(45 days)
This is an indirect fluorescent antibody test for screening and semiquantitative detection of IgG anti-nDNA antibody in human serum. This test system is to be used as an aid in the diagnosis of systemic lupus erythematosus.
This is an indirect fluorescent antibody test for screening and semiquantitative detection of IgG anti-nDNA antibody in human serum.
Immuno Concepts IgG Anti-nDNA Fluorescent Test System - Acceptance Criteria and Study Details
1. Acceptance Criteria and Reported Device Performance
The study compares the Immuno Concepts IgG Anti-nDNA Fluorescent Test System to a legally marketed predicate device, "Crithidia lucilliae DS DNA Kit (Diagnostic Use)" (K930987). The acceptance criteria are implicitly derived from the reported statistics based on this comparison.
| Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Relative Sensitivity | High (e.g., >90%) | 93.3% |
| Relative Specificity | High (e.g., >90%) | 100% |
| Positive Predictive Value | High (e.g., >90%) | 100% |
| Negative Predictive Value | High (e.g., >90%) | 99.0% |
| Overall Agreement | High (e.g., >90%) | 99.1% |
| Intra-assay CV | Low | 0.78% |
| Inter-assay CV | Low | 0.82% |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 223 samples
- 121 samples submitted to clinical laboratories for anti-nDNA testing.
- 100 blood donors.
- 2 WHO standards known to contain anti-nDNA antibodies.
- Data Provenance: Not explicitly stated, but based on the context of samples submitted to clinical laboratories and blood donors, it is likely retrospective clinical samples. The country of origin is not specified.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Number of Experts: Not applicable. The ground truth for comparative effectiveness was established by the predicate device's results, not by independent experts.
4. Adjudication Method for the Test Set
- Adjudication Method: Not applicable. The study is a direct comparison to a predicate device, where the predicate device's results serve as the reference. There is no mention of an adjudication process by human readers for the primary comparison.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- MRMC Study: No, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed as described. This study directly compared the performance of the new device to a predicate device, rather than assessing human reader performance with and without AI assistance.
6. Standalone Performance Study
- Standalone Performance: Yes, a standalone performance study was done in the sense that the device's diagnostic performance metrics (sensitivity, specificity, etc.) were calculated based on its output compared to a reference standard (the predicate device). The algorithm's output was directly compared to the predicate's output for all 223 samples.
7. Type of Ground Truth Used
- Type of Ground Truth: The ground truth used for the primary comparative effectiveness study was the results obtained from the legally marketed predicate device ("Crithidia lucilliae DS DNA Kit (Diagnostic Use)"). Additionally, two WHO standards known to contain anti-nDNA antibodies were used as positive controls, and samples submitted to clinical laboratories and blood donors provided a range of reactivity.
8. Sample Size for the Training Set
- Sample Size for Training: Not applicable. This device is an indirect fluorescent antibody test kit, not an AI/machine learning algorithm that requires a "training set" in the conventional sense. The device's performance is inherently based on its physical and chemical components and their interaction, which are generally developed through R&D and quality control, rather than machine learning training.
9. How the Ground Truth for the Training Set Was Established
- Ground Truth for Training Set: Not applicable, as explained in point 8. The "training" for this type of test involves developing and optimizing the reagents and assay procedure, ensuring consistency and reliability through standard laboratory practices and quality control, not by processing a "training set" with established ground truth labels for an algorithm.
§ 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).