(50 days)
IMMULITE 2000 Vitamin B12 is for in vitro diagnostic use with the IMMULITE 2000 Analyzer for the quantitative measurement of vitamin B12 in serum or heparinized plasma, as an aid in clinical diagnosis and treatment of anemia.
IMMULITE® 2000 Vitamin B12 is a clinical device for use with the IMMULITE 2000 Automated Immunoassay Analyzer. IMMULITE® and IMMULITE® 2000 Vitamin B12 are chemiluminescent immunoassays. The technology in DPC's IMMULITE® 2000 Vitamin B12 is a unique combination of technologies employed in previously cleared and commercially marketed DPC products. The IMMULITE 2000 Vitamin B12 assay begins with a one-cycle sample treatment of patient serum or plasma with dithiothreitol (DTT) and a sodium hydroxide/potassium cyanide solution (NaOH/KCN) in a reaction tube containing no bead. After a 30-minute incubation, the treated sample is transferred to a second reaction tube containing a vitamin B12-coated polystyrene bead, hog intrinsic factor (HIF) and an alkaline phosphatase-labeled antibody specific for HIF. During a 30-minute incubation, the vitamin B12 released from endogenous binding proteins during sample treatment competes with immobilized vitamin B12 for binding with HIF. Alkaline phosphatase-labeled anti-HIF antibody binds to HIF and is immobilized only if HIF is bound to the B12-coated bead. Unbound enzyme conjugate is removed by centrifugal wash. Substrate is added. The chemiluminescent substrate, a phosphate ester of adamantyl dioxetane, undergoes hydrolysis in the presence of alkaline phosphatase to yield an unstable intermediate. The continuous production of this intermediate results in the sustained emission of light, thus improving precision by providing a window for multiple readings. The bound comblex - and thus also the photon output, as measured by the luminometer - is inversely proportional to the concentration of vitamin B12 in the sample.
Here's an analysis of the provided text, outlining the acceptance criteria and study details for the IMMULITE® 2000 Vitamin B12 device:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Performance Equivalence - Method Comparison (Correlation with predicate device) | The IMMULITE® 2000 Vitamin B12 procedure was compared to DPC's IMMULITE® Vitamin B12 (predicate device). Linear regression yielded: (IMMULITE® 2000) = 0.95 (IMMULITE®) - 34 pg/mL. The correlation coefficient (r) was 0.937. |
| Mean values (Comparison of means with predicate device) | IMMULITE® 2000 Mean: 400 pg/mL. IMMULITE® Mean (Predicate): 457 pg/mL. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 166 patient serum samples for the method comparison study.
- Data Provenance: The document does not specify the country of origin. It does not explicitly state if the data was retrospective or prospective, but the phrasing "patient serum samples" suggests existing samples were used, which would typically be retrospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This section is not applicable to this type of device. The ground truth for this device is established by a quantitative measurement using a legally marketed predicate device (DPC's IMMULITE® Vitamin B12), not by expert consensus or interpretation of images/data. The predicate device itself acts as the reference standard.
4. Adjudication Method for the Test Set
This section is not applicable. Since the comparison is against an established quantitative assay, there is no need for an adjudication method by experts to resolve disagreements, as would be the case in subjective diagnostic evaluation.
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
This section is not applicable. The device is an in-vitro diagnostic (IVD) assay for quantitative measurement of a biomarker (Vitamin B12), not an AI-assisted diagnostic imaging or interpretation tool that would involve human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, this was a standalone performance evaluation. The IMMULITE® 2000 Vitamin B12 device's performance was compared directly to the predicate IMMULITE® Vitamin B12 device without human intervention influencing the measurement results of either system. The method comparison described is a "standalone" evaluation of the new device's quantitative output against the established device's quantitative output.
7. The Type of Ground Truth Used
The ground truth for the comparison was the quantitative measurement of vitamin B12 in serum samples obtained using the IMMULITE® Vitamin B12 (the predicate device).
8. The Sample Size for the Training Set
The document does not explicitly mention a separate "training set". For this type of IVD, method comparison studies do not typically involve a training/test set split in the same way machine learning models do. The 166 patient samples were used for the performance comparison. If any internal validation or calibration was performed during development, that information is not provided here.
9. How the Ground Truth for the Training Set Was Established
Since a training set is not explicitly mentioned as a distinct component of the regulatory submission (as would be for an AI/ML device), the method for establishing its ground truth is also not described. For an IVD, the development and calibration typically rely on reference materials, calibrators, and internal validation studies, rather than a "ground truth" derived from human experts for a training set. The performance is then validated against a predicate device.
§ 862.1810 Vitamin B
12 test system.(a)
Identification. A vitamin B12 test system is a device intended to measure vitamin B12 in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of anemias of gastrointestinal malabsorption.(b)
Classification. Class II.