DIAMEDIX IS-ANTI-B2 GLYCOPROTEIN I SCREEN

K013956 · Diamedix Corp. · MSV · Jan 8, 2002 · Immunology

Device Facts

• Record ID: K013956
• Device Name: DIAMEDIX IS-ANTI-B2 GLYCOPROTEIN I SCREEN
• Applicant: Diamedix Corp.
• Product Code: MSV · Immunology
• Decision Date: Jan 8, 2002
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.5660
• Device Class: Class 2

Intended Use

The Diamedix Is anti-β,Glycoprotein I Screen Test Kit is an indirect enzyme immunoassay (EIA) for the semi-quantitative measurement of IgG, IgM and IgA antibodies to ß, glycoprotein I in human serum as an aid in the diagnosis of certain autoimmune thrombotic disorders in patients with SLE or SLE-like disorders. These reagents can be used either manually or in conjunction with the MAGO® Plus Automated EIA Processor.

Device Story

Indirect solid-phase enzyme immunoassay (ELISA) for human serum; detects IgG, IgM, and IgA antibodies to β2-glycoprotein I. Procedure: purified β2-glycoprotein I coated on microwells; patient samples added; bound antibodies detected via anti-human horseradish peroxidase conjugate; substrate added to produce color change; reaction stopped with acid. Output: spectrophotometric reading at 450 nm (reference 600-630 nm) proportional to antibody concentration. Used in clinical laboratories; operated by technicians. Can be performed manually or using MAGO Plus Automated EIA Processor. Results aid clinicians in diagnosing autoimmune thrombotic disorders in SLE patients.

Clinical Evidence

Retrospective study of 387 clinically characterized sera (248 normal, 57 APS, 33 SLE, 34 other autoimmune, 15 RPR positive). Clinical sensitivity: 84.2% for APS, 30.3% for SLE. Clinical specificity: 96.8% for normals, 86.7% for RPR positive, 88.2% for other autoimmune diseases. Relative sensitivity/specificity compared to another EIA: 71.6% and 100% respectively. Correlation between manual and MAGO Plus automated methods: r=0.9667.

Technological Characteristics

Solid-phase ELISA; highly purified β2-glycoprotein I antigen coated on plastic microwells. Detection via horseradish peroxidase conjugate and spectrophotometric measurement at 450 nm. Compatible with manual processing or MAGO Plus Automated EIA Processor. No specific material standards (e.g., ASTM) cited.

Indications for Use

Indicated for semi-quantitative measurement of IgG, IgM, and IgA antibodies to β2-glycoprotein I in human serum to aid in diagnosing autoimmune thrombotic disorders in patients with SLE or SLE-like disorders.

Regulatory Classification

Identification

A multiple autoantibodies immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the autoantibodies (antibodies produced against the body's own tissues) in serum and other body fluids. Measurement of multiple autoantibodies aids in the diagnosis of autoimmune disorders (disease produced when the body's own tissues are injured by autoantibodies).

Predicate Devices

• Inova QUANTA Lite ß,GPI Screen

Submission Summary (Full Text)

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## 510(k) Summary of Safety and Effectiveness

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.

The assigned 510(k) number is: K013956

## Applicant Information:

| Date Prepared: | December 20, 2001 |
|----------------|-----------------------------------------|
| Name: | Diamedix Corporation |
| Address: | 2140 N. Miami Avenue<br>Miami. FL 33127 |

| Contact Person: | Dr. Lynne Stirling |
|-----------------|--------------------|
| Phone Number: | 305-324-2354 |
| Fax Number: | 305-324-2388 |

## Device Information:

| Trade Name: | Is anti-β₂Glycoprotein I Screen Test System |
|----------------------|-------------------------------------------------|
| Common Name: | Anti-β₂Glycoprotein I ELISA test |
| Classification Name: | Anti-β₂Glycoprotein I immunological test system |

## Equivalent Device:

Inova QUANTA Lite ß,GPI Screen

Device Description: The Is anti B, Glycoprotein I Screen Test System is an enzyme-linked immunosorbent assay (ELISA) for the semi-quantitative measurement of IgG, IgM and IgA antibodies to ß, glycoprotein I in human serum

Intended Use: The assay is intended for the semi-quantitative measurement of IgG, IgM and IgA antibodies to B.glycoprotein I in human serum. The results of the assay can be used as an aid in the diagnosis of certain autoimmune thrombotic disorders in patients with SLE or SLE-like disorders.

