(62 days)
Reagents: For the direct, quantitative determination of low-density lipoprotein cholesterol (LDL-C) in human serum or plasma. Calibrator: For the calibration of the N-geneous® LDL-ST Cholesterol assay in serum or plasma. Controls: To monitor the performance of the Genzyme Direct LDL Cholesterol, N-geneous® LDL Cholesterol and N-geneous® LDL-ST Cholesterol Reagents.
The Genzyme N-geneous® LDL-ST Cholesterol Reagent is a two-reagent homogeneous method for the direct quantitative determination of low density lipoprotein cholesterol (LDL-C) in human serum and plasma. This method is applicable to Olympus two-reagent Chemistry Analyzers and does not require any off-line pretreatment or centrifugation steps. The principle of the test is based upon a unique detergent which selectively solubilizes only the non-LDL lipoproteins, allowing them to be removed by cholesterol enzymes prior to the LDL cholesterol reaction. The LDL particles remain intact. The hydrogen peroxide produced by the reaction of the enzymes with the released cholesterol is consumed by a peroxidase reaction with 4-aminoantipyrine, yielding a colorless product. A second detergent, capable of releasing LDL cholesterol molecules, is added. The enzyme reaction with LDL cholesterol in the presence of the coupler produces color which is proportional to the amount of LDL cholesterol in the sample.
The Genzyme N-geneous® LDL-ST Cholesterol Reagent is a two-reagent homogeneous method for the direct quantitative determination of low density lipoprotein cholesterol (LDL-C) in human serum and plasma. The study aimed to demonstrate the substantial equivalence of the Genzyme N-geneous® LDL-ST Cholesterol Reagent to the N-geneous® LDL Cholesterol Reagents and the ß-Quantification methods.
Acceptance Criteria and Reported Device Performance:
The document does not explicitly state pre-defined acceptance criteria values for the slope, intercept, or correlation coefficient. However, the study results are presented for comparison to the predicate devices. The implicit acceptance criteria are that the performance metrics of the N-geneous® LDL-ST on the Olympus AU600 are comparable to those of the predicate methods (ß-Quantification and N-geneous® LDL on Hitachi 911).
| Metric | Acceptance Criteria (Implicit - based on predicate performance) | Reported Performance (N-geneous® LDL-ST vs. ß-Quantification) | Reported Performance (N-geneous® LDL-ST vs. N-geneous® LDL) |
|---|---|---|---|
| Slope | Expected to be close to 1 | 1.08 | 1.02 |
| Intercept (mg/dL) | Expected to be close to 0 | -8.7 | -1.7 |
| Correlation Coefficient (r) | Expected to be close to 1 | 0.969 | 0.990 |
| Mean Difference (mg/dL) | Expected to be close to 0 | 0.6 | 0.3 |
| Mean Percent Difference (%) | Expected to be close to 0 | -0.1 | 0.1 |
| Within-Run Precision %CV (Low) | Not explicitly stated, lower is better | 1.4 | N/A |
| Within-Run Precision %CV (High) | Not explicitly stated, lower is better | 0.8 | N/A |
| Between-Run Precision %CV (Low) | Not explicitly stated, lower is better | 2.1 | N/A |
| Between-Run Precision %CV (High) | Not explicitly stated, lower is better | 2.7 | N/A |
Device Performance Study Details:
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Sample Size and Data Provenance:
- Test Set for comparative studies:
- 77 serum samples used for comparison between N-geneous® LDL-ST and N-geneous® LDL.
- 62 of these 77 samples had sufficient volume for comparison with the ß-Quantification method.
- Test Set for precision studies: 20 replicates for each of the "Low" and "High" controls for both within-run and between-run precision.
- Data Provenance: The study was conducted at Genzyme Corporation. The country of origin of the samples is not specified, but the context implies a retrospective analysis of collected human serum samples.
- Test Set for comparative studies:
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Number of Experts and Qualifications: Not applicable. This is a quantitative chemical assay, not an imaging or diagnostic device requiring expert interpretation for ground truth.
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Adjudication Method: Not applicable for a quantitative chemical assay.
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Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study: Not applicable. This is a chemical assay, not a device requiring human reader interpretation in a clinical setting.
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Standalone (Algorithm Only) Performance: The performance reported is the standalone performance of the Genzyme N-geneous® LDL-ST Cholesterol Reagent on the Olympus AU600 Analyzer. There is no human-in-the-loop component.
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Type of Ground Truth Used:
- For the comparative studies, the ground truth was established by two reference laboratory methods:
- ß-Quantification method (considered a gold standard for LDL-C measurement).
- N-geneous® LDL Cholesterol Reagent (a previous version/predicate device from Genzyme).
- For the precision studies, the ground truth was based on the measured mean values of Genzyme Desirable and Risk controls.
- For the comparative studies, the ground truth was established by two reference laboratory methods:
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Sample Size for Training Set: Not applicable. This is a chemical reagent, not a machine learning algorithm that requires a training set in the conventional sense. The development of the reagent itself would involve R&D and analytical optimization, but this document does not detail a "training set" for a predictive model.
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How Ground Truth for Training Set was Established: Not applicable, as there is no specified training set for a machine learning model. The chemical formulation and methodology of the reagent are based on established biochemical principles and experimental validation during its development.
§ 862.1475 Lipoprotein test system.
(a)
Identification. A lipoprotein test system is a device intended to measure lipoprotein in serum and plasma. Lipoprotein measurements are used in the diagnosis and treatment of lipid disorders (such as diabetes mellitus), atherosclerosis, and various liver and renal diseases.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 862.9.