretest likelihood of HSV-2 infection. The performance of this assay has not been established for use in a pediatric population, for neonatal screening, for testing of immunocompromised patients, or for use with automated equipment.

Device Story

The MRL Diagnostics HSV-2 ELISA IgG is an in vitro diagnostic assay for qualitative detection of human IgG antibodies to HSV-2 in serum. The device uses polystyrene microwells coated with recombinant gG-2 antigen. Patient serum and controls are incubated in wells; specific IgG antibodies bind to the antigen. After washing, peroxidase-conjugated anti-human IgG is added, followed by enzyme substrate and chromogen. The resulting color change is measured via spectrophotometric optical density (OD). The operator compares sample OD readings against reference cut-off ODs to determine results. The test is performed in a laboratory setting by trained personnel. Results aid clinicians in the presumptive diagnosis of HSV infection when used alongside MRL HSV-1 ELISA IgG. The device does not support automated equipment; it is a manual ELISA procedure.

Clinical Evidence

Clinical performance evaluated using masked, archived sera from sexually active adults (n=246) and expectant mothers (n=241). Sensitivity relative to Western blot was 96.1% (adults) and 100% (mothers); specificity was 97.0% (adults) and 96.1% (mothers). Sensitivity relative to culture (n=63) was 96.8%. CDC panel (n=not specified) showed 100% agreement. Cross-reactivity tested against CMV, EBV, HHV6, and VZV showed 90.9% total agreement. Reproducibility assessed via intra-assay, inter-assay, inter-lot, and inter-laboratory studies.

Technological Characteristics

ELISA-based serological assay. Components: polystyrene microwells coated with recombinant gG-2 antigen, peroxidase-conjugated anti-human IgG, enzyme substrate, chromogen, and stop reagent. Detection principle: spectrophotometric measurement of optical density (OD). Manual procedure; not for use with automated equipment.

Indications for Use

Indicated for sexually active adults and expectant mothers to aid in the presumptive diagnosis of HSV-2 infection by detecting human IgG class antibodies in serum. Not for pediatric use, neonatal screening, immunocompromised patients, or use with automated equipment.

Regulatory Classification

Identification

Herpes simplex virus serological assays are devices that consist of antigens and antisera used in various serological tests to identify antibodies to herpes simplex virus in serum. Additionally, some of the assays consist of herpes simplex virus antisera conjugated with a fluorescent dye (immunofluorescent assays) used to identify herpes simplex virus directly from clinical specimens or tissue culture isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by herpes simplex viruses and provides epidemiological information on these diseases. Herpes simplex viral infections range from common and mild lesions of the skin and mucous membranes to a severe form of encephalitis (inflammation of the brain). Neonatal herpes virus infections range from a mild infection to a severe generalized disease with a fatal outcome.

Special Controls

*Classification.* Class II (special controls). The device is classified as class II (special controls). The special control for the device is FDA's revised guidance document entitled “Class II Special Controls Guidance Document: Herpes Simplex Virus Types 1 and 2 Serological Assays.” For availability of the guidance revised document, see § 866.1(e).

Predicate Devices

• HSV-2 ELISA Test System, Zeus Scientific, Inc.
• HSV-2 Western Blot, University of Washington
• HSV-2 Culture, University of Washington

Submission Summary (Full Text)

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# K993724

### MRL Diagnostics HSV-2 ELISA IgG Catalog No. EL0920G

## 510(k) Summary of Safety and Effectiveness (K) Samed January 10, 2000 (Page 1 of 6)

| Applicant | MRL Diagnostics<br>a Focus/MRL Inc. Company<br>10703 Progress Way<br>Cypress, California 90630 |
|----------------------------------|------------------------------------------------------------------------------------------------|
| Establishment<br>Registration No | 2023365 |
| Contact Person | Michael J. Wagner, Esq. |
| Phone | [phone] |
| Telefax | [phone] |
| E-mail | [e-mail] |
| Summary Date | January 10, 2000 |
| Device Name | HSV-2 ELISA IgG |
| Classification | Herpes Simplex Virus Serological Reagents |
| | 21 CFR §866.3305 |
| | Class III |
| Predicate | 1) HSV-2 ELISA Test System, Zeus Scientific, Inc. |
| Device | 2) HSV-2 Western Blot, University of Washington |
| | 3) HSV-2 Culture, University of Washington |

800 445-0185

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In the MRL Diagnostics HSV-2 ELISA IgG assay, the polystyrene microwells are coated Device Description with recombinant gG-2 antigen. Diluted serum samples and controls are incubated in the wells to allow specific antibody present in the samples to react with the antigen. Nonspecific reactants are removed by washing, and peroxidase-conjugated anti-human IgG is added and reacts with specific IgG. Excess conjugate is removed by washing. Enzyme substrate and chromogen are added, and the color is allowed to develop. After adding the Stop Reagent, the resultant color change is quantified by a spectrophotometric reading of optical density (OD). Sample optical density readings are compared with reference cut-off OD readings to determine results.

