(147 days)
The QUANTA Flash Sm is a chemiluminescent immunoassay for the semi-quantitative determination of lgG anti-Sm antibodies in human serum. The presence of antibodies, in conjunction with clinical findings and other laboratory tests, can aid in the diagnosis of Systemic Lupus Erythematosus (SLE).
The QUANTA Flash RNP is a chemiluminescent immunoassay for the semi-quantitative determination of lgG anti-ribonucleoprotein (RNP) antibodies in human serum. The presence of anti-RNP antibodies, in conjunction with clinical findings and other laboratory tests, can aid in the diagnosis of Systemic Lupus Erythematosus (SLE) and Mixed Connective Tissue Disease (MCTD).
QUANTA Flash Sm Calibrators are intended for use with the QUANTA Flash Sm chemiluminescent immunoassay for the determination of IgG anti-Sm antibodies in human serum. Each calibrator establishes a point of reference for the working curve that is used to calculate unit values.
QUANTA Flash RNP Calibrators are intended for use with the QUANTA Flash RNP chemiluminescent immunoassay for the determination of IgG anti-RNP antibodies in human serum. Each calibrator establishes a point of reference for the working curve that is used to calculate unit values.
QUANTA Flash Sm Controls are intended for use with the QUANTA Flash Sm chemiluminescent immunoassay for quality control in the determination of IgG anti-Sm antibodies in human serum.
QUANTA Flash RNP Controls are intended for use with the QUANTA Flash RNP chemiluminescent immunoassay for quality control in the determination of IgG anti-RNP antibodies in human serum.
The QUANTA Flash Sm and RNP assays are designed to run on the BIO-FLASH instrument. This platform is a fully automated closed system with continuous load and random access capabilities that automatically processes the samples, runs the assay and reports the results. It includes liquid handling hardware, luminometer and computer with software-user interface. The QUANTA Flash Sm and RNP assays utilize a reagent cartridge format, which is compatible with the BIO-FLASH instrument.
Native Sm or RNP antigen that is purified from calf thymus is coated onto paramagnetic beads. The bead suspension is lyophilized and stored in the bead tube. Prior to use in the BIO-FLASH system, the sealed reagent tubes are pierced with the reagent cartridge lid and the beads are rehydrated and resuspended using resuspension buffer by pipetting up and down with a transfer pipette. The reagent cartridge is then loaded onto the BIO-FLASH instrument. Samples are also loaded onto the instrument in sample racks. A patient serum sample is prediluted by the BIO-FLASH with system rinse in a small disposable plastic cuvette. Small amounts of the diluted patient serum, the beads, and assay buffer are all combined into a second cuvette, and mixed. This cuvette is then incubated at 37°C. The beads are magnetized and washed several times. Isoluminol conjugated anti-human IgG antibodies are then added to the cuvette, and again incubated at 37°C. The beads are magnetized and washed repeatedly. The isoluminol conjugate is oxidized when Trigger 1 (Fe(III)coproporphyrin in sodium hydroxide solution) and Trigger 2 (urea-hydrogen peroxide in sodium chloride solution) are added to the cuvette, and the flash of light produced from this reaction is measured as Relative Light Units (RLU) by the BIO-FLASH optical system. The RLU are proportional to the amount of isoluminol conjugate that is bound to the human lgG, which is in turn proportional to the amount of anti-RNP antibodies bound to the Sm or RNP on the beads.
For quantitation, the QUANTA Flash Sm and RNP assays utilize a predefined lot specific Master Curve that is uploaded onto the instrument through the reagent cartridge barcode. Every new lot number of reagent cartridge must be calibrated before first use with the QUANTA Flash Sm and RNP Calibrators. Based on the results obtained with the two Calibrators included in the Calibrator Set (sold separately), an instrument specific Working Curve is created, which is used to calculate chemiluminescent units (CU) from the instrument signal (RLU) obtained for each sample.
The QUANTA Flash Sm kit contains the following materials:
One (1) QUANTA Flash Sm Reagent Cartridge
One (1) vial of Resuspension buffer
One (1) Transfer pipette
The QUANTA Flash Sm reagent cartridge contains the following reagents for 50 determinations:
- Sm antigen coated paramagnetic beads, lyophilized.
- Assay buffer colored pink, containing Tris-buffered saline, Tween 20, protein stabilizers and preservatives.
- Tracer IgG Isoluminol labeled anti-human IgG antibodies in buffer, containing protein stabilizers and preservative.
