(50 days)
The Diamedix Is-anti-dsDNA an Enzyme Immunoassay (EIA) for the quantitative detection of IgG antibodies to double-stranded (ds) DNA in human serum as an aid in the diagnosis of systemic lupus erythematosus (SLE). These reagents can be used either manually or in conjunction with the MAGO® Plus Automated EIA Processor.
The Is-anti-dsDNA Test Kit System is an enzyme-linked immunosorbent assay (ELISA) for the detection and quantitation of IgG antibodies to DNA in human serum.
Here's a summary of the acceptance criteria and the study details for the Is-anti-dsDNA Test System based on the provided document:
Acceptance Criteria and Device Performance
The acceptance criteria for the Diamedix Is-anti-dsDNA Test System are implied by its performance in comparison to a commercially available anti-dsDNA ELISA test and its clinical sensitivity and specificity in characterized sera. The reported device performance is summarized below:
| Acceptance Criteria Category | Metric (6-Point Calibration) | Reported Device Performance |
|---|---|---|
| Relative Performance | Relative Sensitivity | 96.3% (90.8-99.0% CI) |
| Relative Specificity | 96.0% (93.0-98.0% CI) | |
| Overall Agreement | 96.1% (93.6-97.8% CI) | |
| Clinical Performance | Clinical Specificity (Normals) | 100.0% (98.1-100.0% CI) |
| Clinical Sensitivity (SLE) | 84.8% (73.9-92.5% CI) | |
| Precision (Interassay) | CV% for positive samples | Between 3.9% and 10.9% |
| CV% for negative samples | N/A (0.00 SD) | |
| Linearity | Dose response curve | Sufficiently linear |
Note: For the Single Point Calibration method, the Relative Sensitivity was 99.1% (95.1-100.0% CI), Relative Specificity was 92.6% (88.8-95.4% CI), and Overall Agreement was 94.7% (91.7-96.6% CI). Precision for positive samples with Single Point Calibration also showed comparable CVs.
Study Details
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Test Set Sample Size and Data Provenance:
- Relative Sensitivity and Specificity: 413 samples. These samples comprised 200 sera from normal blood donors, 209 sera from clinical patients with either a diagnosis of SLE or another autoimmune disease, and 4 sera from patients whose status was unknown. The country of origin is not explicitly stated but implies a clinical laboratory setting. The data appears to be retrospective as it involves pre-existing samples.
- Clinical Sensitivity and Specificity: 200 normal samples, 70 sera from patients with a diagnosis of SLE, and 138 sera from patients with suspected autoimmune disease. Data provenance is similar to the relative sensitivity/specificity study – clinical patient samples, likely retrospective.
- Precision: Six sera and kit positive and negative controls were assayed in triplicate in two runs per day.
- Linearity: The WHO Reference preparation, the kit 200 IU/ml Standard, and an in-house reference 200 IU/ml Standard were serially diluted and tested.
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Number of Experts and Qualifications: Not specified in the provided text. The diagnosis of SLE and other autoimmune diseases for the clinical samples would have been established by medical professionals, likely rheumatologists or other specialists.
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Adjudication Method: Not specified. The determination of patient diagnoses (SLE, autoimmune disease, normal) would have relied on established clinical diagnostic criteria, but the specific adjudication method for the samples used in this study is not detailed. Equivocal and "ONS" (Optimal Noise Suppression, likely meaning "Out of Specification" or similar, though not explicitly defined) samples were excluded from calculations in the relative performance study, and equivocal results were excluded from calculations in the clinical performance study.
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Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study: No, an MRMC study was not done. This device is an in-vitro diagnostic (ELISA test) for detecting antibodies, not an imaging or diagnostic AI device that typically involves human readers and AI assistance.
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Standalone (Algorithm Only Without Human-in-the Loop) Performance: Yes, the performance metrics reported are for the standalone device (the Is-anti-dsDNA Test System) either used manually or on the MAGO Plus Automated EIA Processor. There is no human-in-the-loop component described for interpreting the assay results beyond reading the optical density and calculating antibody levels.
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Type of Ground Truth Used:
- For Relative Performance: The ground truth was established by comparison to another "commercially available anti-dsDNA ELISA test with traceability to the WHO Standard." This is a comparative ground truth based on an established reference assay.
