(109 days)
The Access Syphilis assay is a paramagnetic particle, chemiluminescent immunoassay for the qualitative detection of total antibodies to Treponema pallidum in human serum and plasma using the Access lmmunoassay Systems. It is intended to be used as an aid in the diagnosis of syphilis or in conjunction with a nontreponemal laboratory test and clinical findings to aid in the diagnosis of syphilis infection. The Access Syphilis assay is not intended for blood and tissue donor screening.
The Access Syphilis assay is a two-step enzyme immunoassay. A sample is added to a reaction vessel with buffer, paramagnetic particles coated with recombinant Treponema pallidum antigens Tp17 and Tp47, and Tp47, and biotinylated Treponema Tp17 & Tp47 antigens. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Alkaline phosphatase conjugates are added, and the conjugates bind to the immunoglobulin captured on the particles. A chemilyminescent substrate is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is proportional to the amount of Treponema pallidum antibodies in the sample. The light quantity measured for a sample allows a determination of the presence of the analyte by comparison with a cut-off value defined during the assay calibration on the instrument. The Access Syphilis reagents are provided in liquid ready-to-use format designed for optimal performance on the Beckman Coulter Access Immunoassay Systems. Each reagent kit contains two reagent packs.
The Access Syphilis assay is a qualitative immunoassay for detecting total antibodies to Treponema pallidum in human serum and plasma, used as an aid in diagnosing syphilis. The device was evaluated for its clinical performance on two systems: the Access 2 Immunoassay System and the Dxl 9000 Access Immunoassay Analyzer. The acceptance criteria and performance data are primarily based on percent agreement with a composite reference method.
Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance:
The document does not explicitly state pre-defined acceptance criteria values for Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA). However, the results presented are implicitly the "performance" that aims to demonstrate substantial equivalence. The following table summarizes the reported performance in key clinical evaluation cohorts:
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance (Access 2 & Dxl 9000) |
|---|---|---|
| PPA (Overall Intended Use Population) | High agreement expected, generally >95% | 100% (184/184) [95% CI: 98.0 - 100%] |
| NPA (Overall Intended Use Population) | High agreement expected, generally >95% | 96.7% (890/920) [95% CI: 95.4 - 97.7%] |
| PPA (Retrospective Specimens) | High agreement expected, generally >95% | 100% (398/398) [95% CI: 99.0 - 100%] |
| NPA (Retrospective Specimens) | High agreement expected, generally >95% | 25.0% (1/4) [95% CI: 4.6 - 69.9%] * |
| PPA (High-Risk Individuals) | High agreement expected, generally >95% | 100% (20/20) [95% CI: 83.9 - 100%] |
| NPA (High-Risk Individuals) | High agreement expected, generally >95% | 80.0% (24/30) [95% CI: 62.7 - 90.5%] |
*Note on NPA for Retrospective Specimens: The low NPA for retrospective specimens is due to a very small number of non-reactive specimens in the comparator (only 4), making the percentage highly sensitive to a single misclassification. The 31 reactive results from Access Syphilis where the comparator was nonreactive need further investigation, which the document attributes to "3 specimens were reactive by treponemal immunoassay and nonreactive by RPR and TPPA". This suggests potential discordance with the composite comparator definition for these few cases rather than a broad failing of the device's negative detection.
2. Sample Size for the Test Set and Data Provenance:
The study involved a total of 1,910 specimens for clinical performance evaluation. These specimens were broadly characterized as:
- 1,104 prospectively collected specimens from the intended use population. The age range was 12 to >89 years, with 63.8% female and 36.2% male. This cohort included:
- 399 patients sent for syphilis testing
- 405 pregnant women
- 300 HIV positive patients
- 402 retrospective specimens from patients (including 22 from pregnant females).
- 204 prospectively collected specimens from apparently healthy individuals.
- 150 retrospective specimens from patients with medically diagnosed syphilis (primary, secondary, and latent stages).
- 50 retrospective specimens from individuals at high-risk of sexually transmitted disease.
The provenance of the data is multicenter, meaning specimens were collected from multiple clinical sites. Both retrospective and prospective data were used. The document does not explicitly state the country of origin, but the submission to the U.S. FDA suggests a U.S. or international clinical setting adhering to FDA standards.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts:
The document does not mention the use of human experts to establish the ground truth for the test set in the traditional sense (e.g., radiologists interpreting images). Instead, the "final comparator result" (ground truth) was established using a composite testing algorithm of multiple FDA-approved laboratory assays, which is standard practice for in vitro diagnostic devices.
4. Adjudication Method for the Test Set:
The adjudication method used a composite testing algorithm as the "final comparator result." This algorithm consisted of:
- An FDA-approved predicate treponemal immunoassay.
- A non-treponemal assay (RPR - Rapid Plasma Reagin).
- A second treponemal assay (TPPA - Treponema Pallidum Particle Agglutination).
The document does not detail a specific "2+1" or "3+1" adjudication process involving human review for discordant results beyond the internal algorithmic comparison. However, for discordant results in the HIV positive patient subpopulation (where the Access Syphilis assay showed lower NPA), an additional FDA-cleared electrochemiluminescent immunoassay was used to further evaluate 28 discordant specimens.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done:
No, an MRMC comparative effectiveness study was not done. This device is an in vitro diagnostic assay, not an imaging AI device that involves human readers interpreting images with or without AI assistance. The performance is assessed by comparing the device's output to established laboratory reference methods, not human interpretation.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Yes, the clinical performance study is a standalone performance evaluation. The Access Syphilis assay is an automated immunoassay system that provides results independently. Its performance (reactive/non-reactive) is directly compared against the composite reference standard without human interpretation of the assay's raw output.
7. The type of ground truth used:
The ground truth was established using a composite testing algorithm consisting of results from:
- An FDA-approved predicate treponemal immunoassay.
- A non-treponemal assay (RPR).
- A second treponemal assay (TPPA).
This acts as a "reference standard" or "expert consensus" in the context of laboratory diagnostics, where consensus among multiple established tests determines the final disease status. In some cases, "medically diagnosed syphilis" for specific retrospective cohorts also contributed to the understanding of the samples.
8. The sample size for the training set:
The document does not specify a separate training set size for the Access Syphilis assay. As a chemiluminescent immunoassay, it is a biochemical test, not an AI/machine learning algorithm that typically requires a discrete "training set" in the same way. The assay's parameters would have been optimized during its development phase using internal studies, but these are not referred to as a "training set" in the context of typical AI device submissions.
9. How the ground truth for the training set was established:
Since a distinct "training set" in the AI/ML sense is not described, the method for establishing its ground truth is not applicable in the document. The development of an immunoassay involves extensive analytical and clinical validation, which ensures the reagents and system accurately detect the target antibodies. This process implicitly refines the assay's performance against known positive and negative samples, similar to how a training set might function for an algorithm.
