Search Results

QUANTA Flash Ro60 is a chemiluminescent immunoassay for the semi-quantitative determination of IgG anti-Ro60 autoantibodies in human serum. The presence of anti-Ro60 autoantibodies, in conjunction with clinical findings and other laboratory tests, is an aid in the diagnosis of Systemic Lupus Erythematosus and Sjögren's Syndrome.

QUANTA Flash Ro60 Calibrators are intended for use with the QUANTA Flash Ro60 Reagents for the determination of Ig G anti-Ro60 autoantibodies in human serum. Each calibrator establishes a point of reference for the working curve that is used to calculate unit values.

QUANTA Flash Ro60 Controls are intended for use with the QUANTA Flash Ro60 reagents for quality control in the determination of IgG anti-Ro60 autoantibodies in human serum.

The QUANTA Flash Ro60 assay is 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 Ro60 assay utilizes a reagent cartridge format, which is compatible with the BIO-FLASH instrument.

Purified recombinant Ro60 antigen 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. Serum samples are 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(II)coproporphyrin in sodium hydroxide solution) and Trigger 2 (ureahydrogen 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 IgG, which is in turn proportional to the amount of anti-Ro60 antibodies bound to the corresponding beads.

For quantitation, the QUANTA Flash Ro60 assay utilizes 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 Ro60 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 Ro60 kit contains the following materials:

One (1) QUANTA Flash Ro60 Reagent Cartridge

One (1) vial of Resuspension buffer

One (1) Transfer pipette

The QUANTA Flash Ro60 reagent cartridge contains the following reagents for 50 determinations:

• a. Ro60 antigen coated paramagnetic beads, lyophilized.
• b. Assay buffer - colored pink, containing Tris-buffered saline, Tween 20, protein stabilizers and preservatives.
• C. Tracer IgG - Isoluminol labeled anti-human IgG antibodies in buffer, containing protein stabilizers and preservative.

The QUANTA Flash Ro60 Calibrators kit contains two vials of Calibrator 1 and two vials of Calibrator 2:

QUANTA Flash Ro60 Calibrators:

• QUANTA Flash Ro60 Calibrator 1: Two (2) barcode labeled tubes containing 0.3 mL ı prediluted, ready to use reagent. Calibrators contain human antibodies to Ro60 in stabilizers and preservatives.
• -QUANTA Flash Ro60 Calibrator 2: Two (2) barcode labeled tubes containing 0.3 mL prediluted, ready to use reagent. Calibrators contain human antibodies to Ro60 in stabilizers and preservatives.

The QUANTA Flash Ro60 Controls kit contains two vials of Negative Control and two vials of Positive Control:

QUANTA Flash Ro60 Controls:

• । QUANTA Flash Ro60 Negative Control: Two (2) barcode labeled tubes containing 0.5 mL, ready to use reagent. Controls contain human antibodies to Ro60 in stabilizers and preservatives.
• i QUANTA Flash Ro60 Positive Control: Two (2) barcode labeled tubes containing 0.5 mL, ready to use reagent. Controls contain human antibodies to Ro60 in stabilizers and preservatives.

The document describes the analytical and clinical performance of the QUANTA Flash® Ro60 chemiluminescent immunoassay for the semi-quantitative determination of IgG anti-Ro60 autoantibodies in human serum.

Here's a breakdown of the requested information:

