(185 days)
The Bio-Plex 2200 ANA Screen is intended for the qualitative screening of specific antinuclear antibodies (ANA), the quantitative detection of antibody to dsDNA, and the semi-quantitative detection of ten (10) separate antibody assays (Chromatin, Ribosomal Protein, SS-A, SS-B, Sm, SmRNP, RNP, Scl-70, Jo-1, and Centromere B.) in human serum and/or EDTA or heparinized plasma. The test system is used as an aid in the diagnosis of systemic rheumatic diseases. The ANA Screen is intended for use with the Bio-Rad BioPlex 2200 System.
The test system is used to screen serum or plasma (EDTA, heparin) samples and detect the presence of antinuclear antibodies as an aid in the diagnosis of systemic rheumatic diseases (Systemic Lupus Erythematosus [SLE], Mixed Connective Tissue Disease [MCTD], Undifferentiated Connective Tissue Disease [UCTD], Sjögren's Syndrome [SS], Scleroderma [Systemic Sclerosis], Dermatomyositis, Polymyositis, Rheumatoid Arthritis [RA], CREST Syndrome, and Raynaud's Phenomenon) in conjunction with clinical findings and other laboratory tests.
The ANA Screen detects the presence of clinically relevant circulating autoantibodies in serum or plasma. These autoantibodies may be useful as an aid in the diagnosis of systemic rheumatic diseases such as Systemic Lupus Erythematosus (SLE), Mixed Connective Tissue Disease (MCTD), Undifferentiated Connective Tissue Disease (UCTD), Sjogren's Syndrome (SS), Scleroderma (Systemic Sclerosis), Dermatomyositis, Polymyositis, Rheumatoid Arthritis (RA), CREST Syndrome, and Raynaud's Phenomenon. Bio-Rad's ANA Screen uses a comprehensive group of autoantigens. Beads are individually couted with individual antigens, so that the presence of each antinuclear and autoimmune antibody can be individually determined. Fluorescence detection facilitates the differentiation of normal and abnormal antibody concentrations.
The ANA Screen uses multiplex flow immunoassay, a methodology that resembles traditional EIA, but permits simultaneous detection and identification of many antibodies in a single tube. Thirteen (13) different populations of dyed beads are coated with antigens associated with systemic autoimmune disease (dsDNA, Chromatin, Ribosomal Protein, SS-A 60, SS-A 52, SS-B, Sm, SmRNP, RNP A, RNP 68, Scl-70, Jo-1 and Centromere B)*. The BioPlex 2200 System combines an aliquot of patient sample, sample diluent, and bead reagent into a reaction vessel. The mixture is incubated at 37°C. After a wash cycle, murine monoclonal anti-human IgG antibody, conjugated to phycoerythrin (PE), is added to the dyed beads and this mixture is incubated at 37°C. The excess conjugate is removed in another wash cycle, and the beads are re-suspended in wash buffer.
The bead mixture is suspended in sheath fluid and then passes through the detector and the identity of the dyed beads is determined by the fluorescence of the dyes. Individually dyed with combinations of two different fluorescent dyes (red and orange), a bead may have one of many possible levels of classifier dye fluorescent intensities. Based on it's fluorescent signature, each bead is classified to it's own unique region. Bio-Rad has used the various combinations of dyes to create 25 uniquely color-coded regions that are associated with 25 unique sets of beads (more can be added if needed). The detector measures at least 200 beads for each analyte, per specimen. The BioPlex 2200 ANA Screen utilizes one of these regions for each of the 13 analytes it detects. Three additional regions are assigned to beads used for quality control purposes.
The BioPlex 2200 ANA Screen is an in-vitro diagnostic device for the qualitative screening of specific antinuclear antibodies (ANA), quantitative detection of anti-dsDNA antibodies, and semi-quantitative detection of ten other specific autoantibodies (Chromatin, Ribosomal Protein, SS-A, SS-B, Sm, SmRNP, RNP, Scl-70, Jo-1, and Centromere B) in human serum and/or EDTA or heparinized plasma. It aids in diagnosing systemic rheumatic diseases.
