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The LIAISON® Anti-HAV assay is an in vitro chemiluminescent immunoassay intended for the qualitative detection of total antibodies to hepatitis A (anti-HAV) in human serum and sodium heparin plasma samples using the LIAISON® Analyzer family. The assay is indicated as an aid in the laboratory diagnosis of current or previous HAV infections in conjunction with other serological and clinical information and to determine the presponse to HAV in vaccine recipients.

The assay is not intended for screening blood or solid or soft tissue donors.

The method for qualitative determination of anti-HAV is a competitive sandwich chemiluminescence immunoassay (CLIA) based on neutralization. The assay uses magnetic particles (solid phase) coated with IqG antibodies to HAV (mouse monoclonal), and a mouse monoclonal anti-HAV antibody conjugate linked to an isoluminol derivative (isoluminol-antibody conjuqate). The first incubation step consists of adding the HAV antigen to calibrators, samples or controls, during which anti-HAV present in calibrators, samples or controls binds to a fixed and limited amount of HAV. thus forming an HAV-anti-HAV immune complex. After this step the second incubation follows and it involves addition of magnetic microparticles and conjugate into the cuvette, during which the antibody conjugate and the solid-phase antibody compete with anti-HAV present in the specimen for HAV. This allows the conjugate to bind to the solid phase and to form a sandwich. If all HAV added is sequestered in an HAV-anti-HAV immune complex during the first incubation, no sandwich is formed during the second incubation. After the second incubation, the unbound material is removed with a wash cycle. Subsequently, the starter reagents are added and a flash chemiluminescence reaction is thus induced. The light signal, and hence the amount of isoluminol-antibody conjugate, is measured by a photomultiplier as relative light units (RLU) and is inversely indicative of anti-HAV present in calibrators, samples or controls.

Here's an analysis of the provided text regarding the DiaSorin Inc. LIAISON® Anti-HAV device, outlining acceptance criteria and study details:

Acceptance Criteria and Device Performance

The provided document describes two main performance studies: a Method Comparison study and a Reproducibility study. The "acceptance criteria" are implied by the reported agreement percentages and coefficient of variation (%CV) values, which are generally expected to be high for agreement and low for variation in diagnostic assays.

Table of Acceptance Criteria and Reported Device Performance

Study Details for LIAISON® Anti-HAV

Here's a breakdown of the specific information requested, based on the provided text:

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

• Method Comparison Test Set: 100 frozen serum samples.

• Data Provenance: Samples were "either selected or prepared by DiaSorin Inc." The text does not explicitly state the country of origin or if the samples were retrospective or prospective, but the selection/preparation by the manufacturer suggests a controlled, potentially retrospective or spiked sample set rather than a purely prospective real-world patient cohort. The testing was performed at "2 external sites and at DiaSorin Inc."

• Reproducibility Study Test Set: A coded precision panel consisting of seven (7) serum specimens manufactured by DiaSorin S.p.A. and two (2) kit controls (a positive and negative from a single control lot). Each sample was run with 4 replicates per day for 12 days at each of the 3 sites, totaling 144 replicates per sample (4 replicates/day * 12 days * 3 sites) for both samples and controls.

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

The studies described are for an in vitro diagnostic (IVD) immunoassay, not an imaging device or AI-driven diagnostic that typically involves human expert interpretation for ground truth. Therefore, no human experts were used to establish ground truth in the traditional sense for these performance studies.

• In the method comparison study, the ground truth for samples was based on the results from a predicate device (LIAISON® Anti-HAV, Reference K082049).
• In the reproducibility study, the "ground truth" for the precision panel samples would be their known or assigned concentration/status based on their manufacturing and characterization, against which the assay's consistency is measured. The text doesn't specify how these concentrations were established, but it would typically be through reference methods or rigorous characterization during manufacturing.

4. Adjudication Method for the Test Set

Given that these are performance studies for an in vitro diagnostic where comparison is primarily against a predicate device or known sample characteristics, no human adjudication method (e.g., 2+1, 3+1) was mentioned or would typically be applicable. The "adjudication" is effectively the direct comparison of results between the new device and the predicate device or the statistical analysis of quantitative measurements against expected values (for reproducibility).

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. MRMC studies are typically performed for medical imaging or AI diagnostics where multiple human readers interpret cases and their performance is compared with and without AI assistance. This document describes an in vitro diagnostic assay that determines the presence of antibodies in serum/plasma, not a technology that human readers interpret.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

The LIAISON® Anti-HAV assay itself is a standalone in vitro diagnostic device, meaning its performance is evaluated based on its own output (chemiluminescence signal leading to qualitative detection of antibodies) without direct human interpretation of complex patterns or images. The "algorithm" in this context refers to the assay's chemical and instrumental process, which produces results independently. The provided studies directly assess this standalone performance (e.g., agreement with a predicate, and reproducibility).

7. The Type of Ground Truth Used

• Method Comparison Study: The ground truth for the test set was established by the predicate device (LIAISON® Anti-HAV, Reference K082049) results. This is a common practice for demonstrating substantial equivalence for IVDs.
• Reproducibility Study: The ground truth, in terms of expected values for precision, was based on the known characteristics of the manufactured serum specimens and kit controls. This is not "expert consensus" or "pathology" but rather scientifically characterized samples.

8. The Sample Size for the Training Set

The document does not specify a training set sample size. This is expected because the LIAISON® Anti-HAV assay is a chemiluminescent immunoassay, which is a traditional laboratory diagnostic method based on biochemical reactions, not a machine learning or AI algorithm that requires a "training set" in the context of model development. The development of such an assay involves extensive R&D, reagent optimization, and analytical validation but not a "training set" in the computational sense.

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

Since there is no "training set" in the AI/ML sense, this question is not applicable based on the provided information. The development of the assay would have relied on established scientific principles, method validation, and characterization of reagents and controls.

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