## Principle of the Procedure:

The Is anti B.Glycoprotein I Screen Test System is an indirect solid-phase enzyme immunoassay. Highly purified ß2 glycoprotein I is coated onto plastic microwells. Controls and diluted patient samples are added to the wells. Any patient IgG, IgM or IgA antibodies in the sample bind to the well. Anti-human horseradish peroxidase conjugate is then added After incubation and washing, a substrate solution is then added to each well. In the presence of bound enzyme, the substrate is converted to a blue colored product. After acid addition to stop the reaction, a yellow end product is formed that is read spectrophotometrically at 450 nm (reference 600-630 nm) and is directly proportional to the concentration of B2 glycoprotein I IgG, IgM and IgA antibodies in the sample.

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# SUMMARY OF SAFETY AND EFFECTIVENESS

## Performance Characteristics

All non-clinical performance studies were performed using the manual method unless otherwise indicated.

## A. Relative Sensitivity and Specificity

One hundred and eighty-seven frozen, retrospective sera were tested for IgG/IgM/IgA B,glycoprotein I antibodies using the Is anti-ß, Glycoprotein I Screen Test Kit and a commercially available ELISA kit for detecting B.glycoprotein I IgG/IgM/IgA antibodies. Based on the results of this testing the relative sensitivity, relative specificity and overall agreement were calculated. The results obtained are shown in TABLE 1. Further resolution of the discordant samples showed that three samples that were negative in the Is anti-B.Glycoprotein I Screen and positive by the other EIA were negative by a referee EIA method. The remaining twenty-two discordant samples were positive in the referee test. Note that 17 of the 25 discordant samples were from normal blood donors with no history of disease.

TABLE 1

| | | Is-anti-β₂Glycoprotein I Screen | | |
|----------------------|------------|---------------------------------|----------|-------------|
| | | Positive | Negative | *Equivocal |
| Other<br>EIA | Positive | 63 | 25 | 4 |
| | Negative | 0 | 95 | 0 |
| | *Equivocal | 0 | 0 | 0 |
| | | | | **95% CI |
| Relative Sensitivity | | 63/88 | = 71.6 % | 61.0-80.7% |
| Relative Specificity | | 95/95 | = 100.0% | 96.2-100.0% |
| Overall Agreement | | 158/183 | = 86.3% | 81.4-91.3% |

* Equivocal results were excluded from calculations. ** 95% Confidence Intervals (CI) calculated by the Exact Method.

NOTE : Please be advised that 'relative' refers to the assay's results to that of a similar assay. There was not an attempt to correlate the assay's results with disease presence or absence. No judgement can be made on the comparison's accuracy to predict disease.

## B. Clinical Sensitivity and Specificity

A total of three hundred and eighty-seven frozen retrospective, clinically characterized sera were assayed using the Is anti-B. Glycoprotein I Screen Test Kit in order to assess both the clinical sensitivity and clinical specificity of the test system. These samples consisted of 248 normal sera, 57 sera from patients with diagnosed anti-phospholipid syndrome (APS), 33 sera from patients with systemic lupus erythematosus (SLE), 34 sera from patients with other autoimmune diseases such as Sjogren's Syndrome, polymyositis/dermatomyositis and theumatoid arthritis and 15 samples from patients with positive RPR titers. Results are summarized in TABLE 2.

