(177 days)
N Latex HCY: In vitro diagnostic reagents for the quantitative determination of total homocysteine (HCY) in human serum, heparinized plasma and EDTA plasma by means of particle-enhanced immunonephelometry on the BN™ II and BN ProSpec® Systems. The device can assist in the diagnosis and treatment of patients suspected of having hyperhomocysteinemia and homocystinuria.
N Protein Standard SL: Establishment of reference curves for the determination of IgG, IgG14, IgA, IgM, IgE, C3c, C4, transferrin, albumin, α-antitrypsin, α--macroglobulin, haptoglobin, α -- acid glycoprotein, prealbumin, hemopexin, ceruloplasmin, RbP, (g/L-chain lambda & kappa, soluble transferrin receptor, ferritin, ß2-microglobulin, total protein and homocysteine by immunonephelometry with BN™ Systems.
N/T Protein Control SL/L, M and H: N/T Protein Controls SL/L, M, and H are for use as accuracy and precision assayed controls in the determination of the following human serum proteins by immunonephelometry with BN™ Systems: IgG, IgGr.4, IgM, C3c, C4, transferrin, albumin, αγ-antitrypsin, α₂-macroglobulin, haptoglobin, α - acid glycoprotein, prealbumin, hemopexin, ceruloplasmin, RbP, Ig/L-chain lamhda & Rogioa, βmicroglobulin, soluble transferrin receptor, ferritin, IgE, total protein and homocysteine.
Bound homocysteine in the sample is reduced to free homocysteine by the action of dithiothreitol, and converted enzymatically to S-adenosyl-homocysteine (SAH) in the next step. Conjugated S-adenosyl-cysteine (SAC), added at the onset of the reaction, competes with the SAH in the sample for bonding by anti-SAH antibodies bound to polystyrene particles. In the presence of SAH, there is either no aggregation or a weaker aggregation of particles. In the absence of SAH in the sample, an aggregation of the polystyrene particles by the conjugated SAC occurs. The higher the SAH content of the reaction mixture is, the smaller the scattered light signal. The result is evaluated by comparison with a standard of known concentration.
Here's a breakdown of the acceptance criteria and study details for the N Latex HCY device, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Correlation Coefficient: Not explicitly stated as a formal "acceptance criteria" but implied by the comparison to the predicate device. | 0.99 (Correlation Coefficient with Abbott IMx HCY assay) |
| Slope: Not explicitly stated as a formal "acceptance criteria" but implied by the comparison to the predicate device. | 0.97 (Slope against Abbott IMx HCY assay) |
| Intercept: Not explicitly stated as a formal "acceptance criteria" but implied by the comparison to the predicate device. | 0.06 (Intercept against Abbott IMx HCY assay) |
Note: The document states that the N Latex HCY assay was compared to the Abbott IMx HCY assay, and the regression analysis results (slope, intercept, and correlation coefficient) are presented. The implicit acceptance criteria here is that the N Latex HCY assay demonstrates strong agreement and equivalence with the legally marketed predicate device. A correlation coefficient of 0.99, a slope close to 1, and an intercept close to 0 typically indicate excellent agreement between two assays.
Study Details
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Sample size used for the test set and the data provenance:
- Sample Size: 73 plasma samples.
- Data Provenance: Not specified within the provided text (e.g., country of origin, retrospective or prospective).
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable as this is a quantitative chemical assay being compared to a predicate device, not, for example, an image-based diagnostic relying on expert reads. The "ground truth" for the test set is established by the measurements from the predicate device (Abbott IMx HCY assay).
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Adjudication method for the test set:
- Not applicable. The study involves a direct comparison of quantitative results between the candidate device and a predicate device, not an expert panel adjudication.
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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. This is a comparison study of a diagnostic assay (N Latex HCY) against a predicate device (Abbott IMx Homocysteine Assay) and does not involve human readers or AI assistance in the context of MRMC studies.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, the study describes the standalone performance of the N Latex HCY device by comparing its quantitative results directly to those of the Abbott IMx HCY assay. The device itself is an automated in vitro diagnostic reagent system.
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The type of ground truth used:
- The "ground truth" in this context is the results obtained from the legally marketed Abbott IMx Homocysteine Assay (K992858), which serves as the reference method for establishing substantial equivalence.
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The sample size for the training set:
- Not applicable. This document describes a clinical comparative study for substantial equivalence, not the development or training of an algorithm via a training set. The N Latex HCY system is a reagent and instrument-based assay, not an AI/ML algorithm that requires a separate training set.
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How the ground truth for the training set was established:
- Not applicable, as there is no mention of a training set for an AI/ML algorithm.
§ 862.1377 Urinary homocystine (nonquantitative) test system.
(a)
Identification. A urinary homocystine (nonquantitative) test system is a device intended to identify homocystine (an analogue of the amino acid cystine) in urine. The identification of urinary homocystine is used in the diagnosis and treatment of homocystinuria (homosystine in urine), a heritable metabolic disorder which may cause mental retardation.(b)
Classification. Class II.