(45 days)
The Varelisa ssDNA Antibodies EIA kit is designed for the semiquantitative and qualitative determination of anti-single stranded DNA (ssDNA) autoantibodies in serum or plasma. In conjunction with the Varelisa dsDNA Antibodies kit it assists in the diagnosis of systemic lupus erythematosus (SLE) and certain other rheumatic diseases. The test is not definitive in isolation but has to be seen as one parameter in a multicriterion diagnostic process.
Varelisa ssDNA Antibodies is an indirect noncompetitive enzyme immunoassay for the semiquantitative and qualitative determination of ssDNA antibodies in human serum or plasma. Antibodies specific for ssDNA present in the patient sample bind to the antigen. The assay should be used in combination with the Varelisa dsDNA Antibodies.
The test kit contains microplate strips coated with synthetic ssDNA, calibrators, positive and negative controls, enzyme-labeled conjugate, substrate and substrate stop solution, Sample Diluent and wash buffer.
This document describes the Varelisa® ssDNA Antibodies, an indirect noncompetitive enzyme immunoassay for the semi-quantitative and qualitative determination of anti-single stranded DNA (ssDNA) autoantibodies in human serum or plasma. It is intended to assist in the diagnosis of systemic lupus erythematosus (SLE) and other rheumatic diseases, to be used in conjunction with a dsDNA antibodies kit.
1. Table of Acceptance Criteria and Reported Device Performance
The submission document states that "all available data support that the new device, PHARMACIA Varelisa ssDNA Antibodies Assay is substantially equivalent to the predicate device, INOVA QUANTA Lite™ ssDNA Assay, and that the new device performs according to state-of-the-art expectations." However, specific numerical acceptance criteria for performance metrics (such as sensitivity, specificity, accuracy) and their corresponding reported device performance values are not explicitly provided in the given text.
The data provided primarily focuses on demonstrating "comparability" and "substantial equivalence" to the predicate device rather than defining and meeting specific quantitative acceptance criteria. The text mentions "results obtained within a comparison study analyzing positive, equivocal and negative sera" and "results obtained for samples from apparently healthy subjects (normal population)" to support comparability.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Not explicitly defined in numerical terms (e.g., sensitivity > X%, specificity > Y%) | Device performs "as expected from the medical literature" and is "suitable for serum and plasma samples." Confirmed to be "substantially equivalent" to the predicate device based on comparison studies across positive, equivocal, and negative sera, and healthy subjects. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the specific sample size used for the test set during the comparison study. It mentions a "data set including: results obtained within a comparison study analyzing positive, equivocal and negative sera" and "results obtained for samples from apparently healthy subjects (normal population)."
- Sample Size for Test Set: Not explicitly stated.
- Data Provenance: Not explicitly stated (e.g., country of origin). The study is described as a "comparison study" and involves "samples from apparently healthy subjects (normal population)," implying, but not confirming, a prospective collection for this specific study, or at least a retrospective analysis of collected samples for performance evaluation. It is not definitively stated if the data is retrospective or prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not provide information on the number of experts used or their qualifications to establish the ground truth for the test set.
4. Adjudication Method for the Test Set
The document does not specify any adjudication method (e.g., 2+1, 3+1, none) used for the test set.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size with AI vs Without AI Assistance
This device is an in-vitro diagnostic (IVD) immunoassay kit, not an AI-powered diagnostic system involving human readers interpreting images or data with or without AI assistance. Therefore, a multi-reader multi-case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance is not applicable and was not performed.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
This refers to a standalone performance evaluation of the device itself (the immunoassay kit) in determining ssDNA antibodies. The document implies that the "comparison study analyzing positive, equivocal and negative sera" and "results obtained for samples from apparently healthy subjects" were indeed a standalone evaluation of the device against established classifications of these samples. The general principle of an immunoassay kit is to provide a result directly, so the performance described aligns with a "standalone" evaluation of the assay.
7. The Type of Ground Truth Used
The document states that the comparison study involved "positive, equivocal and negative sera" and "samples from apparently healthy subjects (normal population)." This indicates that the ground truth was based on:
- Clinical Diagnosis/Classification: Samples were likely categorized as positive, equivocal, or negative for ssDNA antibodies, or as coming from "apparently healthy subjects," based on established clinical criteria, potentially including other diagnostic tests, clinical symptoms, and expert consensus.
- External Calibrators: "Results obtained for externally defined Calibrators" were also used, suggesting the use of reference materials with known concentrations.
8. The Sample Size for the Training Set
The document does not explicitly mention a training set in the context of an AI/machine learning model. This device is an immunoassay kit for antibody detection, not a machine learning algorithm that requires a distinct training set. The "data set" mentioned seems to be for performance evaluation/comparison rather than training.
9. How the Ground Truth for the Training Set Was Established
As a training set for an AI/machine learning model is not applicable in this context, the method for establishing its ground truth is not mentioned.
§ 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).