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Beckman Coulter, Inc Brenda Eifert Staff Regulatory Affairs 1000 Lake Hazeltine Drive Chaska, Minnesota 55318
Re: K241427
Trade/Device Name: Access Syphilis Regulation Number: 21 CFR 866.3830 Regulation Name: Treponema Pallidum Treponemal Test Reagents Regulatory Class: Class II Product Code: LIP Dated: May 17, 2024 Received: May 20, 2024
Dear Brenda Eifert:
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 (the 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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to 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.
Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device"
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(https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30. Design controls; 21 CFR 820.90. Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review. the OS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
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 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safetyreporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rue"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advicecomprehensive-regulatory-assistance/unique-device-identification-system-udi-system.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
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Sincerely, Himani Bisht -S
Himani Bisht, Ph.D. Assistant Director Viral Respiratory and HPV Branch Division of Microbiology Devices OHT7: Office of In Vitro Diagnostics and Radiological Health Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
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Indications for Use
Submission Number (if known)
K241427 Device Name
Access Syphilis
Indications for Use (Describe)
The Access Syphilis assay is a paramagnetic particle, chemiluminescent immunoassay for the qualitative detection of total antibodies to Treponema pallidum in human serum and plasma using the Access lmmunoassay Systems. It is intended to be used as an aid in the diagnosis of syphilis or in conjunction with a nontreponemal laboratory test and clinical findings to aid in the diagnosis of syphilis infection. The Access Syphilis assay is not intended for blood and tissue donor screening.
Type of Use (Select one or both, as applicable)
< Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
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510(k) Summarv
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.
510(k) Number: K241427
Date Prepared: September 6, 2024
Submitter Name and Address:
Beckman Coulter, Inc 1000 Lake Hazeltine Drive Chaska. MN 55318
Primary Contact:
Brenda Eifert Staff Requlatory Affairs Email: beifert@beckman.com Phone: (800) 854-3633
Alternate Contact: Loretta Lydon O'Toole
Staff Requlatory Affairs Email: lotoole@beckman.com Phone: (800) 854-3633
Trade Name: Access Syphilis Common Name: Treponema pallidum treponemal test reagents Classification Requlation: 21 CFR 866.3830 Classification Product Code: LIP
Predicate Device: Abbott ARCHITECT™ Syphilis TP. 8D06
Device Description
The Access Syphilis assay is a two-step enzyme immunoassay. A sample is added to a reaction vessel with buffer, paramagnetic particles coated with recombinant Treponema pallidum antigens Tp17 and Tp47, and Tp47, and biotinylated Treponema Tp17 & Tp47 antigens. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Alkaline phosphatase conjugates are added, and the conjugates bind to the immunoglobulin captured on the particles. A chemilyminescent substrate is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is proportional to the amount of Treponema pallidum antibodies in the sample. The light quantity measured for a sample allows a determination of the presence of the analyte by comparison with a cut-off value defined during the assay calibration on the instrument.
The Access Syphilis reagents are provided in liquid ready-to-use format designed for optimal performance on the Beckman Coulter Access Immunoassay Systems. Each reagent kit contains two reagent packs.
Intended Use
The Access Syphilis assay is a paramagnetic particle, chemiluminescent immunoassay for the qualitative detection of total antibodies to Treponema pallidum in human serum and plasma using the Access Immunoassay Systems. It is intended to be used as an aid in the diagnosis of syphilis or in conjunction with a non-treponemal laboratory test and clinical findings to aid in the diagnosis of syphilis infection. The Access Syphilis assay is not intended for blood and tissue donor screening.
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| Features /Characteristics | Candidate DeviceAccess Syphilis | Predicate Device (K153730)ARCHITECT Syphilis |
|---|---|---|
| Reagent Intended Useand ClinicalIndications | Access Immunoassay Systems IFU:The Access Syphilis assay is aparamagnetic particle,chemiluminescent immunoassay for thequalitative detection of total antibodiesto Treponema pallidum in human serumand plasma using the AccessImmunoassay Systems. It is intendedto be used as an aid in the diagnosisof syphilis or in conjunction with anontreponemal laboratory test andclinical findings to aid in thediagnosis of syphilis infection. TheAccess Syphilis assay is not intendedfor blood and tissue donor screening. | The ARCHITECT Syphilis TP assay isa chemiluminescent microparticleimmunoassay (CMIA) for thequalitative detection of antibodies (IgGand IgM) directed against Treponemapallidum (TP) in human serum andplasma. The ARCHITECT SyphilisTP assay is intended to be used asan initial diagnostic test or inconjunction with a nontreponemallaboratory test and clinical findingsto aid in the diagnosis of syphilisinfection.Warning: The ARCHITECT SyphilisTP assay is not intended for use inscreening blood, plasma, or tissuedonors. The effectiveness of theARCHITECT Syphilis TP assay foruse in screening blood, plasma, ortissue donors has not beenestablished. |
| Environment of Use | Health Care Providers requestingsamples to be tested by clinicallaboratory technicians | Same |
| Operating Principle | Chemiluminescent microparticleimmunoassay (CMIA) | Same |
| Antigen sources | Recombinant Treponema pallidumantigens Tp17 and Tp47, andbiotinylated Treponema Tp17 & Tp47antigens | Recombinant TP antigens: TpN15,TpN17 and TpN47 (obtained in E.coli ) |
| Assay Type | Two-step sandwich enzymeimmunoassay | Same |
| Detection Method | Automated, Chemiluminescence | Same |
| Reagent format | Liquid, ready to use | Same |
| Sample Type | Serum and Plasma | Same |
| Features /Characteristics | Candidate DeviceAccess Syphilis | Predicate Device (K153730)ARCHITECT Syphilis |
| CompatibleAnticoagulants | Human Serum:Serum and serum separator tubeHuman Plasma:Lithium HeparinLithium Heparin separator tubeDipotassium (K₂) EDTATripotassium (K₃) EDTASodium CitrateAcid Citrate Dextrose (ACD)Citrate Phosphate Dextrose (CPD)Citrate Phosphate Dextrose withAdenine (CPDA) | Human Serum:Serum and serum separator tubeHuman Plasma:Dipotassium EDTATripotassium EDTALithium heparin plasma separatorLithium heparinSodium heparin |
| Sample Volume | ~45 µL | 30 µL |
| Instrumentation | Access Immunoassay Systems:Access 2 Immunoassay System Dxl 9000 Access Immunoassay Analyzer | ARCHITECT iSystem |
| Test Result Reporting | Reactive, Non-reactive and S/CO | Reactive, Non-reactive and S/CO |
| Time to Result | Access 2 Immunoassay System ~30 minutes Dxl 9000 Access Immunoassay Analyzer ~22 minutes | ~ 29 minutes |
| Reagent Storage andStability | Unopened at 2 to 10°C up to statedexpiration date | Unopened at 2 to 8°C up to statedexpiration date |
| Reagent On-boardStability | 56 Days | 30 days |
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Summary of Studies - Access 2 Immunoassay System
Imprecision
The assay was designed to have within-laboratory imprecision as listed below:
- ·
- · ≤ 10.0% CV at concentrations ≥ 1.00 S/CO
The imprecision of the Access Syphilis assay on the Access 2 Immunoassay Systems was evaluated in a study based on CLSI EP05-A3 guidance.