The QUANTA Flash RNP kit contains the following materials:
One (1) QUANTA Flash RNP Reagent Cartridge
- One (1) vial of Resuspension buffer
- One (1) Transfer pipette
The QUANTA Flash RNP reagent cartridge contains the following reagents for 50 determinations:
- RNP antigen coated paramagnetic beads, lyophilized.
- Assay buffer colored pink, containing Tris-buffered saline, Tween 20, protein stabilizers and preservatives.
- Tracer IgG Isoluminol labeled anti-human IgG antibodies in buffer, containing protein stabilizers and preservative.
The QUANTA Flash Sm Calibrators kit and the QUANTA Flash™ RNP Calibrators kit each contain 2 vials of Calibrators:
QUANTA Flash Sm Calibrators:
- QUANTA Flash Sm Calibrator 1: Two (2) barcode labeled tubes containing 0.3 ml prediluted, ready to use reagent. Calibrators contain human antibodies to Sm in buffer, protein stabilizers, and preservatives.
- QUANTA Flash Sm Calibrator 2: Two (2) barcode labeled tubes containing 0.3 mL prediluted, ready to use reagent. Calibrators contain human antibodies to Sm in buffer, protein stabilizers, and preservatives.
QUANTA Flash RNP Calibrators:
- QUANTA Flash RNP Calibrator 1: Two (2) barcode labeled tubes containing 0.3 mL prediluted, ready to use reagent. Calibrators contain human antibodies to RNP in buffer, protein stabilizers, and preservatives.
- QUANTA Flash RNP Calibrator 2: Two (2) barcode labeled tubes containing 0.3 mL prediluted, ready to use reagent. Calibrators contain human antibodies to RNP in buffer, protein stabilizers, and preservatives.
The QUANTA Flash Sm Controls kit and the QUANTA Flash™ RNP Controls kit each contain 2 vials of Negative Control and two vials of Positive Control:
QUANTA Flash Sm Controls:
- QUANTA Flash™ Sm Negative Control: Two (2) barcode labeled tubes containing 0.5 mL, ready to use reagent. Controls contain human antibodies to Sm in buffer, protein stabilizers, and preservatives.
- QUANTA Flash™ Sm Positive Control: Two (2) barcode labeled tubes containing 0.5 ml, ready to use reagent. Controls contain human antibodies to Sm in buffer, protein stabilizers, and preservatives.
QUANTA Flash RNP Controls:
- QUANTA Flash™ RNP Negative Control: Two (2) barcode labeled tubes containing 0.5 mL, ready to use reagent. Controls contain human antibodies to RNP in buffer, protein stabilizers, and preservatives.
- QUANTA Flash™ RNP Positive Control: Two (2) barcode labeled tubes containing 0.5 ml, ready to use reagent. Controls contain human antibodies to RNP in buffer, protein stabilizers, and preservatives.
Acceptance Criteria and Device Performance for QUANTA Flash® Sm and RNP Assays
This information is extracted from the provided 510(k) summary for the QUANTA Flash® Sm and QUANTA Flash® RNP assays.
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Characteristic | Acceptance Criteria | QUANTA Flash® Sm Performance | QUANTA Flash® RNP Performance |
|---|---|---|---|
| Precision | All %CV values within 15% | All %CV values within 15% (e.g., Total Precision: 8.7%-11.5%) | All %CV values within 15% (e.g., Total Precision: 4.8%-10.8%) |
| Reproducibility | All %CV values within 15% | All %CV values within 15% (e.g., Total CV: 7.0%-8.3%) | All %CV values within 15% (e.g., Total CV: 2.8%-2.9%) |
| Limit of Detection (LoD) | Proportions of false positives (alpha) 90% at 2 weeks, no individual data point ≤ 80% recovery; OR Individual data points: recovery values > 90% at day 14 | Fulfilled (1-year expiration dating assigned) | Fulfilled (1-year expiration dating assigned) |
| Shelf Life (Microparticles) | Regression analysis: lower 95% CI ≥ 85% at 2 weeks, no individual data point ≤ 75% recovery | Fulfilled (1-year expiration dating assigned) | Fulfilled (1-year expiration dating assigned) |
| In-use Stability (Calibrators) | 5 successful calibrations over 8.5 hours, RLU recovery 90%-110% compared to first use, patient samples within expected range | Met (4 calibrations over 8 hours supported) | Met (4 calibrations over 8 hours supported) |
| In-use Stability (Controls) | All replicates within established range, linear regression line of %recovery between 85%-115% at run 15 | Met (%CV 5.9% for negative, 4.8% for positive) | Met (%CV 5.9% for negative, 6.9% for positive) |
