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The LIAISON® Aldosterone assay uses chemiluminescent immunoassay (CLIA) technology and is intended for the quantitative determination of Aldosterone in human serum. EDTA plasma and treated urine samples. Aldosterone measurements are intended for use in the diagnosis and treatment of primary aldosteronism (a disorder caused by excessive secretion of aldosterone by the adrenal gland), hypertension caused by primary aldosteronism, selective hypoaldosteronism, edematous states and other conditions of electrolyte imbalance. The test has to be performed on the LIAISON® Analyzer.

The DiaSorin LIAISON® Aldosterone Control Set is intended for use as assayed quality control samples to monitor the accuracy of the DiaSorin LIAISON® Aldosterone assay on the LIAISON® Analyzer.

The DiaSorin LIAISON® Aldosterone Calibration Verifiers are assayed quality control materials intended for the quantitative verification of calibration and reportable range of the LIAISON® Aldosterone assay when performed on the LIAISON® Analyzer.

The LIAISON® Aldosterone assay is a competitive modified 2 step chemiluminescent assay that uses sheep monoclonal antibody for capture of the Aldosterone molecule. Results are determined by a 2 point calibration conversion of the master curve to a working curve. The light signal is measured by a photomultiplier as relative light units (RLU) and is inversely proportional to the concentration of aldosterone present in the calibrators, controls or samples.

Here's a breakdown of the acceptance criteria and study details for the LIAISON® Aldosterone assay, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly present a table of "acceptance criteria" with specific pass/fail thresholds for the LIAISON® Aldosterone assay. However, it provides performance data that would implicitly be compared against desired clinical or analytical requirements. Below is a table summarizing the reported performance, which serves as evidence of the device meeting its intended analytical characteristics.

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

• Method Comparison Test Set:

  • Serum: 155 samples (144 included in analysis as 11 were below measuring range).
  • Urine: 106 samples (104 included in analysis as 2 were above measuring range).
  • Data Provenance: Samples were "collected from apparently healthy individuals." A portion (approximately 15%) were spiked with aldosterone to span the measuring range. The study was conducted using the LIAISON® Aldosterone assay and the predicate RIA assay. Although not explicitly stated, the context of a 510(k) submission strongly implies these are likely prospective or retrospective clinical samples (for the healthy individuals) used in a controlled laboratory setting, potentially from the region where DiaSorin Inc. operates (Stillwater, MN, USA), though this is not explicitly stated.

• LoB/LoD/LoQ Test Set: Not specified, but generally refers to a set of blank and low-concentration samples. The determination was performed according to CLSI EP17-A2.

• Reference Range/Expected Values Test Set:

  • Serum and EDTA Plasma: 126 apparently healthy subjects.
  • Urine (24 hour): 91 individuals.
  • Data Provenance: Samples collected from apparently healthy subjects aged 21-65 years with normal blood pressure and normal fasting glucose levels. These are prospectively collected clinical samples following specific patient preparation protocols (fasting, upright/supine positions, 24-hour collection). No specific country of origin is mentioned.

• Reproducibility/Precision Test Set:

  • Panel: 6 frozen serum samples and 3 frozen urine samples.
  • Controls: 2 levels of controls.
  • Data Provenance: A "coded panel" prepared by DiaSorin Inc. Tested at "DiaSorin Inc. and 2 external sites." This indicates laboratory-prepared samples tested in a multi-site, controlled study.

• Dilution Linearity Test Set: Not specified, but samples of "each sample type" (serum, EDTA plasma, urine) were diluted. This implies laboratory-prepared or clinical samples serially diluted.

• Interfering Substances & Cross-Reactivity Test Set: Not specified, but involved samples spiked with various substances at defined concentrations. These are laboratory-prepared samples.

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

This type of immunoassay (measuring a specific analyte concentration) does not typically involve human experts to establish "ground truth" in the same way an imaging or diagnostic AI does. The "ground truth" for this device's performance studies is established by:

• Predicate Device: For method comparison, the Siemens Coat-A-Count® Aldosterone RIA assay (K831178) served as the reference standard. This is a previously cleared and established clinical assay, representing the accepted "truth" for aldosteronemeasurements at the time.
• Known Concentrations: For studies like LoB/LoD/LoQ, Dilution Linearity, Interfering Substances, and Cross-Reactivity, the "ground truth" is based on known, prepared concentrations of the analyte and potential interfering/cross-reacting substances. These are analytically derived standards.
• Statistical Analysis: CLSI guidelines (EP9-A2, EP17-A2, EP6-A) provide the statistical and methodological frameworks for establishing these analytical performance characteristics.

Therefore, no information about human experts (e.g., radiologists) with specific qualifications or experience in establishing ground truth for this analytical device is provided or expected.

4. Adjudication Method for the Test Set

No adjudication method (e.g., 2+1, 3+1) is mentioned or applicable. As a quantitative immunoassay, the output is a numerical concentration. The comparison is between the new device's numerical result and the predicate device's numerical result (or known spike concentrations), not subjective interpretations requiring adjudicated consensus.

5. 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

No MRMC comparative effectiveness study was performed or is applicable to this type of in vitro diagnostic device (immunoassay). This device directly measures an analyte concentration, and there is no "human reader" involved in interpreting its output in the context of an MRMC study.

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

Yes, the studies presented (Method Comparison, LoB/LoD/LoQ, Precision, Dilution Linearity, Interfering Substances, Cross-Reactivity) all represent standalone performance of the LIAISON® Aldosterone assay. The device provides a quantitative measurement directly, without human interpretation for the primary output. Its performance is evaluated purely on its analytical accuracy, precision, and specificity against established methods or known standards.

7. The Type of Ground Truth Used

The ground truth used in these studies consists of:

• Predicate Device Measurements: For method comparison, the results from the Siemens Coat-A-Count® Aldosterone RIA assay served as the comparative ground truth.
• Known/Expected Concentrations: For LoB/LoD/LoQ determinations, dilution linearity, interference, and cross-reactivity studies, the ground truth was based on analytically derived and known concentrations of aldosterone or other substances.
• Biological Referencing: For the reference range studies, the "ground truth" was established by measuring aldosterone levels in clinically defined healthy populations under controlled conditions.

8. The Sample Size for the Training Set

No information about a "training set" is provided. This type of immunoassay (CLIA technology) is a chemical and biological measurement system, not a machine learning or AI algorithm that typically has a distinct training phase requiring a training dataset. The device's operational parameters (e.g., calibration, reagent concentrations, reaction times) are established through analytical development and optimization, rather than machine learning training.

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

As there is no "training set" in the context of a machine learning algorithm, this question is not applicable. The device's functionality is based on its underlying chemical and immunoassay principles, which are developed and validated through a series of analytical studies as described in the performance data section, rather than through a machine learning training process.

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