1. Table of Acceptance Criteria and Reported Device Performance:

2. Sample Size Used for the Test Set and Data Provenance:

• Precision Study: 10 samples (run in duplicates, twice a day, for 21 days), 84 replicates each.
• Reproducibility Study: 3 samples (run in quadruplicates, two times a day, for 10 days), 80 data points per sample.
• Limit of Detection (LoD) Study: 120 determinations (60 blank, 60 low-level samples) per reagent lot. 4 low-level samples (diluted anti-Ro60 positive samples) for LoD determination.
• Limit of Blank (LoB) Study: 4 blank samples (System Rinse) from two different lots, run in replicates of five per day for 3 days. 60 data points per lot.
• Linearity Study: 3 serum samples (diluted in 10% increments).
• Interference Study: 3 specimens (one near-cutoff negative, one weak positive, one high positive), spiked with interfering substances at three concentrations.
• Cross-reactivity Study: 213 "control" clinical samples from patients with various autoimmune diseases or infectious disease serology.
• Lot to Lot Comparison Study: 21 unique samples and 2 Positive Controls (23 specimens in total).
• Sample Stability Study: 6 samples (negative, around cut-off, positive).
• Accelerated Stability Studies: 3 lots of beads and 3 lots of Calibrators and Controls.
• Onboard Stability (Calibrators): Not explicitly stated, but involved running Calibrators 5 times over 8.5 hours with Controls and a panel of characterized patient specimens.
• Onboard Stability (Controls): 2 vials of each Control, assayed twice a day for a total of 20 runs.
• Reagent Cartridge Onboard Stability: Three lots of cartridges, tested with up to 6 serum specimens and controls.
• Real-time Stability: Not explicitly stated, but involved testing at various time points (3, 6, 9, 12 months for Calibrators/Controls; 2, 5, 8, 12 months for reagent cartridge).
• Reference Range Establishment: 156 subjects (apparently healthy blood donors, viral hepatitis, HIV, syphilis, rheumatoid arthritis patients). Data provenance not specified beyond "commercial sources" for certain materials.
• Clinical Performance (Sensitivity/Specificity): 475 characterized samples for the Validation Set (from Sjögren's Syndrome, SLE, and various control groups). Data provenance not specified, but likely from a clinical setting.
• Method Comparison: 143 samples from SS and SLE patients and disease controls.

The data provenance for most studies is not explicitly stated beyond general descriptions ("human serum," "commercial sources," "characterized samples"). It is not specified whether the studies were retrospective or prospective, or the country of origin for the patient/sample cohorts.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:

The document does not mention the use of experts to establish ground truth for the test set. For the clinical performance, samples were "characterized" and grouped into patient categories (e.g., Sjögren's Syndrome, SLE), but the method of this characterization (e.g., clinical diagnosis by a panel of rheumatologists, specific diagnostic criteria) and the number/qualifications of experts involved are not provided.

4. Adjudication Method:

The document does not describe any adjudication method (e.g., 2+1, 3+1) for the test set.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

No MRMC comparative effectiveness study is mentioned. This device is an immunoassay, typically read by an instrument rather than human readers, so such a study would not be applicable.

6. Standalone Performance:

Yes, the entire document details the standalone performance of the QUANTA Flash® Ro60 immunoassay. All the analytical and clinical performance characteristics (precision, reproducibility, linearity, interference, stability, sensitivity, specificity, method comparison) are based on the algorithm's (instrument's) output without human intervention in the result interpretation beyond setting the cut-off. The device is described as "a fully automated closed system with continuous load and random access capabilities that automatically processes the samples, runs the assay and reports the results."

7. Type of Ground Truth Used:

• Analytical Studies (Precision, Reproducibility, Linearity, Interference, LoD, LoB, Lot-to-Lot, Sample Stability, Instrument Stability): Ground truth is typically based on pre-defined concentrations, spiked samples, or reference materials. For example, for linearity, expected values were based on dilution factors. For LoD/LoB, the truth was whether a sample was blank or low-level.
• Clinical Performance (Sensitivity, Specificity) and Cross-reactivity: Ground truth was based on clinical diagnoses (e.g., Sjögren's Syndrome, SLE, Graves' Disease, etc.) for the characterized samples. For cross-reactivity, it also included the presence of specific autoantibodies or infectious disease serology.
• Cut-off Establishment: Used a reference population of 156 subjects (apparently healthy, viral hepatitis, HIV, syphilis, rheumatoid arthritis) and also included 12 proficiency testing samples from CAP and UKNEQAS with known consensus/target results.
• Method Comparison: Ground truth was the result from a predicate device (Hycor AUTOSTAT™ II Anti-SS-A Ro ELISA).

8. Sample Size for the Training Set:

The document does not specify a separate "training set" in the context of machine learning. For an immunoassay, the "training" equivalent would be the data used to establish master curves, calibrator values, and cut-offs.

• Master Curve/Calibrator Values: Based on "in-house Standards" and trial dilutions (sample size for these not specified, but implied to be robust enough for value assignment).
• Cut-off Establishment: 156 subjects (reference population) and 12 proficiency testing samples were used to establish the cut-off. This could be considered part of the "training" for the interpretation of results into positive/negative.

9. How Ground Truth for the Training Set Was Established:

As explained in point 8, if we consider cut-off establishment and master curve definition as part of "training":

• Master Curves and Calibrator/Control Values: Established internally using "in-house Standards" and extensive testing on multiple instruments and reagent lots.
• Cut-off for Classification: Established by analyzing the results from a reference population of 156 subjects using statistical methods (99th percentile, non-parametric method) and further informed by 12 proficiency testing samples with known consensus/target results from external quality assessment schemes (CAP, UKNEQAS).

Ask a specific question about this device