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QUANTA Flash Jo-1 is a chemiluminescent immunoassay for the semi-quantitative determination of IgG anti-Jo-1 antibodies in human serum. The presence of antibodies, in conjunction with clinical findings and other laboratory tests, is an aid in the diagnosis of idiopathic inflammatory myopathy.

QUANTA Flash Jo-1 Calibrators are intended for use with the QUANTA Flash Jo-1 Reagents for the determination of Ig G anti-Jo-1 antibodies in human serum. Each calibrator establishes a point of reference for the working curve that is used to calculate unit values.

QUANTA Flash Jo-1 Controls are intended for use with the OUANTA Flash Jo-1 Reagents for quality control in the determination of IgG anti-Jo-1 antibodies in human serum.

The QUANTA Flash Jo-1 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 Jo-1 assay utilizes a reagent cartridge format, which is compatible with the BIO-FLASH instrument.

Recombinant Jo-1 antigen is coated onto paramagnetic beads, which is stored in the reagent cartridge as a suspension. When the cartridge is ready to be used for the first time, the entire cartridge is inverted several times to thoroughly mix the reagent cartridge is then loaded onto the BIO-FLASH instrument. Samples are also loaded onto the instrument in sample racks. Serum samples are diluted 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 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 (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 IgG, which is in turn proportional to the amount of anti-Jo-1 antibodies bound to the corresponding beads.

For quantitation, the QUANTA Flash Jo-1 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 Jo-1 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 Jo-1 kit contains the following materials:

One (1) QUANTA Flash Jo-1 Reagent Cartridge

The QUANTA Flash Jo-1 reagent cartridge contains the following reagents for 50 determinations:

• a. Jo-1 coated paramagnetic beads, in a suspension containing buffer, protein stabilizers and preservative.
• b. Assay buffer - colored pink, containing buffer, 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 Jo-1 Calibrators kit contains two vials of Calibrator 1 and two vials of Calibrator 2:

QUANTA Flash Jo-1 Calibrators:

• І QUANTA Flash Jo-1 Calibrator 1: Two (2) barcode labeled tubes containing 0.3 mL prediluted, ready to use reagent. Calibrators contain human antibodies to Jo-1 in buffer, stabilizer and preservative.
• QUANTA Flash Jo-1 Calibrator 2: Two (2) barcode labeled tubes containing 0.3 mL prediluted, ready to use reagent. Calibrators contain human antibodies to Jo-1 in buffer, stabilizer and preservative.

The QUANTA Flash Jo-1 Controls kit contains two vials of Negative Control and two vials of Positive Control:

QUANTA Flash Jo-1 Controls:

• -QUANTA Flash Jo-1 Negative Control: Two (2) barcode labeled tubes containing 0.5 mL, ready to use reagent. Controls contain human antibodies to Jo-1 in buffer, stabilizer and preservative.
• QUANTA Flash Jo-1 Positive Control: Two (2) barcode labeled tubes containing 0.5 mL, ready to use reagent. Controls contain human antibodies to Jo-1 in buffer, stabilizer and preservative.

The provided text describes the analytical and clinical performance characteristics of the QUANTA Flash® Jo-1 chemiluminescent immunoassay. This device is intended for the semi-quantitative determination of IgG anti-Jo-1 antibodies in human serum to aid in the diagnosis of idiopathic inflammatory myopathy.

Here's the breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided document:

Acceptance Criteria and Reported Device Performance

Note: The document provides detailed analytical performance characteristics and clinical performance characteristics. For acceptance criteria, the document explicitly states them for:

• Precision (Total %CV: < 10%)
• Reproducibility (Total %CV: < 15%)
• Linearity (Recovery: 80-120% or ± 4 CU; Slope: 0.9-1.1; R^2: ≥ 0.95)
• Interference (Recovery: 85-115% for samples above cutoff; ± 4 CU for samples below cutoff)
• Lot to Lot Comparison (Between lot %CV: < 10%)
• Sample Stability (90-110% average recovery)
• Reagent Shelf Life (Beads: 85-115% recovery at day 14; Controls & Calibrators: 90-110% recovery at day 14)
• In-use (onboard) Calibrator Stability (Calibrator RLU recovery: 90-110%)
• In-use (onboard) Control Stability (Regression line: 85-115% at run 15)
• Real Time Stability (Results within respective QC ranges/acceptable ranges)

The document primarily focuses on demonstrating that the results achieved meet these pre-defined acceptance criteria, rather than stating all criteria first and then presenting results in a consolidated table for every single point. The tables below compile the key numerical performance metrics against the stated acceptance criteria where available in the document.