- For Clinical Performance: The ground truth was based on "diagnosis of SLE" and "diagnosis of suspected autoimmune disease" for patient groups, and "normal samples." This implies clinical diagnosis as the ground truth.
- For Precision/Linearity: Ground truth is intrinsic to the assay (known concentrations, internal controls, reference standards).
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Training Set Sample Size: Not applicable. This document describes a traditional ELISA diagnostic kit, not a machine learning or AI model that requires a training set in that sense. The "training" and optimization of the assay would have been part of the product development and validation process, but it's not described as a distinct training set for an algorithm.
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How Ground Truth for Training Set was Established: Not applicable, as it's not an AI/ML device with a training set. The assay's performance characteristics (calibration, cut-offs) would have been established using well-defined standards and reference materials during its development.
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FEB 1 8 2000
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: K994424
Applicant Information:
| Date Prepared: | December 29, 1999 |
|---|---|
| Name: | Diamedix Corporation |
| Address: | 2140 N. Miami AvenueMiami, FL 33127 |
| Contact Person: | Dr. Lynne Stirling |
|---|---|
| Phone Number: | 305-324-2354 |
| Fax Number: | 305-324-2585 |
Device Information:
| Trade Name: | Is-anti-dsDNA Test System |
|---|---|
| Common Name: | Anti-DNA EIA Test |
| Classification Name: | Anti-DNA Antibody |
Equivalent Device:
Enzyme Immunoassay Anti-dsDNA Test
Device Description: The Is-anti-dsDNA Test Kit System is an enzyme-linked immunosorbent assay (ELISA) for the detection and quantitation of IgG antibodies to DNA in human serum.
Intended Use: The assay is intended for use in detecting IgG antibodies to dsDNA in a single human serum sample. The results of the assay are to be used as an aid in the diagnosis of SLE.
Principle of the Procedure:
The Is-anti-dsDNA Test System is an enzyme-linked immunosorbent assay to detect IgG antibdies to dsDNA in human serum. Purified plasmid DNA is attached to a solid phase microtiter well. Diluted test sera are added to each well. If antibodies which recognize the DNA antigen are present in the patient sample they will bind to the antigen in the well. After incubation, the wells are washed to remove unbound antibody. An enzyme labeled antihuman immunoglobulin (conjugate) is added to each test well. If antibody is present the enzyme-linked antibody will bind to it. After incubation, the wells are washed to remove unbound conjugate. A substrate solution is then added to each well. If enzyme is present from prior step, the reaction is stopped and the color intensity is measured photometrically producing an indirect measure of the specific antibody present in the patient sample.
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SUMMARY OF SAFETY AND EFFECTIVENESS
Performance Characteristics
A. Comparison Studies : Relative Sensitivity and Specificity
The Diamedix Is-anti-dsDNA Test Kit was evaluated relative to another commercially available antidsDNA ELISA test with traceability to the WHO Standard. A total of 413 samples were tested by both methods. These samples were comprised of two hundred sera from normal blood donors, two hundred and nine sera from clinical patients with either a diagnosis of SLE or another autoimmune disease and four sera from patients whose status was unknown. Performance is summarized in TABLE 1 for both 6-Point and Single Point Calibration using the manual method of testing. Similar results were obtained using the MAGO Plus automated testing method.
| and been been been been been been and en de sent of the bestille beginnen with and the bestille of the bestille be | ||||||
|---|---|---|---|---|---|---|
| 6-Point Calibration | Single Point Calibration | |||||
| # of sera | 90 | 95% CI | # of sera | % | 95% CI | |
| Relative Sensitivity | 104/108 | 96.3 | 90.8-99.0 | 111/112 | 99.1 | 95.1-100.0 |
| Relative Specificity | 264/275 | 96.0 | 93.0-98.0 | 251/271 | 92.6 | 88.8-95.4 |
| Overall Agreement* | 368/383 | 96.1 | 93.6-97.8 | 362/383 | તેવ વિત્તર જેવી સાથે છે. આ ગામનાં પ્રાથમિક શાળા, પંચાયતઘર, આંગણવાડી તેમ જ દૂધની ડેરી જેવી સવલતો પ્રાપ્ય થયેલી છે. આ ગામનાં પ્રાથમિક શાળા, પંચાયતઘર, આંગણવાડી તેમ જ દૂધની ડેરી | 91.7-96.6 |
| TABLE4P1 | - |
|---|---|
| ---------------------- | --- |
- Equivocal and ONS samples were excluded from calculations
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 judgment can be made on the comparison's accuracy to predict disease.