The within-laboratory intermediate precision study included two test runs per day over 20 test days. A four-member panel of serum (S1-S4) samples and the Access Syphilis QC were assayed in each run (in duplicate). Three lots of Access Syphilis reagent and calibrator were tested on an Access 2 Immunoassay Analyzer for the study. The results are presented below:
| Between Lot | Between Day | Between Run | Within Run | Overall | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample | N | Mean(S/CO) | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV |
| QC1 | 240 | 0.107 | 0.029 | N/A | 0.009 | N/A | 0.007 | N/A | 0.007 | N/A | 0.032 | N/A |
| QC2 | 240 | 1.704 | 0.083 | 4.9% | 0.057 | 3.4% | 0.074 | 4.3% | 0.048 | 2.8% | 0.134 | 7.9% |
| S1 (Low Negative) | 240 | 0.064 | 0.004 | N/A | 0.003 | N/A | 0.004 | N/A | 0.003 | N/A | 0.007 | N/A |
| S2 (High Negative) | 240 | 0.708 | 0.018 | 2.6% | 0.023 | 3.2% | 0.022 | 3.2% | 0.017 | 2.5% | 0.041 | 5.8% |
| S3 (Low Positive) | 240 | 1.819 | 0.116 | 6.4% | 0.061 | 3.4% | 0.051 | 2.8% | 0.039 | 2.2% | 0.146 | 8.0% |
| S4 (Positive) | 240 | 6.721 | 0.491 | 7.3% | 0.216 | 3.2% | 0.203 | 3.0% | 0.179 | 2.7% | 0.601 | 8.9% |
Note: %CV are not meaningful when dose approaches zero. Results are noted as N/A.
Between-Lot Precision
A six-member panel, including serum samples (S1-S4) and two assay controls, were assayed at three clinical sites, using three lots of Access Syphilis reagent to obtain between-lot precision. Each panel member was assayed in replicates of four, twice a day over 5 days. The results are summarized in the following table.
| Within ReagentPack Lot | Between ReagentPack Lot | Total | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Sample | N | Mean(S/CO) | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | |
| QC1 | 360 | 0.10 | 0.01 | N/A | 0.02 | N/A | 0.03 | N/A | |
| QC2 | 360 | 1.56 | 0.09 | 5.5 | 0.01 | 0.9 | 0.09 | 5.5 | |
| S1 (Low Negative) | 360 | 0.06 | 0.01 | N/A | 0.00 | N/A | 0.01 | N/A | |
| S2 (High Negative) | 360 | 0.75 | 0.03 | 4.3 | 0.01 | 1.9 | 0.03 | 4.7 | |
| S3 (Low Positive) | 360 | 1.89 | 0.09 | 4.5 | 0.06 | 3.1 | 0.10 | 5.5 | |
| S4 (Positive) | 360 | 7.19 | 0.30 | 4.2 | 0.25 | 3.5 | 0.39 | 5.4 |
Note: %CV are not meaningful when dose approaches zero. Results are noted as N/A.
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Reproducibility
A 5-day between lab reproducibility study was performed on the Access 2 Immunoassay Systems based on CLSI EP05- A3 quidance. A six-member panel, including serum samples (S1-S4) and two assay controls, were assayed at three clinical sites, using three lots of Access Syphilis reagent on three instruments. Each panel member was assayed in replicates of four at two separate times per day. The results are summarized in the following table.
| Repeatability(Within Run) | Between Run | Between Day | Between Lot | Between Site | Reproducibility | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample | N | Mean(S/CO) | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | |
| QC1 | 360 | 0.10 | 0.004 | N/A | 0.005 | N/A | 0.006 | N/A | 0.025 | N/A | 0.005 | N/A | 0.027 | N/A | |
| QC2 | 360 | 1.56 | 0.043 | 2.8 | 0.058 | 3.7 | 0.016 | 1.0 | 0.010 | 0.6 | 0.054 | 3.4% | 0.092 | 5.9 | |
| S1 (LowNegative) | 360 | 0.06 | 0.003 | N/A | 0.003 | N/A | 0.003 | N/A | 0.005 | N/A | 0.005 | N/A | 0.009 | N/A | |
| S2 (HighNegative) | 360 | 0.75 | 0.019 | 2.6 | 0.018 | 2.4 | 0.018 | 2.5 | 0.013 | 1.8 | 0.005 | 0.6% | 0.035 | 4.7 | |
| S3 (LowPositive) | 360 | 1.89 | 0.042 | 2.2 | 0.065 | 3.5 | 0.037 | 2.0 | 0.058 | 3.1 | 0.000 | N/A | 0.104 | 5.5 | |
| S4(Positive) | 360 | 7.19 | 0.223 | 3.1 | 0.197 | 2.7 | 0.000 | N/A | 0.247 | 3.4 | 0.068 | 0.9% | 0.393 | 5.5 |
Note: %CV are not meaningful when dose approaches zero. Results are noted as N/A.
INTERFERING SUBSTANCES
The Access Syphilis assay was evaluated for interference consistent with CLSI document EP07 3rd Edition. Testing was performed using two nonreactive (one low negative and one high negative) and two reactive (one low positive and one positive) samples. Of the endogenous compounds tested, none were found to cause interference at the highest test concentrations indicated in the following table.
| Potential Interferent | Highest Concentration |
|---|---|
| Hemoglobin | 1,000 mg/dL |
| Total Protein | 15 g/dL |
| Bilirubin - conjugated | 40 mg/dL |
| Bilirubin - unconjugated | 40 mg/dL |
| Triolein | 36 g/L |
| Biotin | 0.351 mg/dL |
| Gamma globulin | 47.5 g/L* |
*Interference was noted at a concentration of 60 g/L. A dose effect study was conducted, with no interference observed ≤47.5 g(L.
The following pharmaceutical substances were also evaluated and no interference with the assay was observed: acetylsalicylic acid (aspirin), acetaminophen (paracetamol), ibuprofen, azithromycin, ceftriaxone sodium, doxycycline hyclate.
