(36 days)
This is an enzyme immunoassay test system for the detection of antinuclear antibodies in human serum. This test system is to be used as an aid in the detection of antibodies associated with systemic rheumatic disease.
This is an enzyme immunoassay for the detection of antinuclear antibodies in human serum.
This document describes the RELISA® ANA Screening Test System, an enzyme immunoassay for the detection of antinuclear antibodies in human serum, intended as an aid in detecting antibodies associated with systemic rheumatic disease.
1. Acceptance Criteria and Reported Device Performance:
The primary acceptance criterion appears to be "overall agreement" with a reference method. The initial comparison to the predicate device set the stage, but a "referee method" (Immuno Concepts HEp-2000® ANA-Ro Test System using indirect fluorescent antibody technique) was ultimately used to clarify "false positive" and "false negative" results.
| Acceptance Criterion | Reported Device Performance (Revised with Referee Method) |
|---|---|
| Overall Agreement | 93.5% |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size:
- Initial Comparison (with Predicate device): 214 (Positive) + 46 (Predicate Negative/Test Positive) + 12 (Predicate Positive/Test Borderline) + 105 (Predicate Negative/Test Borderline) + 8 (Predicate Positive/Test Negative) + 787 (Negative) = 1172 samples.
- Revised Comparison (with Referee Method): The number of samples re-evaluated for the "referee method" was 79 "false positive" (from the initial comparison) and 4 "false negative" samples. The table provided for the revised comparison then summarizes the results for the entire cohort of 1172 samples based on the referee method's classification for the previously discrepant cases.
- Data Provenance: Not explicitly stated, but given context of the submission, it is assumed to be retrospective clinical samples. No country of origin is mentioned.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts:
- Number of Experts: Not explicitly stated.
- Qualifications of Experts: The ground truth for the referee method involved use of the "indirect fluorescent antibody technique" and observation of "clearly discernible ANA patterns." This strongly implies interpretation by trained laboratory professionals, likely medical technologists or clinical immunologists with expertise in ANA testing. Specific qualifications (e.g., years of experience, board certification) are not provided.
4. Adjudication Method for the Test Set:
- Adjudication Method: The document describes a specific process for adjudication of discrepant results: "The large number of 'false positive' samples seen with the Immuno Concepts test was troubling, so we tested all of these sera for antinuclear antibodies using Immuno Concepts HEp-2000® ANA-Ro Test System (K944096 & K972145)." This indicates a targeted re-evaluation of initially discrepant samples using a more definitive "referee method" (indirect fluorescent antibody technique), where the results of this referee method were then considered the "true" classification. This is a form of discrepancy resolution with a gold standard.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
- There is no indication of an MRMC comparative effectiveness study being performed. The study focuses on comparing the new device against a predicate device and a "referee method," not on human reader performance with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
- Yes, a standalone performance study was conducted. The RELISA® ANA Screening Test System is an enzyme immunoassay, and its performance was evaluated directly against other laboratory tests (the predicate device and the indirect fluorescent antibody technique) without explicit human intervention in the interpretation of the RELISA results for the purpose of the study. The results are from the device itself.
7. The Type of Ground Truth Used:
- The initial comparison used the predicate device's results as a reference.
- The refined comparison, which led to the final performance metrics, used the indirect fluorescent antibody technique (IFA) performed with the Immuno Concepts HEp-2000® ANA-Ro Test System as the "referee method" or gold standard for establishing ground truth, especially for discrepant samples. IFA is generally considered a highly sensitive and specific method for ANA detection and pattern recognition, often serving as a reference method in clinical immunology.
8. The Sample Size for the Training Set:
- The document does not explicitly mention a separate training set or its sample size. This type of submission for an in vitro diagnostic (IVD) device typically focuses on clinical validation (test set) for regulatory approval rather than machine learning model training.
9. How the Ground Truth for the Training Set Was Established:
- As no training set is explicitly described, there is no information provided on how its ground truth might have been established.
§ 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).