B. Clinical Sensitivity and Specificity Using Characterized Sera
Clinical sensitivity and specificity was assessed by evaluating the results from each patient group . The groups consisted of 200 normal samples, 70 sera from patients with a diagnosis of SLE and 138 sera from patients with suspected autoimmune disease. The results presented in TABLE 2 were obtained manually using the 6-Point calibration method.
| Patient Group: | Positive | Equivocal* | Negative | Total |
|---|---|---|---|---|
| Normals | 0 | 3 | 197 | 200 |
| SLE | 56 | 4 | 10 | 70 |
| Autoimmune Disease | 63 | 5 | 70 | 138 |
| Clinical Specificity: | 95% CI | |||
| Normals | = 197/197 = 100.0% | 98.1-100.0 | ||
| Clinical Sensitivity: | 95% CI | |||
| SLE patients | = 56/66 = 84.8% | 73.9-92.5 |
73.9-92.5
TARI F 2
Autoimmune disease patients = 63/133 = 47.4% 38.9-55.9
- Equivocal results were excluded from calculations
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C. Precision
The precision of the Is-anti-dsDNA Test Kit when performed either manually or on the MAGO Plus Automated EIA Processor using the 6-Point calibration method was determined by assaying six sera and the kit positive and negative controls in triplicate in two runs per days. TABLES 3 and 4 show the intra-and interassay precision obtained. Comparable CVs for positive samples were also obtained when precision testing was performed using the Single Point calibration method (data on file).
| SERUM | INTRA-ASSAY DAY 1 | INTRA-ASSAY DAY 2 | INTRA-ASSAY DAY 3 | INTERASSAY | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MEANIU/ml | SD | CV% | MEANIU/ml | SD | CV% | MEANIU/ml | SD | CV% | MEANIU/ml | SD | CV% | |
| A (NEG) | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A |
| B (NEG) | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A |
| C (POS) | 49.3 | 5.17 | 10.5 | 48.5 | 7.12 | 14.7 | 45.1 | 0.95 | 2.1 | 47.6 | 5.17 | 10.9 |
| D (POS) | 68.5 | 6.88 | 10.0 | 62.3 | 5.45 | 8.8 | 66.9 | 1.95 | 2.9 | 65.9 | 5.59 | 8.5 |
| E (POS) | 96.6 | 5.89 | 6.1 | 90.5 | 8.16 | 9.0 | 79.2 | 4.51 | 5.7 | 88.7 | 9.53 | 10.7 |
| F (POS) | 152.4 | 4.06 | 2.7 | 156.9 | 8.61 | 5.5 | 150.3 | 1.59 | 1.1 | 153.2 | 5.95 | 3.9 |
| POS CTRL | 69.1 | 5.57 | 8.1 | 70.3 | 2.99 | 4.3 | 66.4 | 2.20 | 3.3 | 68.6 | 4.00 | 5.8 |
| NEG CTRL | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A | 0.0 | 0.00 | N/A |
TABLE 3: Intra-Assay and Interassay Precision-Manual Testing
TABLE 4 : Intra-Assay and Interassay Precision - MAGO Plus Testing
| SERUM | INTRA-ASSAY DAY 1 | INTRA-ASSAY DAY 2 | INTRA-ASSAY DAY 3 | INTERASSAY | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MEANIU/ml | SD | CV% | MEANIU/ml | SD | CV% | MEANIU/ml | SD | CV% | MEANIU/ml | SD | CV% | |
| A (NEG) | 0.0 | 0.00 | 0.0 | 0.0 | 0.00 | 0.0 | 0.0 | 0.00 | 0.0 | 0.0 | 0.00 | 0.0 |
| B (NEG) | 0.0 | 0.00 | 0.0 | 2.1 | 2.90 | 0.0 | 0.0 | 0.00 | 0.0 | 0.0 | 0.00 | 0.0 |
| C (POS) | 52.9 | 3.55 | 6.7 | 51.3 | 2.80 | 5.5 | 52.6 | 3.26 | 6.2 | 52.3 | 3.11 | 5.9 |
| D (POS) | 76.0 | 5.02 | 6.6 | 76.8 | 3.14 | 4.1 | 72.9 | 5.19 | 7.1 | 75.2 | 4.61 | 6.1 |
| E (POS) | 80.0 | 9.54 | 11.9 | 81.6 | 6.58 | 8.1 | 89.7 | 7.36 | 8.2 | 83.8 | 8.63 | 10.3 |
| F (POS) | 164.6 | 7.49 | 4.6 | 158.1 | 11.40 | 7.2 | 162.0 | 11.40 | 7.0 | 161.6 | 10.00 | 6.2 |
| POS CTRL | 76.5 | 2.28 | 3.0 | 75.6 | 2.04 | 2.7 | 74.2 | 3.08 | 4.1 | 75.4 | 2.54 | 3.4 |
| NEG CTRL | 0.0 | 0.00 | 0.0 | 0.0 | 0.00 | 0.0 | 0.0 | 0.00 | 0.0 | 0.0 | 0.00 | 0.0 |
D. Linearity