- MRL Diagnostics' HSV-2 ELISA IgG test is intended for qualitatively detecting the Intended Use presence or absence of human IgG class antibodies to HSV-2 in human sera. In conjunction with the MRL HSV-1 ELISA IgG, the test is indicated for testing sexually active adults or expectant mothers for aiding in the presumptive diagnosis of HSV infection. The predictive value of a positive or negative result depends on the population's prevalence and the pretest likelihood of HSV-2 infection. The performance of this assay has not been established for use in a pediatric population, for neonatal screening, for testing of immunocompromised patients, or for use with automated equipment.

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An outside investigator assessed the device with masked, archived and unselected sera Expected Values from 1) sexually active adults over the age of 14 (n = 246), and 2) from expectant mothers (n = 241). The reference method was a HSV-2 Western blot from a Pacific Northwest university. The observed prevalences and the hypothetical predictive values for the two populations are shown in the tables below. The positive value will decrease proportionally to the prevalence of HSV infection as reflected in the table below. The calculations are based on MRL HSV-2 ELISA IgG having 1) a hypothetical sensitivity of 96.1% & a hypothetical specificity of 97.0% (sexually active adults), and 2) a hypothetical sensitivity of 100% and a hypothetical specificity of 96.1% (expectant mothers).

| Observed Prevalence with Sexually Active Adults & Expectant Mothers<br>all for the contract of the contribution of the comments of the comments of the comments of the comments of the comments of the comments of the comments of the comments of th | | | |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|
| Population | HSV-2 | Observed Prevalence<br>Comments of the contract and consisted on and consisted for any and the control of the control of the control of the control of the contribution of the contribution of the co | |
| Population | HSV-2<br>Sero-status | Observed Prevalence | |
| | | WB | MRL ELISA |
| Sexually Active Adults * | neg | 68.5% | 67.2% |
| | + | 31.5% | 32.4% |
| Expectant Mothers † | neg | 75.6% | 72.3% |
| | + | 24.4% | 27.3% |

* Excludes 5 atypical Western blots and 1 ELISA equivocal. + Excludes 3 atypical Western blots and 1 ELISA equivocal.

| Prevalence | Sexually Active Adults | | Expectant Mothers | |
|------------|------------------------|-------|-------------------|-------|
| | PPV | NPV | PPV | NPV |
| 50% | 97.0% | 97.0% | 96.2% | 96.1% |
| 40% | 95.5% | 98.0% | 94.5% | 97.4% |
| 30% | 93.2% | 98.7% | 91.7% | 98.3% |
| 25% | 91.4% | 99.0% | 89.5% | 98.7% |
| 20% | 88.9% | 99.2% | 86.5% | 99.0% |
| 15% | 85.0% | 99.5% | 81.9% | 99.3% |
| 10% | 78.1% | 99.7% | 74.0% | 99.6% |
| 5% | 62.8% | 99.8% | 57.4% | 99.8% |

### Prevalence vs. Hypothetical Predictive Values

Note: Sexually active adult and expectant mother populations in different geographic areas may produce different frequency distributions from the table above. Each laboratory should establish frequency distributions for their specific patient populations.

800 445-0185

714 220-1900

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| Relative | An outside investigator assessed the device's relative sensitivity and relative specificity |
|------------------|---------------------------------------------------------------------------------------------|
| Sensitivity and | with sera from expectant mothers (n = 241). The sera were sequentially submitted to the |
| Relative | laboratory, archived, and masked. The reference method was a HSV-2 Western blot |
| Specificity with | (WB) from a Pacific Northwest university. Of 3 atypical WBs, ELISA was 1 equivocal and |
| Expectant | 2 negatives. Of 58 WB positives, ELISA was 58 positive. Of 180 WB negatives, ELISA was |
| Mothers | 172 negatives, 7 positives, and 1 equivocal. |

### Relative Sensitivity and Relative Specificity with Expectant Mothers (n = 241)

| Characteristic | % (EL/WB)* | 95% CI |
|--------------------------------------|-----------------|------------|
| Sensitivity relative to Western blot | 100% (58/58) | 93.8-100% |
| Specificity relative to Western blot | 96.1% (172/179) | 92.1-98.4% |

* Excludes three atypical Western blots and one ELISA equivocal

An outside investigator assessed the device's relative sensitivity and relative specificity Relative with sera from sexually active adults over the age of 14 (n = 246). The sera were Sensitivity and sequentially submitted to the laboratory, archived, and masked. The reference method Relative was a HSV-2 Western blot from a Pacific Northwest university. Of 5 atypical WBs, Specificity with ELISA was 2 equivocal, 2 negative and 1 positive. Of 76 WB positives, ELISA was 73 Sexually Active positive and 3 negative. Of 165 WB negatives, ELISA was 159 negative, 5 positive, and 1 Adults equivocal.

