(71 days)
For in vitro diagnostic use only.
The VITROS Immunodiagnostic Products Rubella IgG assay is intended for the quantitative determination of IgG antibodies to rubella virus in human serum and plasma (heparin, EDTA or sodium citrate) using the VITROS Immunodiagnostic System.
The VITROS Rubella IgG assay is for use in the clinical laboratory to aid in the determination of immunity to rubella virus infection.
The VITROS Rubella IgG assay is performed using the VITROS Immunodiagnostic Products Rubella IgG Reagent Pack and VITROS Immunodiagnostic Products Rubella IgG Calibrators on the VITROS Immunodiagnostic System for the qualitative and quantitative determination of rubella IgG antibodies to rubella virus in human serum and plasma. An immunometric technique is used. This involves the reaction of antirubella IgG present in the sample with rubella antigen coated onto the wells. After a wash step a horseradish peroxidase (HRP)-labeled antibody conjugate (mouse monoclonal anti-human IgG) is added and this complexes with bound anti-rubella IgG. Unbound materials are removed by washing. The bound HRP conjugate is measured by a luminescent reaction. A reagent containing luminogenic substrates (a luminol derivative and a peracid salt) and an electron transfer agent, is added to the wells. The HRP in the bound conjugate catalyzes the oxidation of the luminol derivative, producing light. The electron transfer agent (a substituted acetanilide) increases the level of light produced and prolongs its emission. The light signals are read by the VITROS Immunodiagnostic System. The amount of HRP conjugate bound is directly proportional to the concentration of antirubella IgG present.
Here's a breakdown of the acceptance criteria and study information for the VITROS Rubella IgG Assay, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state formal "acceptance criteria" in a numerical target format (e.g., "Sensitivity must be >95%"). Instead, it compares the performance of the new device to a predicate device. The "acceptance" is implied by demonstrating substantial equivalence to the predicate device.
| Performance Metric | Predicate Device (ABBOTT AxSYM Rubella IgG Assay) | New Device (VITROS Rubella IgG Assay) - Study 1 | New Device (VITROS Rubella IgG Assay) - Study 2 |
|---|---|---|---|
| Positive % Agreement / Initial Sensitivity | 99.5% | 98.6% | 97.5% |
| Negative % Agreement / Initial Specificity | 90.8% | 91.1% | 98.3% |
| Linearity with W.H.O. 1st International standard - Assay range | r = 0.9999 | r = 0.999 | Not applicable (single study for this metric) |
| Linearity with W.H.O. 1st International standard from 0-20 IU/mL | Unknown | r = 0.9988 | Not applicable (single study for this metric) |
| CDC Panel evaluation | Yes | Yes | Not applicable (single study for this metric) |
2. Sample Size Used for the Test Set and Data Provenance
The document does not specify the exact sample size for the test sets (i.e., the number of samples used to determine Positive % Agreement and Negative % Agreement). It also does not explicitly state the country of origin of the data or whether the studies were retrospective or prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not provide information about the number of experts, their qualifications, or how they established the ground truth for the test set.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method used for the test set.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study is an in-vitro diagnostic device (IVD) for laboratory use and does not involve human readers interpreting results. Inter-rater variability studies are more applicable to imaging or subjective interpretations rather than quantitative immunoassay results.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, this is implicitly a standalone performance study. The "device performance" refers to the output of the VITROS Immunodiagnostic System itself, without a human in the loop for interpretation beyond running the assay and reading the quantitative results. The output of the device is a quantitative determination of IgG antibodies, which is then used by laboratory personnel to aid in determining immunity.
7. The Type of Ground Truth Used
The document does not explicitly state the specific type of "ground truth" used for the studies that generated the Positive % Agreement and Negative % Agreement. However, given that it's an immunoassay for rubella IgG, the ground truth would typically be established by:
- Reference Methods: Highly sensitive and specific laboratory reference assays for rubella IgG antibodies.
- Clinical Status: Correlation with confirmed rubella infection history or vaccination status for clinical immunity determination.
- CDC Panel Evaluation: The mention of "CDC Panel evaluation" indicates that standardized panels from the Centers for Disease Control and Prevention were likely used, which represent well-characterized samples with established rubella IgG status.
8. The Sample Size for the Training Set
The document does not provide information about the sample size used for a training set. This is typical for in-vitro diagnostic assays, where a "training set" in the context of machine learning isn't usually a separate, explicitly defined component in the same way it would be for a typical AI/ML medical device. Instead, the assay's design, calibration, and optimization (which can be considered analogous to "training") are performed using a range of characterized samples during the development phase.
9. How the Ground Truth for the Training Set Was Established
Since an explicit "training set" as understood in AI/ML is not described, the method for establishing its "ground truth" is also not detailed. However, for the development and optimization of such an immunoassay, the manufacturer would use precisely characterized samples with known concentrations or presence/absence of rubella IgG antibodies, likely derived from reference materials, clinical samples with confirmed status, and potentially fortified samples.
§ 866.3510 Rubella virus serological reagents.
(a)
Identification. Rubella virus serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to rubella virus in serum. The identification aids in the diagnosis of rubella (German measles) or confirmation of a person's immune status from past infections or immunizations and provides epidemiological information on German measles. Newborns infected in the uterus with rubella virus may be born with multiple congenital defects (rubella syndrome).(b)
Classification. Class II. The special controls for this device are:(1) National Committee for Clinical Laboratory Standards':
(i) 1/LA6 “Detection and Quantitation of Rubella IgG Antibody: Evaluation and Performance Criteria for Multiple Component Test Products, Speciment Handling, and Use of the Test Products in the Clinical Laboratory, October 1997,”
(ii) 1/LA18 “Specifications for Immunological Testing for Infectious Diseases, December 1994,”
(iii) D13 “Agglutination Characteristics, Methodology, Limitations, and Clinical Validation, October 1993,”
(iv) EP5 “Evaluation of Precision Performance of Clinical Chemistry Devices, February 1999,” and
(v) EP10 “Preliminary Evaluation of the Linearity of Quantitive Clinical Laboratory Methods, May 1998,”
(2) Centers for Disease Control's:
(i) Low Titer Rubella Standard,
(ii) Reference Panel of Well Characterized Rubella Sera, and
(3) World Health Organization's International Rubella Standard.