| TABLE 2 | | | | |
|------------------------------|-------------------|------------|------------|-----------|
| Patient Group | Total | # Positive | # Negative | Equivocal |
| Normals | 248 | 6 | 240 | 2 |
| APS | 57 | 48 | 7 | 2 |
| SLE | 33 | 10 | 21 | 2 |
| Other Autoimmune<br>Diseases | 34 | 4 | 30 | 0 |
| RPR Positive | 15 | 1 | 13 | 1 |
| Clinical Specificity: | | | | |
| Normals | $240/248 = 96.8%$ | | | |
| RPR Positive | $13/15 = 86.7%$ | | | |
| Other Autoimmune<br>Diseases | $30/34 = 88.2%$ | | | |
| Clinical Sensitivity : | | | | |
| APS | $48/57 = 84.2%$ | | | |
| SLE | $10/33 = 30.3%$ | | | |

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#### C. Correlation of Manual and MAGO Plus results

The Is anti-B,Glycoprotein I Screen Test Kit has been developed for automated as well as manual use. To demonstrate the equivalence of the manual and MAGO Plus procedures, the results of 305 serum samples tested for anti-glycoprotein I IgG/IgM/IgA antibodies by both the manual and automated methods, and whose were within the reportable range of the assay, were plotted. Scattergrams and regression lines of the results obtained with 95% confidence intervals are shown in FIGURE 1. The data indicate good correlation with a Correlation Coefficient (r) of 0.9667.

Image /page/2/Figure/2 description: The figure is titled "FIGURE 1: Is anti-β, Glycoprotein I Screen Manual vs MAGO Plus Correlation". It is a scatter plot that shows the correlation between the manual and MAGO Plus methods for screening anti-β, Glycoprotein I. The x-axis represents the manual U/ML, and the y-axis represents the MAGO Plus U/ML. The data points are clustered around a diagonal line, indicating a positive correlation between the two methods. The x and y axis both range from 0 to 80, and 0 to 100 respectively.

#### D. Linearity

To assess the linearityof the Is anti-B, Glycoprotein I Screen Test Kit, several highly positive samples were serially diluted using Sample Diluent and each dilution was then tested in the assay system. A representative linear regeression graph and scattergram with 95% confidence intervals is shown in FIGURE 2.

Image /page/2/Figure/5 description: The image shows a scatter plot with a linear regression line and confidence intervals. The x-axis is labeled "DILUTION" and ranges from 0.0 to 0.5. The y-axis is labeled "CONC" and ranges from -20 to 140. The data points are scattered around the regression line, indicating a positive correlation between dilution and concentration.

Image /page/2/Figure/6 description: The image is a title that reads "FIGURE 2: Is anti-ß, Glycoprotein I Screen Linearity". The title is written in a bold, sans-serif font. The text is centered on the page. The title is likely from a scientific paper or presentation.

Regression Equation Y=5.1789 + 217.8194 X

Intercept 5.17893 Slope 217.81940 Coefficient of Determination = 0.9808 Correlation Coefficient r =0.9904 95% CI for r 0.9456 to 0.9983

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#### E. Precision

To assess the precision of the Is anti-b Glycoprotein I Screen Test Kit six serum samples of varying reactivity (two negative To assess the precision of the of cription in three separate runs. Precision was assessed both manually and using the and four positive) were teles an alpas. The results obtained are shown in TABLES 3 and 4.

