(56 days)
The Varelisa Cardiolipin IgG Antibodies EIA kit is designed for the semiquantitative and qualitative determination of IgG antibodies against cardiolipin in serum or plasma to aid in the diagnosis of antiphospholipid syndrome (APS) and to evaluate the thrombotic risk in patients with systemic lupus erythematosus (SLE).
The Varelisa Cardiolipin IgG Antibodies is an indirect noncompetitive enzyme immunoassay for the semiquantitative and qualitative determination of IgG antibodies against cardiolipin in human serum or plasma. The wells of a microplate are coated with bovine cardiolipin antigen. Antibodies specific for cardiolipin present in the patient sample bind to the antigen. In a second step an enzyme labeled second antibody (Conjugate) binds to the antigenantibody complex which leads to the formation of an enzyme labeled antigen-antibody sandwich complex. The enzyme labeled antigen-antibody complex converts the added substrate to form a colored solution. The rate of color formation from the chromogen is a function of the amount of Conjugate complexed with the bound antibody and thus is proportional to the initial concentration of the respective antibodies in the patient sample.
Here's a breakdown of the acceptance criteria and study information for the Varelisa® Cardiolipin IgG Antibodies device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The provided text does not explicitly state specific numerical acceptance criteria for the device. Instead, it focuses on demonstrating "laboratory equivalence" and "substantial equivalence" to a predicate device. The performance is summarized qualitatively.
| Acceptance Criteria Category | Reported Device Performance | Comments |
|---|---|---|
| Laboratory Equivalence | The new device performs as expected from medical literature. Comparisons showed that results obtained within a comparison study analyzing positive, equivocal, and negative sera, as well as results for externally defined Calibrators and Quality Assessment sera, and samples from apparently healthy subjects, supported comparability. Minor differing results noted were probably due to a changed blocking procedure, but the overall conclusion was substantial equivalence. | The criteria are implicitly met by demonstrating that the new device's performance aligns with the predicate and scientific understanding. Specific quantitative targets for agreement (e.g., % positive agreement, % negative agreement) are not provided. |
| Intended Use | The device is designed for semiquantitative and qualitative determination of IgG antibodies against cardiolipin in serum or plasma to aid in the diagnosis of antiphospholipid syndrome (APS) and to evaluate the thrombotic risk in patients with systemic lupus erythematosus (SLE). | The intended use statement itself serves as a high-level criterion, and the study aims to show the device fulfills this use. |
| Substantial Equivalence | All available data support that the new/modified device is substantially equivalent to the predicate/original device, and performs according to state-of-the-art expectations. | This is the overarching "acceptance criterion" for 510(k) clearance in this context. |
2. Sample Sizes and Data Provenance for the Test Set
- Sample Size: The document mentions "positive, equivocal and negative sera," "externally defined Calibrators and Quality Assessment sera," and "samples from apparently healthy subjects (normal population)." However, the specific number of samples in each category tested for the comparison study is not provided.
- Data Provenance: Not explicitly stated. Given the manufacturer (Pharmacia Deutschland GmbH) is in Germany, it is reasonable to infer that some data might be from Europe, but this is not confirmed. The document does not specify whether the data was retrospective or prospective.
3. Number of Experts and Qualifications for Ground Truth
- The document does not mention the use of experts to establish ground truth for the test set. The nature of the comparison (comparing to a predicate device and "externally defined Calibrators and Quality Assessment sera") suggests that the "ground truth" for the test set was likely derived from the established values of these calibrators and known statuses of the clinical samples (positive, negative, equivocal) as determined by the predicate device or other reference methods.
4. Adjudication Method
- Not applicable/Not mentioned. There is no indication of an adjudication method used, as expert consensus for ground truth determination is not described.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not done. This document describes the validation of an in vitro diagnostic (IVD) test kit, which typically does not involve human readers interpreting results in the same way an imaging or pathology AI system would. The "reading" is done by the instrument quantifying antibody levels.
6. Standalone (Algorithm Only) Performance Study
- Yes, this is essentially a standalone performance assessment. The device (an EIA kit) operates without a human-in-the-loop interpreting the primary output. Its performance is evaluated based on its ability to detect and quantify antibodies in samples.
7. Type of Ground Truth Used
-
The ground truth appears to be based on:
- Comparison to a Predicate Device: The performance of the new device was compared against the Varelisa® Cardiolipin (IgG) Antibodies (the original/predicate device).
- Externally Defined Calibrators and Quality Assessment Sera: These materials would have established, reference values for the analytes.
- Known Clinical Status: Samples were categorized as "positive, equivocal and negative sera," implying that their actual status for cardiolipin antibodies was known through other means (likely the predicate or reference methods).
It does not explicitly state "pathology," "expert consensus," or "outcomes data" as the primary form of ground truth for analytical performance, though the clinical relevance (APS diagnosis, thrombotic risk) implies underlying clinical outcomes would have defined the initial understanding of cardiolipin antibodies.
8. Sample Size for the Training Set
- The document does not discuss a separate "training set" in the context of an AI/algorithm. This is an immunoassay kit, not a machine learning model that typically requires a distinct training phase. The " Comparability of the new and the old version" section describes the studies used to demonstrate equivalency.
9. How Ground Truth for the Training Set Was Established
- Not applicable. As this is an immunoassay kit, rather than an AI algorithm requiring a training set, the concept of establishing ground truth for a training set does not apply in the conventional sense. The "training" for such a device is in its biochemical design and optimization during development, validated against known standards and clinical samples.
§ 866.5660 Multiple autoantibodies immunological test system.
(a)
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).(b)
Classification. Class II (performance standards).