Relative Sensitivity and Relative Specificity with Sexually Active Adults (n = 246)

| Characteristic | % (EL/WB)* | 95% CI |
|--------------------------------------|-----------------|------------|
| Sensitivity relative to Western blot | 96.1% (73/76) | 88.9-99.2% |
| Specificity relative to Western blot | 97.0% (159/164) | 93.0-99.0% |

* Excludes five atypical Western blots and one ELISA equivocal

Relative An outside investigator assessed the device's relative sensitivity using sera from culture positive patients (n = 63). Reference methods included culture (infection) and a HSV-2 Sensitivity with Culture Western blot (antibody) from a Pacific Northwest university. Of 5 atypical WBs, ELISA was 2 equivocal, 2 negative and 1 positive. Of 63 culture positives, ELISA was 61 positive Positives and 2 negative, and WB was 62 positive and 1 negative. Of 62 WB positives, ELISA was 61 positive and 1 negative.

| Relative Sensitivity with Culture Positives (n = 63) | | | |
|------------------------------------------------------|--|--|--|
| | | | |

| Relative Sensitivity with Culture Positives (n = 63) | | |
|------------------------------------------------------|----------------------|------------|
| Characteristic | % (EL/WB or Culture) | 95% CI |
| Sensitivity relative to culture | 96.8% (61/63)* | 89.0-99.6% |
| Sensitivity relative to Western blot | 98.4% (61/62)* | 91.3-100% |

*Of the 2 ELISA negatives, one was WB positive and the other WB negative.

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## K993724

| MRL Diagnostics | 11/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / |
|---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| HSV-2 ELISA IgG | 510(k) Summary of Safety and Effectiveness |
| Catalog No. EL0920G | Prepared January 10, 2000 (Page 5 of 6)<br>A Comments of the Comments of Children of Children Comments of Children Comments of Children<br>A Land Land Land Concession Company Comments of Children Comments of Children Comments of |

### The following information is from a serum panel obtained from the CDC and tested by Agreement with MRL Diagnostics. The results are presented as a means to convey further information on CDC Panel the performance of this assay with a masked, characterized serum panel. This does not the performance of the assay by the CDC. The panel consists of 37% positive and 63% negative samples. The MRL Diagnostics HSV-2 ELISA IgG demonstrated 100% total agreement with the CDC results. Of the results obtained by MRL Diagnostics, there was 100% agreement with the positive specimens and 100% agreement with the negative specimens.

An outside investigator assessed the device's relative specificity using sera from a Relative population of college students claiming to lack sexual experience (n = 81), and having a Specificity with published HSV-2 antibody prevalence of 2% (4/186).† The laboratory reference method a Low was a HSV-2 Western blot from a Pacific Northwest university. One atypical WB was an Prevalence ELISA negative. Of 78 WB negatives, ELISA was 77 negative and 1 positive. Of 2 WB Population negatives, ELISA was 2 positive.

Relative Specificity with a Low Prevalence Population (n = 81)

| Characteristic | % (EL/WB)* | 95% CI |
|--------------------------------------|---------------|-----------|
| Specificity relative to Western blot | 98.7% (77/78) | 93.1-100% |
| Sensitivity relative to Western blot | 100% (2/2) | 15.8-100% |

* Excludes one atypical Western blot.

+ Corey, L., A. Wald, New Developments in the Biology of Genital Herpes, in Clinical Management of Herpes Viruses, p.46.

An outside investigator assessed the device's type specificity using HSV-1 Western blot Type Specificity positive and HSV-2 Western Blot negative sera from the above described populations (n = with HSV-1 287): expectant mothers, sexually active adults, low prevalence persons, and HSV-1 Western Blot culture positives. Of 287 HSV-1 WB positive and HSV-2 WB negative samples, ELISA Positives was 276 negatives, 1 equivocal and 10 positives.

| Type Specificity with HSV-1 Western Blot Positives (n = 287) | | |
|--------------------------------------------------------------|-----------------|------------|
| Characteristic | % (EL/WB)* | 95% CI |
| Type-specificity relative to Western blot | 96.5% (276/286) | 93.7-98.3% |
| Type cross-reactivity relative to Western blot | 3.5% (10/286) | 1.7-6.3% |
| * Excludes equivocal ELISA result | | |

ecificity with HSV-1 Western Blot Positives (n = 287)

* Excludes one equivocal ELISA result.