| In-use Stability (Reagent Cartridge) | Lower 95% CI of regression line reaches 85% recovery, or 2% or more recovery data ≤ 75% | 33 days | 28 days |
| Cut-off Establishment | Established at 99th percentile of reference subjects using non-parametric percentile method (CLSI C28-A3c) | 20 CU | 20 CU |
| Clinical Sensitivity (Sm for SLE) | Not explicitly defined as an acceptance criterion within the context of a specific pre-market requirement but presented as performance data for diagnostic utility. | 14.4% (9.1-21.1%) | N/A |
| Clinical Specificity (Sm for SLE) | Not explicitly defined as an acceptance criterion within the context of a specific pre-market requirement but presented as performance data for diagnostic utility. | 97.9% (95.1-99.3%) | N/A |
| Clinical Sensitivity (RNP for SLE/MCTD) | Not explicitly defined as an acceptance criterion within the context of a specific pre-market requirement but presented as performance data for diagnostic utility. | N/A | 37.1% (30.0%-44.6%) |
| Clinical Specificity (RNP for SLE/MCTD) | Not explicitly defined as an acceptance criterion within the context of a specific pre-market requirement but presented as performance data for diagnostic utility. | N/A | 95.1% (91.6%-97.5%) |
| Method Comparison (Sm vs. Predicate) | Not explicitly defined as a numerical acceptance criterion, but data is presented to show substantial equivalence. | Positive Agreement: 92.1% (78.6 - 98.3%); Negative Agreement: 92.6% (84.6 - 97.2%); Total Agreement: 92.4% (86.1 - 96.5%) | N/A |
| Method Comparison (RNP vs. Predicate) | Not explicitly defined as a numerical acceptance criterion, but data is presented to show substantial equivalence. | N/A | Positive Agreement: 80.7% (68.1 - 90.0%); Negative Agreement: 94.5% (88.5 - 98.0%); Total Agreement: 89.8% (84.2 - 94.0%) |
Note on "Acceptance Criteria" for Clinical Sensitivity/Specificity: For diagnostic device submissions like this, the criteria are often for demonstrating reasonable performance that supports the intended use and shows substantial equivalence to a predicate, rather than predefined absolute thresholds that must be met. The device sponsor presents the performance data to the FDA for review against the predicate and the defined intended use.
2. Sample Sizes Used for the Test Set and Data Provenance
For Clinical Sensitivity and Specificity:
-
QUANTA Flash Sm:
- Test Set Size: 379 samples
- 63 SLE patients (Neuss Center for Rheumatology, Neuss, Germany)
- 83 SLE patients (Dr. Carlos von Mühlen, Germany)
- 74 systemic sclerosis patients
- 70 rheumatoid arthritis patients
- 5 Sjögren's syndrome patients
- 53 patients with other systemic rheumatic diseases
- 2 patients with autoimmune liver disease
- 19 patients with viral hepatitis
- 10 patients with other infectious diseases (5 HIV, 5 syphilis)
- Data Provenance: Mixed (Germany, likely other origins for disease controls). Retrospective, as these were existing samples used for validation.
- Test Set Size: 379 samples
-
QUANTA Flash RNP:
- Test Set Size: 424 samples
- 62 SLE patients (Neuss Center for Rheumatology, Neuss, Germany)
- 32 MCTD patients (Neuss Center for Rheumatology, Neuss, Germany)
- 84 SLE patients (Dr. Carlos von Mühlen, Germany)
- 48 patients with other systemic rheumatic diseases
- 2 patients with autoimmune liver disease
- 6 patients with Sjögren's syndrome
- 76 patients with systemic sclerosis
- 70 patients with rheumatoid arthritis
- 14 patients with polymyositis/dermatomyositis
- 20 patients with viral hepatitis
- 10 patients with other infectious diseases (5 HIV, 5 syphilis)
- Data Provenance: Mixed (Germany, likely other origins for disease controls). Retrospective.
- Test Set Size: 424 samples
For Reference Range Establishment:
-
QUANTA Flash Sm:
- Test Set Size: 232 subjects (129 apparently healthy blood donors, 41 non-autoimmune thyroid disease, 42 autoimmune thyroid disease, 20 infectious diseases)
- Data Provenance: Not explicitly stated, but appears to be general reference populations. Retrospective.