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Cross Reactivity
Cross-reactivity was evaluated by testing samples for potentially cross-reacting conditions. No crossreactivity was observed. The results are summarized in the following table.
| Category | Number of SamplesTested | Number ofReactive Samples | Number ofNonreactiveSamples |
|---|---|---|---|
| Pregnant multipara | 14 | 0 | 14 |
| Hemodialysis patients | 10 | 0 | 10 |
| Transplant patients | 10 | 0 | 10 |
| Rheumatoid Factor (RF) | 10 | 0 | 10 |
| Human Anti-mouse Antibody (HAMA) | 10 | 0 | 10 |
| Anti-Nuclear Antibody (ANA) | 10 | 0 | 10 |
| Lyme Disease (Borrelia garinii, Borrelia afzelii& Borrelia burgdorferi s.s.) | 10 | 0 | 10 |
| Toxoplasma gondii IgG | 5 | 0 | 5 |
| Toxoplasma gondii IgM | 5 | 0 | 5 |
| Epstein Barr Virus (EBV) IgG | 10 | 0 | 10 |
| Epstein Barr Virus (EBV) IgM | 10 | 0 | 10 |
| Leptospirosis | 10 | 0 | 10 |
| Systemic Lupus Erythemateous (SLE) | 10 | 0 | 10 |
| Hepatitis A Virus (HAV) Total Ab | 5 | 0 | 5 |
| Hepatitis A Virus (HAV) IgM | 5 | 0 | 5 |
| Hepatitis B Virus (HBV) - HBs Ag positive | 10 | 0 | 10 |
| Hepatitis B Virus (HBV) -anti-HBs positive | 22 | 0 | 22 |
| Hepatitis B Virus (HBV) - HBc IgM positive | 9 | 0 | 9 |
| Hepatitis B Virus (HBV) - Anti HBc total positive | 20 | 0 | 20 |
| Hepatitis C Virus (HCV) | 10 | 0 | 10 |
| HTLV-1 | 10 | 0 | 10 |
| HTLV-2 | 13 | 0 | 13 |
| Human Immunodeficiency Virus (HIV)-1 | 8 | 0 | 8 |
| Human Immunodeficiency Virus (HIV)-2 | 9 | 0 | 9 |
| Herpes Simplex Virus (HSV) 1& 2 IgM | 15 | 0 | 15 |
| Herpes Simplex Virus (HSV) 1 IgG | 10 | 0 | 10 |
| Herpes Simplex Virus (HSV) 2 IgG | 2 | 0 | 2 |
| Cytomegalovirus (CMV) IgG | 5 | 0 | 5 |
| Cytomegalovirus (CMV) IgM | 5 | 0 | 5 |
| Rubella IgG | 5 | 0 | 5 |
| Rubella IgM | 10 | 0 | 10 |
| Anti-Escherichia coli (E.coli) | 10 | 0 | 10 |
| Multiple myeloma | 10 | 0 | 10 |
| Flu vaccinated patients | 10 | 0 | 10 |
| Anti-Phospholipid | 10 | 0 | 10 |
| TOTAL | 337 | 0 | 337 |
{10}------------------------------------------------
Clinical Performance Evaluation - Access 2 Immunoassay System
A total of 1,104 prospectively collected specimens from the intended use population were tested using the Access Syphilis assay. 704 (63.8%) were female and 400 (36.2%) were male, with an age range of 12 to > 89 years. The Access Syphilis assay was reactive in 214 (19.4%) of specimens collected from the intended use population.
| Age Range(Years) | Gender | Total | Access Syphilis Assay | |
|---|---|---|---|---|
| Reactive N(%) | Nonreactive N(%) | |||
| 12-20 | Male | 7 | 0 (0.0) | 7 (100.0) |
| 12-20 | Female | 48 | 2 (4.2) | 46 (95.8) |
| 21-30 | Male | 44 | 9 (20.4) | 35 (79.6) |
| 21-30 | Female | 256 | 8 (3.1) | 248 (96.9) |
| 31-40 | Male | 72 | 36 (50.0) | 36 (50.0) |
| 31-40 | Female | 211 | 12 (5.7) | 199 (94.3) |
| 41-50 | Male | 87 | 38 (43.7) | 49 (56.3) |
| 41-50 | Female | 68 | 9 (13.2) | 59 (86.8) |
| 51-60 | Male | 123 | 54 (43.9) | 69 (56.1) |
| 51-60 | Female | 68 | 17 (25.0) | 51 (75.0) |
| 61-70 | Male | 54 | 16 (29.6) | 38 (70.4) |
| 61-70 | Female | 38 | 10 (26.3) | 28 (73.7) |
| 71-89* | Male | 13 | 2 (15.4) | 11 (84.6) |
| 71-89* | Female | 15 | 1 (6.7) | 14 (93.3) |
| Total | 1,104 | 214 (19.4) | 890 (80.6) |
Distribution of the Access Syphilis Reactive results in the intended use population by age and gender
- NOTE: One (1) subject was > 89 years
Clinical Performance
A multicenter study was conducted to evaluate the clinical performance of the Access Syphilis assay. A total of 1,910 specimens were included in this study with 1,104 prospectively collected specimens from the intended use population, 402 retrospective specimens from patients, 204 prospectively collected specimens from apparently healthy individuals, 150 retrospecimens from patients with medically diagnosed syphilis, and 50 retrospective specimens from individuals at high-risk of sexually transmitted disease.
The specimens were tested at three sites in a randomized and blinded fashion (all cohorts), using the Access Syphilis assay, and a final comparator result was obtained using a composite testing algorithm consisting of the following FDA-approved assays: the predicate treponemal immunoassay, a nontreponemal assay (RPR - Rapid Plasma Reagin), and a second treponemal assay (TPPA -Treponema Pallidum Particle Agglutination).
{11}------------------------------------------------
Clinical Performance in Intended Use Population
A total of 1,104 specimens from the intended use population were prospectively collected and tested with Access Syphilis and the composite testing algorithm described above. The study included specimens from 399 patients sent for syphilis testing, 405 pregnant women and 300 HIV positive patients.
| PredicateTreponemalImmunoassay | RPR | TPPA | FinalComparatorResult | Access SyphilisResult | N |
|---|---|---|---|---|---|
| - | - | NA | - | - | 878 |
| - | + | - | - | - | 5 |
| - | + | + | + | - | 0 |
| + | - | - | - | - | 7 |
| + | - | + | + | - | 0 |
| + | + | NA | + | - | 0 |
| - | + | INC | - | - | 0 |
| + | + | NA | + | + | 79 |
| + | - | + | + | + | 104 |
| + | - | - | - | + | 12 |
| - | + | + | + | + | 0 |
| - | + | - | - | + | 0 |
| - | - | - | - | + | 13 |
| - | - | + | - | + | 5 |
| + | - | INC | + | + | 1 |
| Total | 1,104 |
Summary of the Serological Profile for all Prospectively Collected Specimens from the Intended Use Population
- = Reactive; - = Nonreactive; NA = not performed; INC = Inconclusive
The overall positive percent agreement was 100% (184/184) with a 95% confidence interval of 98.0 to 100% and the overall negative percent agreement was 96.7% (890/920) with a 95% confidence interval of 95.4 to 97.7%
Percent Agreement for Intended Use Subpopulations
| Positive Percent Agreement | Negative Percent Agreement | |||
|---|---|---|---|---|
| Subpopulation | n/N | %(95% CI) | n/N | %(95% CI) |
| Routine Syphilis Testing | 60/60 | 100(94.0 - 100) | 338/3391 | 99.7(98.4 - 100) |
| Pregnant Women | 6/6 | 100(61.0 - 100) | 398/399 | 99.8(98.6 - 100) |
| HIV Positive Patients | 118/118 | 100(96.9 - 100) | 154/1822 | 84.6(78.7 - 89.1) |
| Total | 184/184 | 100(98.0 - 100) | 890/920 | 96.7(95.4 - 97.7) |
^ One (1) specimen from the routine syphilis testine by an FDA-cleared treponemal immunoassay and nonreactive by RPR and TPPA.
