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The Aptiva Celiac Disease IgA Reagent is an immunoassay utilizing particle-based multi-analyte technology for the semiquantitative determination of anti-tissue transglutaminase IgA autoantibodies and anti-deamidated gliadin peptide IgA autoantibodies in human serum. The presence of these autoantibodies, in conjunction with clinical findings and other laboratory tests, is an aid in the diagnosis of celiac disease and dermatitis herpetiformis. The Aptiva Celiac Disease IgA Reagent is intended for use with the Inova Diagnostics Aptiva System.

The Aptiva Celiac Disease IgA reagent utilizes particle based multi-analyte technology (PMAT) in a cartridge format. Each analyte (tissue transglutaminase [tTG] and deamidated gliadin peptide [DGP]) in the Aptiva Celiac Disease IgA reagent is a solid phase immunoassay utilizing fluorescent microparticles. This technology allows each of the two analytes, along with a human IgA capture antibody (IgA Control Microparticle), to be coated onto three uniquely recognizable paramagnetic microparticles, which are combined into one tube.

The Aptiva instrument is a fully automated, random access analyzer. This platform is a closed system with continuous load and random-access capabilities that processes the samples, runs the reagent and reports results. It includes liquid handling hardware, optical module (OM), and integrated computer with proprietary software and touch screen user interface.

The two analyte microparticles, along with the control microparticle, are stored in the reagent cartridge under conditions that preserve the proteins in their reactive states. When the assay cartridge is ready to be used for the first time, the reagent tube seals are pierced using the cartridge lid. The reagent cartridge is then loaded onto the Aptiva instrument, where the microparticles are automatically rehydrated using buffer located within the cartridge.

A patient's serum is diluted 1:46 with Aptiva system rinse by the instrument in a disposable cuvette. A small amount of the diluted sample is combined with assay buffer and the microparticle suspension in a second cuvette, and mixed (final serum dilution: 1:230). This reaction cuvette is incubated for 9 ½ minutes at 37°C. The cuvette is then exposed to a small magnet that holds the microparticles in place. The liquid is aspirated, and the microparticles are resuspended as system rinse is added to the cuvette and the magnet is removed. This wash cycle is repeated one more time. During the third wash, no system rinse is added after the aspiration step. After the third wash, phycoerythrin conjugated polyclonal anti-human IgA (known as PE Tracer IgA) is added to the microparticles in the cuvette, and mixed. Again, the cuvette is incubated for 9 ½ minutes at 37℃. Three wash steps, as described above, are performed on the microparticles. Following the wash steps, the microparticles are transferred to the of the instrument, where a charge coupled device (CCD) camera takes multiple images in order to identify and count the three unique microparticle regions, as well as determine the amount of conjugate on the microparticles. A third particle, coated with goat antibodies, is present in the reagent as a control to flag low concentrations of IgA in the sample as an assay verification step. The median fluorescent intensity (MFI) is proportional to the amount of PE Tracer that is bound to the human IgA, which is proportional to the amount of IgA antibodies bound to the corresponding microparticle regions.

For quantitation, the DGP IgA and tTG IgA assays (together as part of the Aptiva Celiac Disease IgA Reagent) each utilizes a predefined lot specific Master Curve that is uploaded onto the instrument through the reagent cartridge RFID tag. Every new lot of reagent cartridge must be calibrated before first use with the reagent specific calibrators. Based on the results obtained with the calibrators included in the Aptiva Celiac Disease IgA Calibrator kit (sold separately), an instrument specific Working Curve is created for each assay, which is used to calculate reported fluorescent light units (FLU) from the median fluorescent intensity (MFI) instrument signal obtained for each sample, on each of the two assays within the reagent.

Aptiva Celiac Disease IgA Calibrators and Aptiva Celiac Disease IgA Controls are sold separately.

The Aptiva Celiac Disease IgA Reagent kit contains the following materials:

One (1) Aptiva Celiac Disease IgA Reagent Cartridge, containing the following reagents for 250 determinations:

• a. Aptiva Celiac IgA microparticle containing 3 unique microparticle regions coated with recombinant tissue transglutaminase, deamidated gliadin peptide, or goat anti-human IgA antibody.
• b. Assay buffer - colored pink, containing protein stabilizers and preservatives.
• PE Tracer IgA phycoerythrin (PE) labeled anti-human IgA antibody, containing buffer, C. protein stabilizers and preservative.
• d. Rehydration Buffer - containing protein stabilizers and preservatives.

The provided text is a 510(k) Summary for the Aptiva Celiac Disease IgA Reagent, an in vitro diagnostic device. It describes the analytical and clinical performance of the device to demonstrate its substantial equivalence to predicate devices. It does not describe an AI/ML-based device, a comparative effectiveness study with human readers, or the establishment of ground truth by expert consensus. Therefore, most of the requested information cannot be extracted from this document as it pertains to AI/ML device studies.

However, I can extract the acceptance criteria and reported performance for analytical aspects of this specific in vitro diagnostic device, as well as details regarding sample size, data provenance, and the type of ground truth used for performance evaluation.