MRL assessed the device's cross-reactivity using sera (n = 27) from 1) HSV sero-negative Cross-reactivity by another manufacturer's FDA cleared HSV ELISAs, and 2) IFA IgG positive for with taxonomically similar viruses including CMV, EBV VCA, HHV6 and VZV. Discrepants Taxonomically between the FDA cleared HSV ELISAs and the MRL device were analyzed using a type Related Viruses specific Western blot from a major university located in the Northwestern United States.

| Cross-reactivity with Taxonomically Related Viruses (n = 27)<br>IFA IgG Pos | % Agreement<br>Negative* | 95% CI |
|-----------------------------------------------------------------------------|--------------------------|------------|
| CMV | 91.7% (11/12) | 61.5-99.8% |
| EBV VCA | 90.9% (20/22) | 70.8-98.9% |
| HHV6 | 90.9% (20/22) | 70.8-98.9% |
| VZV | 90.5% (19/21) | 69.6-98.8% |
| Total | 90.9% (70/77) | 82.2-96.3% |

* Excludes 3 Western blot positives, and one discrepant that was not analyzed with the Western blot because of insufficient volume

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An internal investigator assessed the device's intra-assay and inter-assay reproducibility Intra-assav & by assaying seven samples in duplicate, twice a day, for twenty days, for a total of forty Inter-assay runs. Two sets of samples were masked duplicates. Reproducibility

An internal investigator assessed the device's inter-lot reproducibility. Five samples were Inter-lot run on three separate days with three separate lots. For one lot, the samples were run in Reproducibility triplicate, and run in duplicate with the other two lots. Each of the three lots had a different lot of Antigen Wells.

An internal investigator and two off-site laboratories assessed the device's inter-Inter-laboratory laboratory reproducibility. Each of the three laboratories ran seven samples in triplicate Reproducibility on three different days. Three points were excluded because an incorrect sample (instead of sample 27) was run one day.

| Sample | Inter- & Intra-assay | | Inter-lot | | Inter-Laboratory | | | |
|--------|----------------------|------------------------|------------------------|---------------|------------------|---------------|------------------------|------------------------|
| | Index<br>Mean | Intra-<br>assay<br>%CV | Inter-<br>assay<br>%CV | Index<br>Mean | Index<br>%CV | Index<br>Mean | %CV of<br>Lab<br>Means | Mean of<br>Lab<br>%CVs |
| 21* | 0.18 | 20.5% | 15.9% | 0.28 | 52.4% | 0.23 | 19.6% | 17.3% |
| 26* | 0.18 | 12.2% | 12.4% | NA | NA | 0.26 | 33.1% | 20.7% |
| 22** | 1.23 | 6.3% | 6.2% | 1.16 | 5.1% | 1.19 | 3.9% | 7.8% |
| 27** | 1.22 | 5.2% | 6.3% | NA | NA | 1.14 | 14.1% | 8.8% |
| 23 | 1.79 | 4.7% | 5.5% | 1.76 | 5.4% | 1.73 | 5.2% | 7.1% |
| 24 | 3.42 | 3.2% | 7.9% | 3.18 | 16.7% | 2.77 | 11.0% | 10.8% |
| 25 | 8.17 | 3.0% | 6.9% | 7.99 | 7.4% | 6.82 | 18.6% | 4.5% |

#### Reproducibility

#21 & #26 are same material. ** #22 & #27 are same material.

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Image /page/6/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is an abstract symbol that resembles three human profiles facing right, with flowing lines beneath them, possibly representing water or movement.

#### 1 2000 FEB

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Mr. Michael J. Wagner, Esq. Senior Regulatory Affairs Specialist MRL Diagnostics, a Focus/MRL Inc. Company 10703 Progress Way Cypress, California 90630

Re: K993724 Trade Name: HSV-2 ELISA IgG Regulatory Class: III Product Code: MYF Dated: January 10, 2000 Received: January 13, 2000

### Dear Mr. Wagner:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (OS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

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Page 2

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at [phone]. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at [phone]. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number [phone] or [phone] or at its internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html".

Sincerely yours,

Steven Butman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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510(k) Number (if known):

K993724

HSV-2 ELISA IgG

Device Name:

Indications for Use:

MRL Diagnostics' HSV-2 ELISA IgG test is intended for qualitatively detecting the presence or absence of human IgG class antibodies to HSV-2 in human sera. In conjunction with the MRL HSV-1 ELISA IgG, the test is indicated for testing sexually active adults or expectant mothers for aiding in the presumptive diagnosis of HSV infection. The predictive value of a positive or negative result depends on the population's prevalence and the pretest likelihood of HSV-2 infection. The performance of this assay has not been established for use in a pediatric population, for neonatal screening, for testing of immunocompromised patients, or for use with automated equipment.

(PLEASE DO NOT WRITE BELOW THIS LINE CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Woody Dubois

(Division Sign-Off)
Division of Clinical Laboratory Devices
510(k) Number K993724

PRESCRIPTION USE X

(Optional Format 3-10-98)