²Twenty-five (25) out of twenty-eight (28) discordants were found to be reactive using an additional FDA-cleared electrochemiluminescent immunoassay. Eleven (11) of these were also reactive by the predicate treponemal immunoassay.
{12}------------------------------------------------
Clinical Performance in Retrospective Specimens
A cohort of 402 retrospective specimens were included in the study, of which 22 were from pregnant females.
| PredicateTreponemalImmunoassay | RPR | TPPA | FinalComparatorResult | Access SyphilisResult | N |
|---|---|---|---|---|---|
| - | - | NA | - | - | 1 |
| - | + | - | - | - | 0 |
| - | + | + | + | - | 0 |
| + | - | - | - | - | 0 |
| + | - | + | + | - | 0 |
| + | + | NA | + | - | 0 |
| - | + | INC | - | - | 0 |
| + | + | NA | + | + | 324 |
| + | - | + | + | + | 74 |
| + | - | - | - | + | 3 |
| - | + | + | + | + | 0 |
| - | + | - | - | + | 0 |
| - | - | - | - | + | 0 |
| - | - | + | - | + | 0 |
| + | - | INC | + | + | 0 |
| Total | 402 |
Summary of the Serological Profile for Retrospective Specimens
- = Reactive; - = Nonreactive; NA = not performed; INC = Inconclusive
Comparison between the Access Syphilis Results and the Final Comparator Results in Retrospective Specimens
| Retrospective Specimens | Final Comparator Result | |||
|---|---|---|---|---|
| Reactive | Nonreactive | Total | ||
| Access SyphilisResult | Reactive | 398 | 31 | 401 |
| Nonreactive | 0 | 1 | 1 | |
| Total | 398 | 4 | 402 |
1Three (3) specimens were reactive by treponemal immunoassay and nonreactive by RPR and TPPA
The positive percent agreement was 100% (398/398) with a 95% confidence interval of 99.0 to 100% and the negative percent agreement was 25.0% (1/4) with a 95% confidence interval of 4.6 to 69.9%.
{13}------------------------------------------------
Clinical Performance in Apparently Healthy Individuals
Of the total 1,910 specimens in the study, 204 were prospectively collected from apparently healthy individuals. Results of the Access Syphilis assay are shown below:
| Access Syphilis Result | ||
|---|---|---|
| Apparently Healthy Individuals | Reactive (%) | Nonreactive (%) |
| 18 (8.8) | 186 (91.2) |
Clinical Performance in Medically Diagnosed Patients
A total of 150 retrospective specimens from patients with medically diagnosed syphilis (primary, secondary, and latent stages) were included in the study. Results of the Access Syphilis assay are shown in the following table:
| Syphilis Stage | Treatment Status | N | Access Syphilis | |
|---|---|---|---|---|
| Reactive | Nonreactive | |||
| Primary | Untreated | 49 | 49 | 0 |
| Primary | Treated | 27 | 26 | 11 |
| Secondary | Untreated | 13 | 13 | 0 |
| Secondary | Treated | 23 | 23 | 0 |
| Latent | Untreated | 13 | 7 | 61 |
| Latent | Treated | 25 | 25 | 0 |
1 These seven (7) specimens also tested nonreactive with an FDA-cleared treponemal immunoassay.
Clinical Performance in Pregnant Females
A total of 427 pregnant female specimens were included in the study, with 405 prospectively collected and 22 retrospectively collected specimens. Percent Agreement Between Access Syphilis and the Final Comparator Result by Trimester
| Trimester | N | Positive PercentAgreement% (x/n) | 95%ConfidenceInterval (%) | Negative PercentAgreement% (x/n) | 95%ConfidenceInterval (%) |
|---|---|---|---|---|---|
| Prospectively Collected | |||||
| First Trimester | 60 | 100 (1/1) | 20.7 - 100 | 100 (59/59) | 93.9 - 100 |
| Second Trimester | 38 | 100 (1/1) | 20.7 - 100 | 100 (37/37) | 90.6 - 100 |
| Third Trimester | 307 | 100 (4/4) | 51.0 - 100 | 99.7 (302/303) | 98.2 - 99.9 |
| Unknown Trimester | 0 | NA | NA | NA | NA |
| Total | 405 | 100 (6/6) | 61.0 - 100 | 99.8 (398/399) | 98.6 - 100 |
| Retrospective Specimens | |||||
| First Trimester | 6 | 100 (6/6) | 61.0 - 100 | NA (0/0) | NA |
| Second Trimester | 9 | 100 (9/9) | 70.1 - 100 | NA (0/0) | NA |
| Third Trimester | 6 | 100 (5/5) | 56.6 - 100 | 100 (1/1) | 20.7 - 100 |
| Unknown Trimester | 1 | NA (0/0) | 20.7 - 100 | 0 (0/1) | 0 - 79.4 |
| Total | 22 | 100 (20/20) | 83.9 - 100 | 50.0 (1/2) | 9.5 - 90.6 |
NA - Not applicable
{14}------------------------------------------------
Clinical Performance in High-Risk Individuals
Of the total 1,910 specimens in the study, 50 retrospective specimens were from individuals at highrisk of sexually transmitted disease.
Comparison Between the Access Syphilis Results and the Final Comparator Results in High-Risk Individuals
| High-Risk Individuals | Final Comparator Result | |||
|---|---|---|---|---|
| Reactive | Nonreactive | Total | ||
| Access SyphilisResult | Reactive | 20 | 61 | 26 |
| Nonreactive | 0 | 24 | 24 | |
| Total | 20 | 30 | 50 |
1 One (1) specimen was reactive by treponemal immunoassay and nonreactive by RPR and TPPA
The percent agreement was 100% (20/20) with a 95% confidence interval of 83.9 to 100% and the negative percent agreement was 80.0% (24/30) with a 95% confidence interval of 62.7 to 90.5%.
{15}------------------------------------------------
Summary of Studies – Dxl 9000 Immunoassay Analyzer
Imprecision
The assay was designed to have within-laboratory imprecision as listed below:
- ·
- · ≤ 10.0% CV at concentrations ≥ 1.00 S/CO
The imprecision of the Access Syphilis assay on the Dxl 9000 Access Immunoassay Analyzer was evaluated in a study based on CLSI EP05-A3 guidance.