Acceptance Criteria and Reported Device Performance

The device under review is an in vitro diagnostic (IVD) test, not an AI/ML-based medical imaging device. As such, the acceptance criteria and performance evaluation are based on typical analytical validation parameters for immunological assays, such as precision, limit of detection, linearity, interference, and clinical sensitivity/specificity against established reference methods or patient diagnoses.

Table of Acceptance Criteria and Reported Device Performance:

Study Details:

1. Sample sizes used for the test set and data provenance:

   • Precision: 9 samples for DGP IgA, 10 samples for tTG IgA (run in duplicates, twice a day, for 20 days).
   • Reproducibility (Between Sites): 7 samples for DGP IgA and 6 samples for tTG IgA.
   • Reproducibility (Between Lots): 6 samples for DGP IgA and 6 samples for tTG IgA.
   • LoB, LoD, LoQ:
     • LoB: 8 blank samples. For each assay (DGP IgA & tTG IgA), on two reagent lots, run in replicates of 5, once per day for 3 days (120 data points per lot).
     • LoD & LoQ: 4 low-level samples for each assay (DGP IgA & tTG IgA). For each assay, on two reagent lots, run in replicates of 5, twice per day for 3 days (120 data points per assay per lot).
   • Linearity: 4 human serum samples for each assay, serially diluted and assayed in duplicates.
   • Interference: 3 human serum specimens (one positive, one near cutoff, one negative).
   • Sample Stability: 8 test samples for DGP IgA, 6 test samples for tTG IgA.
   • Clinical Performance (Validation Set): A total of 495 characterized samples.
     • 171 samples from celiac disease patients.
     • 34 dermatitis herpetiformis patients.
     • 290 control samples from patients with various types of autoimmune and infectious diseases (e.g., Rheumatoid Arthritis, Ulcerative Colitis, Crohn's Disease, Hepatitis C/B, Syphilis, Sjögren's Syndrome, Systemic Sclerosis, Autoimmune Gastritis, HIV, Systemic Lupus Erythematosus, Epstein-Barr Virus).
     • The document does not explicitly state the country of origin but implies data collection from clinical settings. It describes the use of "characterized samples" and "diagnosed celiac disease (CD) patient specimens," indicating that this was likely a retrospective collection of samples with established diagnoses.
   • Expected Values (Normal Population): 120 apparently healthy blood donors.
   • Method Comparison: All 495 samples from the clinical validation study were also used for method comparison against the predicate devices.

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

   • This is an IVD device, not an AI/ML imaging device. The "ground truth" for the test set (clinical validation cohort) was based on patient diagnoses (e.g., "celiac disease patients," "dermatitis herpetiformis," "control samples from patients with various types of autoimmune and infectious diseases"). Therefore, the ground truth was established by clinical diagnosis, which would typically be made by medical doctors/specialists based on relevant clinical findings and other laboratory tests, rather than by a specific number of experts reviewing image data. The document does not specify the number or qualifications of clinicians involved in establishing these diagnoses.

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

   • Not applicable, as this is an IVD test assessing biochemical markers, not an imaging device requiring expert adjudication of interpretations. The "ground truth" is the established clinical diagnosis of the patient.

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 imaging device, and no MRMC study was performed or is relevant to this type of IVD test.

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

   • The "standalone performance" of this device is represented by its analytical performance characteristics (precision, linearity, LoD, etc.) and its clinical sensitivity and specificity, where the device provides a quantitative result (FLU) to aid in diagnosis. There is no "human-in-the-loop" aspect to the performance of the device itself (it's an automated analyzer), though clinicians interpret its results in conjunction with other clinical findings.

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

   • The primary ground truth for the clinical performance evaluation was established clinical diagnoses of patients ("celiac disease patients," "dermatitis herpetiformis patients," and "control samples from patients with various types of autoimmune and infectious diseases"). This implicitly relies on a combination of clinical findings, potentially other laboratory tests, and possibly biopsy results (pathology) for definitive diagnoses like celiac disease. The document states, "The presence of these autoantibodies, in conjunction with clinical findings and other laboratory tests, is an aid in the diagnosis of celiac disease and dermatitis herpetiformis."

7. The sample size for the training set:

   • This device is an immunoassay (particle-based multi-analyte technology) operating on predefined Master Curves and calibrations. It does not use a "training set" in the sense of machine learning algorithms. The Master Curves and calibrations are established by the manufacturer through runs of precisely quantified standards (e.g., "in-house Master Curve Standards," "reagent specific calibrators"). The section "Quantitation and units of measure" describes how these curves are generated. For example, "Aptiva Celiac Disease IgA Master Curve Standards - DGP IgA" lists 6 standards with assigned FLU values. While these could be seen as "training data" for the device's internal quantitation function, it's not a machine learning model.

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

   • Not applicable in an AI/ML context. For this IVD device, the "ground truth" for its internal calibration (analogous to a training set for an AI model) is based on manufacturer-defined standards with assigned known values ("in-house Master Curve Standards with assigned FLU values"). These standards are run multiple times to generate the 4-parameter logistic (4PL) curve that quantifies the analyte concentration.

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