(123 days)
- For in vitro diagnostic use only.
- For the qualitative and semi-quantitative detection of IgG antibodies to Sm in human serum by enzyme immunoassay.
- For use as an aid in the diagnosis of systemic lupus erythematosus (SLE).
- For manual use, or for use with the HyPrep System Plus semi-automated fluid handler.
The SeraQuest Anti-Sm test is a solid-phase enzyme immunoassay (EIA), which is performed in microwells, at room temperature, in three thirty minute incubations. It has been developed to detect IgG antibodies which are directed against Sm nuclear antigen (Anti-Sm) , in human serum. The Calibrators in the SeraQuest Anti-Sm test set have been assigned Index values based on an in-house standard. Test results are reported as Index values.
This document describes the 510(k) summary for the SeraQuest® Anti-Sm immunological test system.
1. Table of Acceptance Criteria and Reported Device Performance
The device's performance is demonstrated through a comparative study against a predicate device. While explicit "acceptance criteria" are not listed as predefined thresholds for sensitivity, specificity, and agreement, the study results are presented to support substantial equivalence.
| Metric | Acceptance Criteria (Implied) | Reported Device Performance (SeraQuest Anti-Sm vs. Shield Diastat Anti-Sm) |
|---|---|---|
| Relative Sensitivity | High agreement with predicate positive results | 90.9% (95% CI: 73.9 to 100) |
| Relative Specificity | High agreement with predicate negative results | 93.2% (95% CI: 89.9 to 96.5) |
| Overall Agreement | High overall concordance | 93.1% (95% CI: 89.9 to 96.4) |
2. Sample Size and Data Provenance
- Test Set Sample Size: 236 serum specimens.
- Data Provenance: The study was performed at Quest International, Inc., Miami, FL. The document does not explicitly state the country of origin of the serum specimens, but given the company location, it is likely the data is from the USA. It is a retrospective study as existing serum specimens were tested.
3. Number of Experts and Qualifications for Ground Truth
The document does not mention the use of experts to establish a ground truth for the test set. Instead, the performance is evaluated by comparison to a predicate device, the Shield Diastat Anti-Sm test. The "ground truth" for the performance metrics is based on the results obtained from the predicate device.
The table does include a row indicating "Number of patients with clinically diagnosed SLE." for positive cases, which suggests some clinical diagnosis context, but this is not explicitly stated as the primary ground truth for the comparative study's performance metrics. For the 236 specimens, 10 were positive for clinically diagnosed SLE.
4. Adjudication Method for the Test Set
No adjudication method is described. The comparison is direct between the SeraQuest Anti-Sm test and the Shield Diastat Anti-Sm test.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was mentioned. This device is an in vitro diagnostic (IVD) assay, not an imaging or diagnostic device that requires human interpretation.
6. Standalone Performance Study
Yes, a standalone performance study was done in the sense that the SeraQuest Anti-Sm test was run independently on 236 serum specimens, and its results were then compared to those obtained from the predicate device. The performance metrics (relative sensitivity, specificity, and agreement) are a direct result of this independent testing and subsequent comparison.
7. Type of Ground Truth Used
The primary "ground truth" or reference for the performance metrics (sensitivity, specificity, and agreement) in this study is the predicate device's results (Shield Diastat Anti-Sm test). The comparative study aims to show that the new device performs substantially equivalently to the predicate.
Additionally, for the positive cases, it's mentioned that 10 were "patients with clinically diagnosed SLE," indicating that clinical diagnosis (a form of outcomes data or expert clinical assessment) serves as an underlying reference for the predicate device's intended use and, by extension, the new device's claim for aiding in SLE diagnosis. However, the performance metrics of sensitivity, specificity, and agreement are calculated against the predicate device's results.
8. Sample Size for the Training Set
The document does not provide any information about a "training set" or sample size used for training. This likely indicates that the device's development did not involve a machine learning model, but rather a traditional laboratory assay development process.
9. How the Ground Truth for the Training Set was Established
Since no training set is mentioned for the device itself (as it's an immunoassay, not an AI/ML device), this information is not applicable.
§ 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).