The within-laboratory intermediate precision study included two test runs per day over 20 test days. A four-member panel of serum (S1-S4) samples and the Access Syphilis QC were assayed in each run (in duplicate). Three lots of Access Syphilis reagent and calibrator were tested on two Dxl 9000 Access Immunoassay Analyzers for the study, with each lot tested on one instrument. The results are presented below:
| Between Lot &Instrument | Between Day | Between Run | Within Run | Overall | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample | N | Mean(S/CO) | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV |
| QC1 | 238 | 0.166 | 0.064 | N/A | 0.007 | N/A | 0.007 | N/A | 0.008 | N/A | 0.065 | N/A |
| QC2 | 238 | 1.786 | 0.082 | 4.6% | 0.059 | 3.3% | 0.088 | 4.9% | 0.041 | 2.3% | 0.140 | 7.8% |
| S1 (LowNegative) | 240 | 0.078 | 0.018 | N/A | 0.003 | N/A | 0.003 | N/A | 0.005 | N/A | 0.019 | N/A |
| S2 (HighNegative) | 239 | 0.779 | 0.065 | 8.4% | 0.021 | 2.8% | 0.023 | 3.0% | 0.019 | 2.4% | 0.075 | 9.6% |
| S3 (LowPositive) | 240 | 1.994 | 0.078 | 3.9% | 0.048 | 2.4% | 0.072 | 3.6% | 0.046 | 2.3% | 0.125 | 6.3% |
| S4 (Positive) | 240 | 7.598 | 0.294 | 3.9% | 0.241 | 3.2% | 0.240 | 3.2% | 0.163 | 2.1% | 0.478 | 6.3% |
Note: %CV are not meaningful when dose approaches zero. Results are noted as N/A.
{16}------------------------------------------------
Between-Lot Precision
A six-member panel, including serum samples (S1-S4) and two assay controls, were assayed at three clinical sites, using three lots of Access Syphilis reagent to obtain between-lot precision. Each panel member was assayed in replicates of four, twice a day over 5 days. The results are summarized in the following table.
| Within ReagentPack Lot | Between ReagentPack Lot | Total | ||||||
|---|---|---|---|---|---|---|---|---|
| Sample | N | Mean(S/CO) | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV |
| QC1 | 360 | 0.10 | 0.013 | N/A | 0.033 | N/A | 0.035 | N/A |
| QC2 | 360 | 1.59 | 0.087 | 5.5 | 0.005 | 0.3 | 0.087 | 5.5 |
| S1 (Low Negative) | 360 | 0.05 | 0.007 | N/A | 0.007 | N/A | 0.010 | N/A |
| S2 (High Negative) | 360 | 0.75 | 0.045 | 6.0 | 0.019 | 2.6 | 0.048 | 6.5 |
| S3 (Low Positive) | 360 | 1.94 | 0.109 | 5.6 | 0.056 | 2.9 | 0.122 | 6.3 |
| S4 (Positive) | 360 | 7.48 | 0.537 | 7.2 | 0.303 | 4.0 | 0.616 | 8.2 |
Note: %CV are not meaningful when dose approaches zero. Results are noted as N/A.
Reproducibility
A 5-day between lab reproducibility study was performed on the Dxl 9000 Access Immunoassay analyzer based on CLSI EP05-A3 guidance14. A six-member panel, including serum samples (S1-S4) and two assay controls, were assayed at three clinical sites, using three lots of Access Syphilis reagent on three instruments. Each panel member was assayed in replicates of four at two separate times per day. The results are summarized in the following table.
| Repeatability(Within Run) | Between Run | Between Day | Between Lot | Between Site | Reproducibility | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sample | N | Mean(S/CO) | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV | SD(S/CO) | %CV |
| QC1 | 360 | 0.10 | 0.005 | N/A | 0.003 | N/A | 0.009 | N/A | 0.033 | N/A | 0.010 | N/A | 0.036 | N/A |
| QC2 | 360 | 1.59 | 0.037 | 2.3 | 0.050 | 3.2 | 0.059 | 3.7 | 0.000 | N/A | 0.019 | 1.2 | 0.088 | 5.5 |
| S1 (LowNegative) | 360 | 0.05 | 0.003 | N/A | 0.001 | N/A | 0.004 | N/A | 0.007 | N/A | 0.005 | N/A | 0.010 | N/A |
| S2 (HighNegative) | 360 | 0.75 | 0.017 | 2.3 | 0.018 | 2.4 | 0.029 | 3.8 | 0.018 | 2.4 | 0.030 | 4.0 | 0.052 | 6.9 |
| S3 (LowPositive) | 360 | 1.94 | 0.044 | 2.3 | 0.060 | 3.1 | 0.070 | 3.6 | 0.053 | 2.7 | 0.052 | 2.7 | 0.126 | 6.5 |
| S4(Positive) | 360 | 7.48 | 0.271 | 3.6 | 0.271 | 3.6 | 0.213 | 2.8 | 0.297 | 4.0 | 0.387 | 5.2 | 0.655 | 8.8 |
Note: %CV are not meaningful when dose approaches zero. Results are noted as N/A.
{17}------------------------------------------------
Interfering Substances
The Access Syphilis assay was evaluated for interference consistent with CLSI document EP07 3rd Edition. Testing was performed using two nonreactive (one low negative and one high negative) and two reactive (one low positive) samples. Of the endogenous compounds tested, none were found to cause interference at the highest test concentrations indicated in the following table.
| Potential Interferent | Highest Concentration |
|---|---|
| Hemoglobin | 1,000 mg/dL |
| Total Protein | 15 g/dL |
| Bilirubin - conjugated | 40 mg/dL |
| Bilirubin - unconjugated | 40 mg/dL |
| Triolein | 36 g/L |
| Biotin | 0.351 mg/dL |
| Gamma globulin | 47.5 g/L* |
*Interference was noted at a concentration of 60 g/L. A dose effect study was conducted, with no interference observed s47.5 g(L.
The following pharmaceutical substances were also evaluated and no interference with the assay was observed: acetylsalicylic acid (aspirin), acetaminophen (paracetamol), ibuprofen, azithromycin, ceftriaxone sodium, doxycycline hyclate.