Here's an analysis of its acceptance criteria and supporting studies as described in the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state pre-defined acceptance criteria (e.g., minimum percentage agreement for clinical performance or maximum CV for reproducibility). However, it reports observed performance metrics from various studies. For the purpose of this analysis, we will infer the desired performance from the presented results, particularly focusing on reproducibility (CV%) and agreement with predicate devices.
| Metric / Antibody Group | Acceptance Criteria (Inferred) | Reported Device Performance (Worst Case for Positive Samples) |
|---|---|---|
| Reproducibility (Intra-assay %CV) | (Not explicitly stated, but generally 90% (Commonly desired for equivalence) | ANA Screen: 79.3% |
| Individual Antibodies: | ||
| dsDNA: 94% | ||
| Chromatin: 86% | ||
| Ribosomal-P: 98% | ||
| SS-A: 97% | ||
| SS-B: 97% | ||
| Sm: 97% | ||
| SmRNP: 96% | ||
| RNP: 95% | ||
| Scl-70: 98% | ||
| Jo-1: 99% | ||
| Centromere: 99% | ||
| Combined Prospective & Retrospective (Overall Agreement vs. predicate EIA) | >90% (Commonly desired for equivalence) | Individual Antibodies: |
| dsDNA: 94% | ||
| Chromatin: 86% | ||
| Ribosomal-P: 97% | ||
| SS-A: 97% | ||
| SS-B: 97% | ||
| Sm: 96% | ||
| SmRNP: 96% | ||
| RNP: 95% | ||
| Scl-70: 97% | ||
| Jo-1: 99.5% | ||
| Centromere: 99% |
2. Sample Size Used for the Test Set and Data Provenance
- Reproducibility Studies: For each of the 11 panel members (10 positive, 1 negative) and the Autoimmune Control Set, 40 replicates were tested per site (2 duplicates x 2 runs x 10 days). Across 3 sites, this totals 120 replicates per panel member. The provenance is internal to Bio-Rad Laboratories (panel preparation) and 3 US testing facilities.
- Prospective Clinical Testing: 908 prospective serum samples. The samples were collected from patients seen at a rheumatology clinic and suspected of having systemic autoimmune disease at 3 U.S. clinical testing sites.
- Retrospective Clinical Testing: 440 retrospective serum samples (known positive for ANA and autoantibodies) and an additional 100 negative serum samples.
- CDC Panel: A masked reference serum panel provided by the Centers for Disease Control (CDC).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number or qualifications of experts used to establish the ground truth for the test sets. Instead, the ground truth for the clinical studies (prospective and retrospective) was established by comparison to commercially available predicate microplate EIA methods. For the CDC panel, the "Expected Results" are based on the CDC's characterization of the reference sera.
4. Adjudication Method for the Test Set
Not applicable. The ground truth was established by predicate EIA methods or CDC characterization, not by expert adjudication of device results.
5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study
Not applicable. This device is an automated immunoassay system, and its performance is assessed against predicate assay methods, not human reader performance.
6. Standalone Performance
Yes, the device's standalone performance was evaluated extensively:
- Reproducibility studies directly measure the precision of the BioPlex 2200 ANA Screen without human interpretation affecting the result.
- Clinical testing (Prospective and Retrospective) compares the BioPlex 2200 ANA Screen's results directly against commercially available predicate EIA methods, which represents its standalone diagnostic capability.
- CDC Panel testing also evaluates the standalone performance of the device against a characterized reference panel.
7. Type of Ground Truth Used
- Reproducibility Studies: Internal characterization of panel members (known antibody status, often spiked concentrations to be near cutoff or high positive).
- Prospective Clinical Testing: Results from commercially available predicate microplate EIA methods.
- Retrospective Clinical Testing: Results from commercially available predicate microplate EIA methods. The samples themselves were selected based on being "known to be positive for ANA and one or more of the autoantibodies" or "known to be negative for ANA," implying prior characterization also likely by established methods.
- CDC Panel: "Expected Results" provided by the Centers for Disease Control (CDC) reference serum panel, which means these samples were characterized by the CDC through their own established methods.
8. Sample Size for the Training Set
The document does not explicitly mention a "training set" in the context of an algorithm or AI. This is a traditional IVD device (immunoassay) where the "training" happens during the development and calibration of the assay reagents and analytical measuring system. The data presented are for performance evaluation, not for training a machine learning model.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no explicitly defined "training set" or AI algorithm learning process detailed for this traditional IVD device. The calibration and optimization of the assay would rely on characterized samples and reference materials, but these are part of the assay development process rather than a machine learning training paradigm.
§ 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).