(161 days)
The REAADS IgA anti-B2GPI Test Kit is an in vitro diagnostic assay for the detection and semi-quantitation of I he real and in the man serum as an aid for assessing the risk of thrombosis in individuals with systemic lupus erythematosus (SLE) and lupus-like disorders (antiphospholipid syndrome).
The REAADS IgA anti-B2GPI Test Kit is an enzyme-linked immunosorbent assay (ELISA), utilizing the 96-microwell plate format, similar to the predicate device. Diluted serum samples, calibrator sera, and controls are incubated in microwells coated with purified human Beta-2 Glycoprotein I. Incubation allows the anti-B2GPI antibodies present in the samples to react with the immobilized antigen. After the removal of unbound serum proteins by washing, antibodies specific for human IgA, labeled with horseradish peroxidase (HRP), are added forming complexes with the B2GPI bound antibodies. Following another washing step, the bound enzyme-antibody conjugate is assayed by the addition of a single solution containing tetramethlybenzidine (TMB) and hydrogen peroxide (H2Q2) as the chromogenic substrate. The intensity of the color generated is proportional to the serum concentration of anti-B2GPI antibodies. Optical density is read spectrophotometrically at 450nm. The total incubation time (at room temperature) of the assay is 40 minutes. The assay makes use of a single point calibrator to measure the amount of IgA anti-B2GPI antibodies in patient samples.
Here's an analysis of the acceptance criteria and study detailed in the provided document:
The document describes the REAADS IgA anti-B2GPI Test Kit and its comparison to a predicate device, the QUANTA Lite IgA anti B2GPI ELISA. The core of the acceptance criteria and study revolves around demonstrating substantial equivalence to this legally marketed predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Implicit from Predicate Comparison) | Reported Device Performance (REAADS IgA anti-B2GPI Test Kit) |
|---|---|
| Sensitivity (for unselected SLE patients, compared to predicate) | 25% |
| Sensitivity (for primary APS patient samples, compared to predicate) | 78% |
| Correlation (between device and predicate for individual values in unselected SLE patients) | Coefficient of correlation: 0.721 |
| Statistical Similarity (between device and predicate) | P-value of 0.015 (by single factor ANOVA), indicating statistically similar results |
| General Performance Characteristics (compared to predicate) | Comparable |
| Compliance with published literature (for antiphospholipid syndrome detection) | In compliance |
Note: The document focuses on demonstrating substantial equivalence to an existing predicate device rather than defining new, specific, standalone acceptance thresholds. The "acceptance criteria" are derived from the expectation that the new device's performance will be comparable to, and not significantly worse than, the predicate device across various relevant clinical metrics.
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size:
- "unselected SLE patients": Referenced for sensitivity (25%) and correlation (0.721). The exact number is not specified.
- "primary APS patient samples": Referenced for sensitivity (78%). The exact number is not specified.
- Data Provenance: The studies were described as "In-house studies," meaning they were conducted by CORGENIX, INC. The country of origin and whether the studies were retrospective or prospective are not explicitly stated. Given the context of seeking 510(k) clearance, these are typically retrospective studies on collected patient samples.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts
This information is not provided in the summary. For an in vitro diagnostic test like an ELISA kit, "ground truth" for patient samples (e.g., whether a patient truly has SLE or APS) would typically be established based on accepted clinical diagnostic criteria, possibly involving expert physician diagnosis or other established laboratory tests. The document does not detail how this ground truth was established for the "unselected SLE patients" or "primary APS patient samples."
4. Adjudication Method for the Test Set
The document does not mention any adjudication method used for the test set. Given that this is an ELISA assay, the results are quantitative and objective (optical density readings), so expert adjudication of test results themselves would not typically be applicable. Adjudication might be relevant for establishing the clinical "ground truth" of patient samples, but that detail is missing.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is primarily relevant for imaging diagnostics where human readers interpret images. The REAADS IgA anti-B2GPI Test Kit is an in vitro diagnostic (IVD) ELISA assay, which produces quantitative results read by a spectrophotometer, not human interpretation. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable here.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Yes, the primary study presented is a standalone performance assessment of the REAADS IgA anti-B2GPI Test Kit. The device (an ELISA kit) generates results independently. The comparison is between the REAADS kit and another standalone test (the predicate QUANTA Lite IgA anti B2GPI ELISA). There is no "human-in-the-loop" component in the direct performance of the test itself.
7. The Type of Ground Truth Used
The ground truth for sensitivity calculations appears to be based on patient classification into specific clinical conditions: "unselected SLE patients" and "primary APS patient samples." This implies that patients were diagnosed with these conditions using established clinical criteria, which would involve a combination of clinical symptoms, other laboratory tests, and potentially expert physician diagnosis. It is not explicitly stated whether pathology, outcomes data, or a specific expert consensus was used to define these patient cohorts.
8. The Sample Size for the Training Set
The document does not mention any training set size. As an IVD kit, the device itself is a pre-calibrated assay. While there would have been development and optimization, the data presented pertains to the validation of the finalized kit's performance against a predicate, not a machine learning model requiring a distinct training and test set.
9. How the Ground Truth for the Training Set was Established
Since no training set is discussed or implied for the performance study, this question 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).