{18}------------------------------------------------
Cross Reactivity
Cross-reactivity was evaluated by testing samples for potentially cross-reacting conditions. No cross-reactivity was observed. The results are summarized in the following table.
| Category | Number of SamplesTested | Number ofReactive Samples | Number ofNonreactive Samples |
|---|---|---|---|
| Pregnant multipara | 14 | 0 | 14 |
| Hemodialysis patients | 10 | 0 | 10 |
| Transplant patients | 10 | 0 | 10 |
| Rheumatoid Factor (RF) | 10 | 0 | 10 |
| Human Anti-mouse Antibody (HAMA) | 10 | 0 | 10 |
| Anti-Nuclear Antibody (ANA) | 10 | 0 | 10 |
| Lyme Disease (Borrelia garinii, Borreliaafzelii & Borrelia burgdorferi s.s.) | 10 | 0 | 10 |
| Toxoplasma gondii IgG | 5 | 0 | 5 |
| Toxoplasma gondii IgM | 5 | 0 | 5 |
| Epstein Barr Virus (EBV) IgG | 10 | 0 | 10 |
| Epstein Barr Virus (EBV) IgM | 10 | 0 | 10 |
| Leptospirosis | 10 | 0 | 10 |
| Systemic Lupus Erythematous (SLE) | 10 | 0 | 10 |
| Hepatitis A Virus (HAV) Total Ab | 5 | 0 | 5 |
| Hepatitis A Virus (HAV) IgM | 5 | 0 | 5 |
| Hepatitis B Virus (HBV) - HBs Ag positive | 10 | 0 | 10 |
| Hepatitis B Virus (HBV) -anti-HBs positive | 22 | 0 | 22 |
| Hepatitis B Virus (HBV) - HBc IgM positive | 9 | 0 | 9 |
| Hepatitis B Virus (HBV) - Anti HBc totalpositive | 20 | 0 | 20 |
| Hepatitis C Virus (HCV) | 10 | 0 | 10 |
| HTLV-1 | 10 | 0 | 10 |
| HTLV-2 | 13 | 0 | 13 |
| Human Immunodeficiency Virus (HIV)-1 | 8 | 0 | 8 |
| Human Immunodeficiency Virus (HIV)-2 | 9 | 0 | 9 |
| Herpes Simplex Virus (HSV) 1& 2 IgM | 15 | 0 | 15 |
| Herpes Simplex Virus (HSV) 1 IgG | 10 | 0 | 10 |
| Herpes Simplex Virus (HSV) 2 IgG | 2 | 0 | 2 |
| Cytomegalovirus (CMV) IgG | 5 | 0 | 5 |
| Cytomegalovirus (CMV) IgM | 5 | 0 | 5 |
| Rubella IgG | 5 | 0 | 5 |
| Rubella IgM | 10 | 0 | 10 |
| Anti-Escherichia coli (E.coli) | 10 | 0 | 10 |
| Multiple myeloma | 10 | 0 | 10 |
| Flu vaccinated patients | 10 | 0 | 10 |
| Anti-Phospholipid | 10 | 0 | 10 |
| TOTAL | 337 | 0 | 337 |
{19}------------------------------------------------
Clinical Performance Evaluation - Dxl 9000 Immunoassay Analyzer
A total of 1,104 prospectively collected specimens from the intended use population were tested using the Access Syphilis assay. 704 (63.8%) were female and 400 (36.2%) were male, with an age range of 12 to > 89 years. The Access Syphilis assay was reactive in 214 (19.4%) of specimens collected from the intended use population.
| Age Range(Years) | Gender | Total | Access Syphilis Assay | |
|---|---|---|---|---|
| ReactiveN (%) | NonreactiveN (%) | |||
| 12-20 | Male | 7 | 0 (0.0) | 7 (100.0) |
| Female | 48 | 2 (4.2) | 46 (95.8) | |
| 21-30 | Male | 44 | 9 (20.4) | 35 (79.6) |
| Female | 256 | 8 (3.1) | 248 (96.9) | |
| 31-40 | Male | 72 | 36 (50.0) | 36 (50.0) |
| Female | 211 | 12 (5.7) | 199 (94.3) | |
| 41-50 | Male | 87 | 38 (43.7) | 49 (56.3) |
| Female | 68 | 9 (13.2) | 59 (86.8) | |
| 51-60 | Male | 123 | 54 (43.9) | 69 (56.1) |
| Female | 68 | 17 (25.0) | 51 (75.0) | |
| 61-70 | Male | 54 | 16 (29.6) | 38 (70.4) |
| Female | 38 | 10 (26.3) | 28 (73.7) | |
| 71-89* | Male | 13 | 2 (15.4) | 11 (84.6) |
| Female | 15 | 1 (6.7) | 14 (93.3) | |
| Total | 1,104 | 214 (19.4) | 890 (80.6) |
Distribution of the Access Syphilis Reactive and Nonreactive Results in the Intended Use Population by Age and Gender
- NOTE: One (1) subject was > 89 years
Clinical Performance
A multicenter study was conducted to evaluate the clinical performance of the Access Syphilis assay. A total of 1,910 specimens were included in this study with 1,104 prospectively collected specimens from the intended use population, 402 retrospective specimens , 204 prospectively collected specimens from apparently healthy individuals, 150 retrospective specimens with medically diagnosed syphilis, and 50 retrospective specimens from individuals at high-risk of sexually transmitted disease.
The specimens were tested at three sites in a randomized and blinded fashion (all cohorts), using the Access Syphilis assay, and a final comparator result was obtained using a composite testing algorithm consisting of the following FDA-approved assays: the predicate treponemal immunoassay, a nontreponemal assay (RPR - Rapid Plasma Reagin), and a second treponemal assay (TPPA -Treponema Pallidum Particle Agglutination).
Clinical Performance in Intended Use Population
A total of 1,104 specimens from the intended use population were prospectively collected with Access Syphilis and the composite testing algorithm described above. The study included specimens from 399 patients sent for syphilis testing, 405 pregnant women and 300 HIV positive patients.
{20}------------------------------------------------
| PredicateTreponemalImmunoassay | RPR | TPPA | FinalComparatorResult | Access SyphilisResult | N |
|---|---|---|---|---|---|
| - | - | NA | - | - | 878 |
| - | + | - | - | - | 5 |
| - | + | + | + | - | 0 |
| + | - | - | - | - | 7 |
| + | - | + | + | - | 0 |
| + | + | NA | + | - | 0 |
| - | + | INC | - | - | 0 |
| + | + | NA | + | + | 79 |
| + | - | + | + | + | 104 |
| + | - | - | - | + | 12 |
| - | + | + | + | + | 0 |
| - | + | - | - | + | 0 |
| - | - | - | - | + | 13 |
| - | - | + | - | + | 5 |
| + | - | INC | + | + | 1 |
| Total | 1,104 |
Summary of the Serological Profile for all Prospectively Collected Specimens from the Intended Use Population
- = Reactive; - = Nonreactive; NA = not performed; INC = Inconclusive
The overall positive percent agreement was 100% (184/184) with a 95% confidence interval of 98.0 to 100% and the overall negative percent agreement was 96.7% (890/920) with a 95% confidence interval of 95.4 to 97.7%.
Percent Agreement for Intended Use Subpopulations
| Subpopulation | Positive Percent Agreement | Negative Percent Agreement | ||
|---|---|---|---|---|
| n/N | %(95% CI) | n/N | %(95% CI) | |
| Routine Syphilis Testing | 60/60 | 100(94.0 - 100) | 338/3391 | 99.7(98.4 - 100) |
| Pregnant Women | 6/6 | 100(61.0 - 100) | 398/399 | 99.8(98.6 - 100) |
| HIV Positive Patients | 118/118 | 100(96.9 - 100) | 154/1822 | 84.6(78.7 - 89.1) |
| Total | 184/184 | 100(98.0 - 100) | 890/920 | 96.7(95.4 - 97.7) |
1 One (1) specimen from the routine syphilis testing cohort was reactive by an FDA-cleared treponemal immunoassay and nonreactive by RPR and TPPA
²Twenty-five (25) out of twenty-eight (28) discordants were found to be reactive using an additional FDA-cleared electrochemiluminescent immunoassay. Eleven (11) of these were also reactive by the predicate treponemal immunoassay.
