(35 days)
The Varelisa® RNP Antibodies EIA kit is designed for the semiquantitative and qualitative determination of RNP antibodies in serum or plasma to aid in the diagnosis of Systemic Lupus Erythematosus (SLE) and Mixed Connective Tissue Disease (MCTD).
The Varelisa RNP Antibodies is an enzyme immunoassay for the semiquantitative and qualitative determination of RNP antibodies in serum or plasma. The determination of RNP antibodies is of central importance for the clinical diagnosis rheumatic autoimmune diseases. The presence of RNP antibodies suggests the possibility of Systemic Lupus Erythematosus (SLE) and Mixed Connective Tissue Diseases (MCTD). The Varelisa RNP Antibodies is an indirect noncompetitive enzyme immunoassay. The wells of a microplate are coated with human recombinant RNP (68 kDa, A, C) antigens. Antibodies specific for RNP present in a patient sample bind to this antigen. In a second step an enzyme labeled second antibody (Conjugate) binds to the antigenantibody complex which leads to the formation of an enzyme labeled antigen-antibody sandwich complex. The enzyme labeled antigen-antibody complex converts the added substrate to form a colored solution. The rate of color formation from the chromogen is a function of the amount of Conjugate complexed with the bound antibody and thus is proportional to the initial concentration of the respective antibodies in the patient sample.
Here's an analysis of the provided text regarding the Varelisa® RNP Antibodies device, structured to address your specific questions.
1. Table of Acceptance Criteria and Reported Device Performance
The provided text describes a "Laboratory Equivalence" study rather than a traditional acceptance criteria study with predefined thresholds. The goal was to demonstrate substantial equivalence to a predicate device.
| Acceptance Criteria (Implied/Study Design) | Reported Device Performance |
|---|---|
| High overall agreement with predicate device (Synelisa™ U1-snRNP Antibodies). | 92% overall agreement with predicate, excluding 8 samples where a different result was expected. |
| Blood donor samples to be negative in both assays. | All blood donor samples (N/A, but implied within the 70 samples) were found negative in both assays. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: 70 samples (including 20 apparently healthy blood donors).
- Data Provenance: Not explicitly stated, but it's a "Laboratory Equivalence" study comparing two in-vitro diagnostic assays. The context implies the samples were human serum or plasma. It is not specified if the samples were retrospective or prospective, or the country of origin.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. The "ground truth" for this comparative study was the result obtained from the predicate device (Synelisa™ U1-snRNP Antibodies), not an independent expert assessment. The study aimed to demonstrate agreement between the new device and an existing, legally marketed device.
4. Adjudication Method for the Test Set
Not applicable. There was no explicit adjudication method described. The comparison was directly between the results of the new device and the predicate device. For some omitted samples, the discrepancies were explained by the compositional differences of the assays (e.g., presence of RNP A and C in the new device, but not in the predicate).
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
Not applicable. This is an in-vitro diagnostic device (an immunoassay) and the submission refers to the device itself, not AI assistance for human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, this study represents a standalone performance evaluation of the Varelisa® RNP Antibodies immunoassay. Its performance was compared directly to the predicate device without human interpretation or intervention as part of the primary measurement.
7. The Type of Ground Truth Used
The "ground truth" for the purpose of the substantial equivalence study was the results obtained from the predicate device (Synelisa™ U1-snRNP Antibodies). This is a common approach for demonstrating equivalence for IVD devices aiming for a 510(k) clearance. Clinical diagnosis (SLE and MCTD) is the ultimate clinical outcome, but for this specific regulatory submission, the predicate device's results served as the reference.
8. The Sample Size for the Training Set
Not applicable. This is an immunoassay kit, not a machine learning model, so there is no "training set" in the context of algorithm development.
9. How the Ground Truth for the Training Set Was Established
Not applicable. There is no training set for this type of device.
§ 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).