-
QUANTA Flash RNP:
- Test Set Size: 255 subjects (127 apparently healthy blood donors, 41 non-autoimmune thyroid disease, 42 autoimmune thyroid disease, 20 infectious diseases, 25 rheumatoid arthritis)
- Data Provenance: Not explicitly stated, but appears to be general reference populations. Retrospective.
For Method Comparison:
-
QUANTA Flash Sm:
- Test Set Size: 119 samples (from clinical validation studies, proficiency surveys (CAP and NEQAS), and apparently healthy blood donors)
- Data Provenance: Mixed (includes proficiency testing samples, likely retrospective).
-
QUANTA Flash RNP:
- Test Set Size: 167 samples (from clinical validation studies and apparently healthy blood donors)
- Data Provenance: Mixed (likely retrospective).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not explicitly state the number or qualifications of "experts" used to establish the ground truth for the clinical test sets of patients with SLE, MCTD, and other conditions. For these types of diagnostic immunoassays, the "ground truth" for patient classification (e.g., "SLE patient," "MCTD patient") is typically based on a clinical diagnosis by treating physicians, often rheumatologists, according to established diagnostic criteria (e.g., ACR criteria for SLE). The specific details of how these clinical diagnoses were confirmed for each sample are not provided, nor is the number or specific qualifications of the clinicians who made the diagnoses. These are generally assumed to be standard clinical practice in the institutions mentioned (e.g., Neuss Center for Rheumatology).
4. Adjudication Method for the Test Set
No explicit adjudication method (e.g., 2+1, 3+1) is described for the clinical diagnoses that constitute the ground truth. The samples were collected from diagnosed patient populations.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was done. This device is an in-vitro diagnostic (IVD) assay, not an imaging or algorithmic-interpretation device that would involve human readers interpreting results with or without AI assistance. The output is a semi-quantitative antibody level.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, this is implicitly a standalone study. The device is an automated chemiluminescent immunoassay system (BIO-FLASH instrument with QUANTA Flash assays). The results (Chemiluminescent Units, CU) are generated by the algorithm/system and reported directly. While a human laboratory technician operates the instrument and interprets the final CU values against a cutoff, the performance metrics (sensitivity, specificity, precision, etc.) presented are characteristic of the assay system's inherent ability to detect and quantify the antibodies from the sample, without human-in-the-loop "improvement" on the detection itself.
7. Type of Ground Truth Used
The ground truth for the clinical studies (sensitivity and specificity) was clinical diagnosis (e.g., Systemic Lupus Erythematosus, Mixed Connective Tissue Disease) provided by the centers from which the patient samples were sourced. For analytical studies (precision, linearity, LoD, etc.), the ground truth was based on established analytical methods and reference materials.
8. Sample Size for the Training Set
The document does not mention a "training set" in the context of an AI/machine learning algorithm. For these types of immunoassay devices, the equivalent concept might be the samples used for assay development, initial optimization, and master curve establishment.
- Master Curve: A predefined lot-specific Master Curve is uploaded onto the instrument. This curve is central to the assay's function. The data used to establish this master curve is not explicitly detailed in terms of sample size or how the ground truth was established, but it would typically involve a large set of characterized samples with known concentrations to define the relationship between RLU and CU.
- Calibrator and Control Value Assignment: "at least two instruments, on at least two lots of reagent cartridge, in replicates of 10 to determine final value assignment." This is akin to a small-scale internal dataset used to finalize product specifications. There are currently no recognized international standards for the measurement of anti-RNP antibodies, so values are traceable to in-house standards.
9. How the Ground Truth for the Training Set was Established
As noted above, there is no explicit "training set" in the AI/ML sense. The functionality of the device relies on:
- Reagent Development & Formulation: The components (antigens, antibodies, buffers, etc.) are developed and purified based on chemical and biological principles to ensure specific binding.
- Master Curve Generation: While not explicitly detailed, the Master Curve that links RLU to CU for each lot of reagents is established using a set of reference samples with known concentrations of anti-Sm or anti-RNP antibodies. The "ground truth" for these reference samples would be determined through rigorous characterization using established analytical methods, potentially including comparative analysis with existing gold standard methods or highly characterized internal reference materials. The document states "Calibrator and Control values are directly traceable to in-house Standards that are used to create the Master Curve." This implies that internal, well-characterized standards form the basis of the "ground truth" for the quantitative aspect of the assay.
§ 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).