TABLE 3 : Manual Intra-Assay and Interassay Precision for Is-anti-B,Glycoprotein I Screen

| SERUM | INTRA-ASSAY RUN 1 | | | INTRA-ASSAY RUN 2 | | | INTRA-ASSAY RUN 3 | | | INTERASSAY (n=9) | | |
|-------|-------------------|-------|------|-------------------|-------|------|-------------------|-------|------|------------------|-------|-------|
| | MEAN<br>U/ml | SD | CV% | MEAN<br>U/ml | SD | CV% | MEAN<br>U/ml | SD | CV% | MEAN<br>U/ml | SD | CV% |
| A | 3.8 | 0.200 | 5.26 | 3.6 | 0.115 | 3.24 | 3.9 | 0.252 | 6.51 | 3.7 | 0.219 | 5.84 |
| B | 3.5 | 0.153 | 4.41 | 3.0 | 0.153 | 5.15 | 3.8 | 0.173 | 4.56 | 3.4 | 0.389 | 11.40 |
| C | 20.0 | 0.723 | 3.62 | 17.7 | 1.137 | 6.41 | 19.2 | 1.153 | 6.01 | 19.0 | 1.324 | 6.98 |
| D | 30.8 | 1.172 | 3.81 | 26.7 | 0.764 | 2.86 | 27.1 | 0.361 | 1.33 | 28.2 | 2.062 | 7.31 |
| E | 49.7 | 2.818 | 5.67 | 44.4 | 0.755 | 1.70 | 45.1 | 1.159 | 2.57 | 46.4 | 2.927 | 6.31 |
| F | 92.4 | 1.044 | 1.13 | 89.3 | 1.150 | 1.29 | 90.3 | 0.624 | 0.69 | 90.7 | 1.616 | 1.78 |

TABLE 4 : MAGO Plus Intra-Assay and Interassay Precision for Is-anti-β,Glycoprotein I Screen

| SERUM | | INTRA-ASSAY RUN 1 | | | INTRA-ASSAY RUN 2 | | | INTRA-ASSAY RUN 3 | | | INTERASSAY (n=9) | | |
|-------|--------------|-------------------|-------|--------------|-------------------|-------|--------------|-------------------|-------|--------------|------------------|-------|--|
| | MEAN<br>U/ml | SD | CV% | MEAN<br>U/ml | SD | CV% | MEAN<br>U/ml | SD | CV% | MEAN<br>U/ml | SD | CV% | |
| A | 7.6 | 0.781 | 10.28 | 5.1 | 0.557 | 10.92 | 6.4 | 0.874 | 13.58 | 6.4 | 1.263 | 19.80 | |
| B | 5.7 | 0.874 | 15.24 | 4.8 | 0.379 | 7.94 | 5.4 | 0.100 | 1.85 | 5.3 | 0.640 | 12.08 | |
| C | 24.9 | 2.955 | 11.87 | 19.0 | 1.976 | 10.38 | 27.1 | 1.200 | 4.43 | 23.7 | 4.069 | 17.19 | |
| D | 35.7 | 2.307 | 6.47 | 38.6 | 4.452 | 11.52 | 47.3 | 0.917 | 1.94 | 40.5 | 5.823 | 14.36 | |
| E | 71.1 | 4.319 | 6.07 | 69.3 | 7.238 | 10.44 | 59.0 | 3.630 | 6.15 | 66.5 | 7.277 | 10.94 | |
| F | 139.7 | 11.920 | 8.53 | 154.1 | 19.248 | 12.49 | 146.2 | 10.336 | 7.07 | 146.7 | 13.910 | 9.48 | |

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# Expected Values

The prevalence of anti-b,glycoprotein I antibodies may vary depending on a number of factors such as age, I he provises of and location, race, type of test used and clinical history of individual patients. Antibodies to anti-p.glycoprotein I are generally absent, or have a very low incidence, in the normal healthy population.

In the present study, the expected values for a normal, healthy population were assessed by testing sera from one hundred and forty-eight S. Florida blood donors (ninety-eight males and fifty females) in the Is anti- B. Glycoprotein I Screen Test Kit. One hundred and forty-one sera (95.3%) were negative for antibodies, five sera (3.4%) were positive and two (1.3%) were equivocal. The age distribution and antibody prevalence for this population are shown in TABLE 5.