Clinical Performance in Retrospective Specimens
A cohort of 402 retrospective specimens from patients were included in the study, of which 22 were from pregnant females.
{21}------------------------------------------------
| PredicateTreponemalImmunoassay | RPR | TPPA | FinalComparatorResult | Access SyphilisResult | N |
|---|---|---|---|---|---|
| - | - | NA | - | - | 1 |
| - | + | - | - | - | 0 |
| - | + | + | + | - | 0 |
| + | - | - | - | - | 0 |
| + | - | + | + | - | 0 |
| + | + | NA | + | - | 0 |
| - | + | INC | - | - | 0 |
| + | + | NA | + | + | 324 |
| + | - | + | + | + | 74 |
| + | - | - | - | + | 3 |
| - | + | + | + | + | 0 |
| - | + | - | - | + | 0 |
| - | - | - | - | + | 0 |
| - | - | + | - | + | 0 |
| + | - | INC | + | + | 0 |
| Total I | 402 |
Summary of the Serological Profile for Retrospective Specimens
- = Reactive; - = Nonreactive; NA = not performed; INC = Inconclusive
Comparison Between the Access Syphilis Results and the Final Comparator Results in Retrospective Specimens
| Retrospective Specimens | Final Comparator Result | |||
|---|---|---|---|---|
| Reactive | Nonreactive | Total | ||
| Access SyphilisResult | Reactive | 398 | 3 1 | 401 |
| Nonreactive | 0 | 1 | 1 | |
| Total | 398 | 4 | 402 |
1Three (3) specimens were reactive by treponemal immunoassay and nonreactive by RPR and TPPA
The positive percent agreement was 100% (398/398) with a 95% confidence interval of 99.0 to 100% and the negative percent agreement was 25.0% (1/4) with a 95% confidence interval of 4.6 to 69.9%.
Clinical Performance in Apparently Healthy Individuals
Of the total 1,910 specimens in the study, 204 were prospectively collected from apparently healthy individuals. Results of the Access Syphilis assay are shown below:
| Access Syphilis Result | ||
|---|---|---|
| Apparently Healthy Individuals | Reactive (%) | Nonreactive (%) |
| 18 (8.8) | 186 (91.2) |
{22}------------------------------------------------
Clinical Performance in Medically Diagnosed Patients
A total of 150 retrospective specimens from patients with medically diagnosed syphilis (primary, secondary, and latent stages) were included in the study. Results of the Access Syphilis assay are shown in the following table:
| Syphilis Stage | Treatment Status | N | Access Syphilis | |
|---|---|---|---|---|
| Reactive | Nonreactive | |||
| Primary | Untreated | 49 | 49 | 0 |
| Primary | Treated | 27 | 26 | 11 |
| Secondary | Untreated | 13 | 13 | 0 |
| Secondary | Treated | 23 | 23 | 0 |
| Latent | Untreated | 13 | 7 | 61 |
| Latent | Treated | 25 | 25 | 0 |
1 These seven (7) specimens also tested nonreactive with an FDA-cleared treponemal immunoassay.
Clinical Performance in Pregnant Females
A total of 427 pregnant female specimens were included in the study, with 405 prospectively collected and 22 retrospective specimens.
Percent Agreement Between Access Syphilis and the Final Comparator Result by Trimester
| Trimester | N | Positive PercentAgreement% (x/n) | 95%Confidence Interval(%) | Negative PercentAgreement% (x/n) | 95%ConfidenceInterval (%) | |
|---|---|---|---|---|---|---|
| Prospectively Collected | ||||||
| First Trimester | 60 | 100 (1/1) | 20.7 - 100 | 100 (59/59) | 93.9 - 100 | |
| Second Trimester | 38 | 100 (1/1) | 20.7 - 100 | 100 (37/37) | 90.6 - 100 | |
| Third Trimester | 307 | 100 (4/4) | 51.0 - 100 | 99.7 (302/303) | 98.2 - 99.9 | |
| Unknown Trimester | 0 | NA | NA | NA | NA | |
| Total | 405 | 100 (6/6) | 61.0 - 100 | 99.8 (398/399) | 98.6 - 100 | |
| Retrospective Specimens | ||||||
| First Trimester | 6 | 100 (6/6) | 61.0 - 100 | NA (0/0) | NA | |
| Second Trimester | 9 | 100 (9/9) | 70.1 - 100 | NA (0/0) | NA | |
| Third Trimester | 6 | 100 (5/5) | 56.6 - 100 | 100 (1/1) | 20.7 - 100 | |
| Unknown Trimester | 1 | NA (0/0) | 20.7 - 100 | 0 (0/1) | 0 - 79.4 | |
| Total | 22 | 100 (20/20) | 83.9 - 100 | 50.0 (1/2) | 9.5 - 90.6 |
NA - Not applicable
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Clinical Performance in High-Risk Individuals
Of the total 1,910 specimens in the study, 50 retrospective specimens were from individuals at high-risk of sexually transmitted disease.
Comparison Between the Access Syphilis Results and the Final Comparator Results in High-Risk Individuals
| Final Comparator Result | ||||
|---|---|---|---|---|
| High-Risk Individuals | Reactive | Nonreactive | Total | |
| Reactive | 20 | 61 | 26 | |
| Access Syphilis Result | Nonreactive | 0 | 24 | 24 |
| Total | 20 | 30 | 50 |
1 One (1) specimen was reactive by treponemal immunoassay and nonreactive by RPR and TPPA
The positive percent agreement was 100% (20/20) with a 95% confidence interval of 83.9 to 100% and the negative percent agreement was 80.0% (24/30) with a 95% confidence interval of 62.7 to 90.5%.
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Substantial Equivalence Comparison Conclusion
Beckman Coulter's Access Syphilis is substantially equivalent to the ARCHITECT Syphilis TP Reagent as demonstrated through the information and data provided in this submission. The performance and clinical testing presented in this submission provides evidence that the device is safe and effective for its intended use.
§ 866.3830
Treponema pallidum treponemal test reagents.(a)
Identification. Treponema pallidum treponemal test reagents are devices that consist of the antigens, antisera and all control reagents (standardized reagents with which test results are compared) which are derived from treponemal sources and that are used in the fluorescent treponemal antibody absorption test (FTA-ABS), theTreponema pallidum immobilization test (T.P.I.), and other treponemal tests used to identify antibodies toTreponema pallidum directly from infecting treponemal organisms in serum. The identification aids in the diagnosis of syphilis caused by bacteria belonging to the genusTreponema and provides epidemiological information on syphilis.(b)
Classification. Class II (performance standards).