Table 1: Acceptance Criteria and Reported Device Performance

Study Details

The provided document describes studies conducted to support the substantial equivalence of the QUANTA Flash® Jo-1 device to a predicate device (FIDIS Connective 10). Primarily, this involves analytical and clinical performance testing for an in vitro diagnostic (IVD) immunoassay, not an AI/ML-driven medical device in the typical sense that would involve image analysis or complex algorithms requiring expert readers for ground truth. Therefore, many of the typical questions for AI/ML devices (e.g., number of experts, adjudication methods, MRMC studies) are not applicable here.

1. Sample size used for the Test Set and Data Provenance:

   • Clinical Validation Cohort / Test Set: 487 characterized samples. This was composed of 206 Idiopathic Inflammatory Myopathy (IIM) patients and 281 control subjects (Systemic Sclerosis, Rheumatoid Arthritis, Systemic Lupus Erythematosus, Septicacaemia, Mixed Connective Tissue Disease, Sjögren's Syndrome).
   • Method Comparison Test Set: 425 samples from the clinical validation study + 26 additional contrived samples (total 451 samples, analyzed using 105 samples within AMR).
   • Reference Range Establishment: 207 subjects (various conditions including autoimmune diseases, infections, and healthy individuals).
   • Expected Values in Normal Population: 400 apparently healthy blood donors (246 females, 154 males, ages 17-60).
   • Data Provenance: The document does not explicitly state the country of origin or if the data was retrospective or prospective. Given the nature of an IVD submission and clinical laboratory studies, it's typically a mix of retrospectively collected well-characterized samples and prospectively run samples in controlled laboratory settings for performance evaluation.

2. Number of Experts used to establish the ground truth for the test set and the qualifications of those experts:

   • Not Applicable in the traditional sense for this IVD immunoassay. Ground truth for this assay is linked to the presence or absence of specific autoantibodies (anti-Jo-1) as determined by clinical diagnosis of Idiopathic Inflammatory Myopathy (IIM) and other clinical findings, along with the performance of the predicate device. The samples used are described as "characterized samples," meaning their disease status would have been established through standard clinical diagnostic procedures, not necessarily through a panel of expert "readers" establishing ground truth in the way it's done for imaging AI.

3. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

   • Not Applicable. As this is an IVD immunoassay for antibody determination, not an AI/ML system requiring reader adjudication for image interpretation.

4. 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 not an AI/ML device designed to assist human readers in interpretation. It's a laboratory test system producing a biochemical result.

5. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

   • Applicable, effectively YES for the device test. The "standalone" performance here refers to the analytical and clinical performance of the assay itself (device + instrument) without human interpretive input beyond following the assay procedure and reading quantitative results. The entire analytical performance section (Precision, LoD, Linearity, Interference, etc.) and clinical performance (Sensitivity, Specificity) demonstrate the standalone performance of the assay. The method comparison with the predicate device also serves this purpose.

6. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

   • Clinical Diagnosis / Clinical Findings / Well-Characterized Samples: For clinical performance, the ground truth was based on the clinical diagnosis of Idiopathic Inflammatory Myopathy (IIM) and other related conditions. The samples were described as "characterized samples," implying their disease status was established through established clinical criteria, which would involve a combination of clinical findings, potentially pathology (e.g., muscle biopsy for myopathy), and other laboratory tests. For the analytical studies, ground truth for some samples was "contrived" by diluting known positive samples to create a range of concentrations.

7. The sample size for the training set:

   • Not provided/Applicable in the AI/ML sense. This is an immunoassay, not an AI/ML model trained on a dataset. The "training" for such a device occurs during its development and optimization, which would involve many samples, but they are not typically referred to as a "training set" in the context of an AI/ML model. The "Master Curve Standards" are used for manufacturing and calibration, but not as a machine learning training set.

8. How the ground truth for the training set was established:

   • Not Applicable in the AI/ML sense. For an immunoassay, the "ground truth" for calibrators and controls is established through rigorous value assignment procedures, often traceable to in-house primary standards and confirmed through extensive testing (e.g., "trial dilutions on small scale," "tested on at least two instruments, on at least two lots of reagent cartridge, in replicates of 10"). The "standards" themselves are assigned values through a manufacturing process.

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