(73 days)
- For the quantitative detection of IqG antibodies to thyroglobulin in human serum by enzyme immunoassay.
- The SeraQuest Anti-thyroglobulin test can be used with other serological tests and clinical findings, to aid in the diagnosis of thyroid diseases such as Autoimmune Thyroiditis and Graves' disease.
- For in vitro diagnostic use only.
The SeraQuest Anti-Thyroglobulin 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 IqG antibodies which are directed against thyroglobulin, in human serum.
The Calibrators in the SeraQuest Anti-Thyroglobulin test kit have been assigned values based on the NIBSC standard. Test results are reported as international units per milliliter (IU/mL).
This document describes the validation study for the SeraQuest Anti-Thyroglobulin test.
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (Implicit from Predicate Equivalence) | Reported Device Performance (SeraQuest vs. Varelisa) |
|---|---|
| Relative Sensitivity: Expected to be comparable to the predicate device, demonstrating adequate detection of positive cases. | Relative Sensitivity: 97.0% (95% C.I.: 91.4% - 100%) |
| Relative Specificity: Expected to be comparable to the predicate device, demonstrating adequate exclusion of negative cases. | Relative Specificity: 100% (95% C.I.: 99.9% - 100%) |
| Overall Agreement: Expected to be high, indicating substantial concordance between the device and the predicate. | Overall Agreement: 99.2% (95% C.I.: 97.5% - 100%) |
2. Sample Size Used for the Test Set and Data Provenance:
- Test Set Sample Size: 144 serum specimens.
- Data Provenance: The study was conducted at Quest International, Inc., and the specimens were "serum specimens," implying human origin. The document does not explicitly state the country of origin or whether the data was retrospective or prospective. Given the nature of a 510(k) submission for device clearance, it is generally assumed to be a prospective or at least properly collected retrospective dataset for regulatory purposes.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- This study did not use human experts to establish ground truth. Instead, it used a predicate device (Pharmacia Varelisa TG Antibodies test) as the reference standard. The performance of the SeraQuest Anti-Thyroglobulin test was compared directly to this established and legally marketed device.
4. Adjudication Method for the Test Set:
- No adjudication method by human experts was used for the test set. The comparison was directly against the results of the predicate device. When a discordant result occurred between the SeraQuest and Varelisa tests (1 specimen), it was further tested by a second legally marketed device, the Scimedix Anti-Thyroglobulin Test. This serves as a form of secondary verification rather than adjudication by expert consensus.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study is an in-vitro diagnostic device comparison, not an imaging or clinical diagnostic aid that typically involves human readers.
6. Standalone (Algorithm Only) Performance Study:
- Yes, a standalone performance study was done. The SeraQuest Anti-Thyroglobulin test (the algorithm/device) was run independently on the 144 serum specimens, and its results were then compared to the results obtained from the predicate device (Pharmacia Varelisa TG Antibodies test), which also operated in a "standalone" fashion.
7. Type of Ground Truth Used:
- The "ground truth" used in this study was the results obtained from a legally marketed predicate device (Pharmacia Varelisa TG Antibodies test). This is a common approach for demonstrating substantial equivalence for in-vitro diagnostic devices. For the one discordant specimen, a second legally marketed device (Scimedix Anti-Thyroglobulin Test) was used for further verification, which gave an equivocal result.
8. Sample Size for the Training Set:
- The document does not explicitly state the sample size used for a "training set." This type of in-vitro diagnostic device likely undergoes development and internal validation and optimization with various samples, but the FDA submission focuses on the validation against a predicate device using a specific test set. The 144 specimens were for the performance study, not explicitly described as a training set.
9. How the Ground Truth for the Training Set Was Established:
- As a training set is not explicitly described or quantified, the method for establishing its ground truth is not provided. However, for the development and optimization of such an assay, ground truth would typically be established through a combination of well-characterized clinical samples (e.g., from patients with confirmed autoimmune thyroiditis or Graves' disease, and healthy controls), using reference methods or established clinical diagnoses.
§ 866.5870 Thyroid autoantibody immunological test system.
(a)
Identification. A thyroid autoantibody immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the thyroid autoantibodies (antibodies produced against the body's own tissues). Measurement of thyroid autoantibodies may aid in the diagnosis of certain thyroid disorders, such as Hashimoto's disease (chronic lymphocytic thyroiditis), nontoxic goiter (enlargement of thyroid gland), Grave's disease (enlargement of the thyroid gland with protrusion of the eyeballs), and cancer of the thyroid.(b)
Classification. Class II (performance standards).