(75 days)
This test system is for in vitro diagnostic use for the detection of antineutrophil cytoplasmic antibody in human serum. This test system is to be used as an aid in the detection of antibodies associated with autoimmune vasculitis, Wegener's granulomatosis, microscopic polyarteritis, and idiopathic crescentic glomerulonephritis.
This is an indirect fluorescent antibody test for the semi-quantitative detection of antineutrophil cytoplasmic antibody in human serum
This document describes the Immuno Concepts Antineutrophil Cytoplasmic Antibody (ANCA) Test System with Ethanol Fixed Human Neutrophils. The study aims to demonstrate substantial equivalence to a legally marketed predicate device, the NOVA Lite™ ANCA test system (K961340).
Here's an analysis of the provided information:
1. Acceptance Criteria and Reported Device Performance
The acceptance criteria are implied by the comparison to a predicate device and the desired performance metrics for an ANCA test system. While explicit pass/fail criteria are not stated as numerical cut-offs, the goal is to show the new device performs comparably or better than the predicate, especially when a more definitive "reference method" (ELISA for MPO/PR3 antibodies) is considered.
| Metric (vs. Predicate Device, without reference method) | Acceptance Criteria (Implied: Comparable to Predicate) | Immuno Concepts ANCA Performance |
|---|---|---|
| Relative Sensitivity | N/A | 72.3% |
| Relative Specificity | N/A | 77.1% |
| Overall Agreement | N/A | 74.6% |
| Metric (vs. Reference Method) | Acceptance Criteria (Implied: High Sensitivity & Specificity) | Immuno Concepts ANCA Performance | NOVA Lite™ ANCA Performance (Predicate) |
|---|---|---|---|
| Relative Sensitivity | N/A | 98.4% | 85.8% |
| Relative Specificity | N/A | 93.1% | 74.9% |
| Overall Agreement | N/A | 95.5% | 79.8% |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set 1 (Normal Blood Donors): 497 serum samples. Retrospective. Provenance not explicitly stated, but implies general population.
- Test Set 2 (Previously Determined ANCA Positive): 383 serum samples. Retrospective. Provenance: Reference laboratories in the USA, the United Kingdom, and Australia.
- Test Set 3 (Patients with Known Vasculitides): 102 samples. Retrospective. Provenance: Not explicitly stated, but implies clinical settings where vasculitis diagnoses are made.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not explicitly state the number of experts or their qualifications for establishing the initial ANCA positivity for the "Previously Determined ANCA Positive" samples. However, it mentions samples were obtained from "reference laboratories," implying that these labs, with their inherent expertise, had already categorized the ANCA status using "in-house IFA assays."
For the "Patients with Known Vasculitides" set, the ground truth was "clinically characterized vasculitides," which would involve diagnosis by medical specialists (e.g., rheumatologists, nephrologists) based on clinical presentation, laboratory findings, and potentially biopsy results. The number and specific qualifications of these clinicians are not provided.
4. Adjudication Method for the Test Set
- Discrepant Samples in Normal Blood Donor Set: For initial discrepancies between the subject device and predicate device, a "referee method" was used: ELISA for MPO and PR3 antibodies and Immuno Concepts HEp-2 ANA Test System for ANA.
- Discrepant Samples in Previously Determined ANCA Positive Set: For discrepancies between the subject device and predicate device, the "referee method" was ELISA for MPO and PR3 antibodies.
This indicates a form of adjudication where a third, more specific test (ELISA/ANA) was used to resolve disagreements or clarify the true status of samples, thereby refining the "ground truth" for those specific samples.
5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study
No multi-reader multi-case (MRMC) comparative effectiveness study was mentioned. The study compares the performance of the device and a predicate device (and a reference method) on a set of samples. It does not evaluate the improvement of human readers with AI assistance.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, this was a standalone study. The device, an indirect fluorescent antibody test system, is evaluated for its ability to detect ANCA antibodies. It's an assay performed in a laboratory, and the results are interpreted directly from the test system's output (fluorescence patterns and intensity). There is no "human-in-the-loop" AI component described; the device is the diagnostic tool being assessed.
7. Type of Ground Truth Used
Multiple types of "ground truth" were used and evolved:
- Initial Classification:
- Normal Blood Donors: Implied negative status based on donor population.
- Previously Determined ANCA Positive: "In-house IFA assays" from reference laboratories.
- Patients with Known Vasculitides: "Clinically characterized vasculitides" (clinical diagnosis).
- Refined Ground Truth / Reference Method: For discrepant samples, ELISA for Myeloperoxidase (MPO) and Proteinase 3 (PR3) antibodies, and Immuno Concepts HEp-2 ANA Test System for Antinuclear Antibodies (ANA) were used as a more definitive "reference method" to establish the true ANCA status. The final performance metrics are presented against this refined reference method.
8. Sample Size for the Training Set
The document does not provide any information about a "training set." This type of 510(k) submission, typical for in vitro diagnostic (IVD) devices that are not based on machine learning or AI algorithms, focuses on analytical and clinical performance studies for device validation rather than algorithm training.
9. How the Ground Truth for the Training Set Was Established
Since no training set is discussed, the method for establishing its ground truth is not applicable.
§ 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).