The dose response curve for the Is-anti-dsDNA test kit is sufficiently linear to allow for the use of either 6-Point or Single Point calibration systems. This linearity is illustrated in FIGURES 1 and 2. These figures depict samples that have been serially diluted in Sample Dilution tested and results determined using either calculation method. The samples selected were the WHO Reference preparation, the kit 200 IU/ml Standard and the in-house reference 200 IU/ml Standard. Recovered IU/ml values for each dilution were determined using either the 6-Point (FIGURE 1) or Single Point (FIGURE 2) calibration methods. The linearity data shown was obtained using the manual method of testing. Similar results were obtained using the MAGO Plus automated method.
Image /page/2/Figure/8 description: The image contains two figures, labeled as FIGURE 1 and FIGURE 2. FIGURE 1 shows a graph of Kit Standards (IU/ml) on the x-axis and Recovered Values (IU/ml) on the y-axis, with values ranging from 0 to 300. FIGURE 2 shows a graph of DILUTION on the x-axis and Recovered Values (IU/ml) on the y-axis, with dilution values ranging from 0.0 to 1.0. Both figures plot three different lines: Kit 200 IU/ml STD, In-house Ref STD, and WHO Ref, showing the relationship between the x and y axis for each of the three lines.
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Image /page/3/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" arranged around the perimeter. Inside the circle is a stylized image of a caduceus, which is a symbol often associated with medicine and healthcare. The caduceus in the logo is depicted with a staff and a serpent winding around it.
FEB 1 8 2000
Food and Drug Administration 2098 Gaither Road Rockville MD 20850
Lynne Stirling, Ph.D. Vice President, Regulatory Affairs Diamedix® Corporation 2140 North Miami Avenue Miami, Florida 33127
Re: K994424 Trade Name: Is-anti-dsDNA Test System Regulatory Class: II Product Code: LRM Dated: December 29, 1999 Received: December 30, 1999
Dear Dr. Stirling:
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 (QS) 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 (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. 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 (800) 638-2041 or (301) 443-6597 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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Appendix G. Indications for Use Statement
INDICATIONS FOR USE STATEMENT
510(K) NUMBER : K994434
DEVICE NAME : Is-anti-dsDNA Test System
Indications for Use :The Diamedix Is-anti-dsDNA an Enzyme Immunoassay (EIA) for the quantitative detection of IgG antibodies to double-stranded (ds) DNA in human serum as an aid in the diagnosis of systemic lupus erythematosus (SLE). These reagents can be used either manually or in conjunction with the MAGO® Plus Automated EIA Processor.
Peter E. Magni
(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use V (Per 21 CFR 801.109)
OR
Over-The-Counter Use
(Optional Format 1-2-96)
§ 866.5100 Antinuclear antibody immunological test system.
(a)
Identification. An antinuclear antibody immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the autoimmune antibodies in serum, other body fluids, and tissues that react with cellular nuclear constituents (molecules present in the nucleus of a cell, such as ribonucleic acid, deoxyribonucleic acid, or nuclear proteins). The measurements aid in the diagnosis of systemic lupus erythematosus (a multisystem autoimmune disease in which antibodies attack the victim's own tissues), hepatitis (a liver disease), rheumatoid arthritis, Sjögren's syndrome (arthritis with inflammation of the eye, eyelid, and salivary glands), and systemic sclerosis (chronic hardening and shrinking of many body tissues).(b)
Classification. Class II (performance standards).