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For in-vitro diagnostic use. For the quantitative determination of gamma glutamyltransferase in serum.

Elevated serum gamma glutamyltransferase (GGT) is found in chronic alcoholism, diabetes, certain neurological disorders, and all forms of liver disease. It is more sensitive than alkaline phosphatase, the transaminases, and leucine aminopeptidase (LAP) in detecting obstructive jaundice, cholangitis, and cholecystitis; its rise occurs earlier than these other enzymes and persists longer. Moderate increases are seen with infectious hepatitis, and normal levels are seen in skeletal disease. Serum GGT levels can therefore be used to differentiate skeletal or hepatobiliary disease.

The intended use is the same as the predicate device.

The method is based on the reaction wherein gamyl glutamyltransferase catalyzes the transfer of the glutamyl group from L-g-glutamyl-3-carboxy-4-nitroanilide to glycylglycine with the formation of g-glutamylglycylglycine and 5-amino-2-nitrobenzoate. The rate of increase of 5-amino-2-nitrobenzene, which absorbs light at 405 nM. is proportional to the gamma glutamyltransferase activity in the sample.

1. Acceptance Criteria and Reported Device Performance:

2. Sample Size and Data Provenance:

The provided text focuses on the performance characteristics of the device and its comparison to a predicate device. It does not explicitly state the sample sizes used for the testing of linearity, precision, sensitivity, or interference studies. The data provenance is also not specified (e.g., country of origin, retrospective or prospective).

3. Number and Qualifications of Experts for Ground Truth:

Not applicable. This is an in vitro diagnostic device for quantitative determination of an enzyme, not an imaging or diagnostic AI tool that requires expert interpretation for ground truth establishment.

4. Adjudication Method:

Not applicable. See point 3.

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

Not applicable. This is not a comparative effectiveness study involving human readers and AI for diagnostic tasks. It's a comparison of an in vitro diagnostic assay to a predicate device.

6. Standalone Performance:

Yes, the provided data describes the standalone performance of the Data Medical Associates device through various non-clinical tests (linearity, precision, shelf-life, sensitivity, interferences, expected values). This data represents the performance of the algorithm/reagent without human intervention in the measurement process.

7. Type of Ground Truth Used:

The "ground truth" for the performance characteristics described here would be established through laboratory reference methods, calibrated standards, and known concentrations of analytes.

• Linearity: Determined by assaying samples with known, varying concentrations of GGT and ensuring the measured values are proportional.
• Precision: Determined by repeated measurements of samples with known GGT concentrations.
• Sensitivity: Determined by measuring the lowest detectable concentration of GGT using established methods.
• Interferences: Determined by spiking samples with known concentrations of potential interfering substances (bilirubin, hemoglobin, triglycerides) and observing their effect on GGT measurements compared to unspiked controls.
• Expected Values: Established through studies of a healthy reference population using validated methods.

8. Sample Size for the Training Set:

Not applicable. This is not a machine learning or AI-driven device in the sense of requiring a "training set." The device is a chemical reagent method.

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

Not applicable. See point 8.

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