The expected values for a clinical population were assessed by testing fifty-seven sera from patients with a I in chipose of anti-phospholipid syndrome (APS) in the Is anti-β Glycoprotein I Screen Test Kit. Forty-eight (84.2%) were positive, seven (12.3%) were negative and two (3.5%) were equivocal for IgG/IgM/IgA antibodies.

Histograms showing the distribution of values for these normal and clinical populations are shown in FIGURES 3 and 4.

| | Number of Donors | Prevalence |
|-------------------------|---------------------|------------|
| Total Number | 148 | |
| Geographic<br>Location: | South Florida : 148 | 3.4% |
| Age | | |
| 10-19 | 7 | 14.3% |
| 20-29 | 36 | 2.8% |
| 30-39 | 73 | 1.4% |
| 40-49 | 22 | 9.1% |
| 50-59 | 8 | 0.0% |
| 60-69 | 2 | 0.0% |

## TABLE 5 : Age Distribution and Prevalence of anti-β.Glycoprotein I IgG/IgM/IgA in a Normal S. Florida Population

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Image /page/5/Figure/0 description: This image is labeled as "FIGURE 3" and shows the distribution of anti-B.alvcoproteinl laG/laM/laA values in a normal population. The figure provides information about the levels of these antibodies in a healthy group of individuals. The image appears to be a title or heading for a scientific figure.

Image /page/5/Figure/1 description: The image is a histogram showing frequency on the y-axis and U/ML on the x-axis. The histogram shows a large bar at the beginning, indicating a high frequency for low U/ML values. There is a smaller bar at around 15 U/ML, and then a few very small bars between 90 and 110 U/ML. The frequency reaches a maximum of 140.

FIGURE 4

DIstribution of anti-β¸glycoprotein I igG/IgM/ IgA Values in a Clinical Population

Image /page/5/Figure/4 description: This image is a histogram showing frequency on the y-axis and U/ML on the x-axis. The frequency ranges from 0 to 9, and the U/ML ranges from 0 to 120. The histogram shows the distribution of data points across different intervals, with the highest frequencies observed around 0 and 120 U/ML.

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Image /page/6/Picture/1 description: The image shows the seal of the U.S. Department of Health and Human Services. The seal features a stylized eagle with three stripes, representing the three branches of government. The seal is surrounded by the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" in a circular arrangement.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

8 2002 JAN

Lynne Stirling, Ph.D. Vice President, Regulatory Affairs Diamedix Corporation 2140 N. Miami Avenue Miami, FL 33127

Re: k013956

Trade/Device Name: Is anti-ß2 Glycoprotein I Screen Test System Regulation Number: 21 CFR 866.5660 Regulation Name: Multiple autoantibodies immunological test system Regulatory Class: Class II Product Code: MSV Dated: November 28, 2001 Received: November 30, 2001

Dear Dr. Stirling:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and 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) that do not require approval of a premarket approval application (PMA). 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 (PMA), 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 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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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 International and Consumer 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 Sutman

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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# INDICATIONS FOR USE STATEMENT

510(K) NUMBER : _ K013956

## DEVICE NAME : Is anti-ß,Glycoprotein I Screen Test System

Indications for Use : The Diamedix Is anti-β,Glycoprotein I Screen Test Kit is an indirect enzyme immunoassay (EIA) for the semi-quantitative measurement of IgG, IgM and IgA antibodies to ß, glycoprotein I in human serum as an aid in the diagnosis of certain autoimmune thrombotic disorders in patients with SLE or SLE-like disorders. These reagents can be used either manually or in conjunction with the MAGO® Plus Automated EIA Processor.

# PLEASE DO NOT WRITE BELOW THIS LINE- CONTINUE ON ANOTHER PAGE IF NEEDED.

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use: _

OR

Over-The-Counter (OTC) Use

(Per 21CFR 801.109)

(Optional Format 1-2-96).

D.H.S.

Division of Clinical Laboratory Devices K013956 510(k) Number