(24 days)
For in vitro use with the IMMULITE® 2000 Automated Analyzer - for the qualitative detection of IgG antibodies to cytomegalovirus (CMV) in human serum as an aid in the determination of serological status to CMV. This kit is not cleared for use in testing (i.e. screening) blood or plasma donors.
IMMULITE® 2000 CMV IgG is a clinical use device intended for use with the IMMULITE® 2000 Automated Immunoassay Analyzer. IMMULITE® 2000 CMV IgG is a chemiluminescent immunoassay. The sold phase, a polystyrene bead enclosed within an IMMULITE Test Unit/IMMULITE 2000 Reaction Tube is coated with partially purified CMV antigen. One-in-twenty one prediluted patient sample for IMMULITE/instrument-diluted patient sample for IMMULITE 2000 and a protein-based buffer are simultaneously introduced into the Test Unit (IMMULITE)/Reaction Tube (IMMULITE 2000), and incubated for approximately 30 minutes at 37℃ with intermittent agitation. During this time, CMV-specific IgG in the sample binds to the CMV antigen-coated bead. Unbound serum is then removed by a centrifugal wash. In both procedures, an alkaline phosphatase-labeled anti-human IgG antibody is introduced, and the Test Unit/Reaction Tube is incubated for another 30-minute cycle. The unbound enzyme conjugate is removed by a centrifugal wash. Substrate is then added, and the Test Unit/Reaction Tube is incubated for a further 10 minutes (IMMULITE)/5 minutes (IMMULITE 2000). In both procedures, 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 complex - and thus also the photon output, as measured by the luminometer - is related to the presence of CMV IgG in the sample. A qualitative result is then obtained by comparing the patient result to an established cutoff.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" as a separate, pre-defined set of targets. Instead, it presents a "Performance Equivalence - Method Comparison" study with the implicit understanding that high agreement, relative sensitivity, and relative specificity with the predicate device are the metrics for demonstrating equivalence.
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance (IMMULITE® 2000 CMV IgG vs. IMMULITE® CMV IgG) |
|---|---|---|
| Agreement | High agreement (e.g., >95%) | 99.6% |
| Relative Sensitivity | High sensitivity (e.g., >95%) | 100% |
| Relative Specificity | High specificity (e.g., >95%) | 100% |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 229 samples.
- Data Provenance: The document does not specify the country of origin for the samples or whether they were retrospective or prospective.
3. Number of Experts Used to Establish Ground Truth and Qualifications
The document does not mention the use of experts to establish ground truth for this comparison study. The comparison is between two devices, implying that the ground truth for this study is essentially the performance of the predicate device (IMMULITE® CMV IgG).
4. Adjudication Method for the Test Set
No adjudication method is described. The comparison is a direct method comparison between two assays.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done
An MRMC study was not conducted. This is a comparison between two automated immunoassay devices, not a study involving human readers with and without AI assistance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, this study is a standalone performance assessment of the new IMMULITE® 2000 CMV IgG device against a predicate device (IMMULITE® CMV IgG). Both are automated immunoassay systems, operating without human interpretation in the results generation process depicted here.
7. The Type of Ground Truth Used
The "ground truth" for this performance equivalence study is the performance of the predicate device, IMMULITE® CMV IgG. The study aims to demonstrate that the new device performs equivalently to an already cleared device.
8. The Sample Size for the Training Set
The document does not provide information about a separate training set for the IMMULITE® 2000 CMV IgG device. This submission is for a new iteration of an immunoassay, and the focus is on demonstrating equivalence to a previous version rather than presenting a de novo algorithm training process.
9. How the Ground Truth for the Training Set was Established
As no training set is described, there's no information on how its ground truth would have been established. It's likely that the original IMMULITE® CMV IgG (the predicate device) would have undergone its own validation studies where ground truth for determining CMV IgG status was established through methods like clinical diagnosis, seroconversion panels, or other established laboratory methods for infectious disease diagnosis.
§ 866.3175 Cytomegalovirus serological reagents.
(a)
Identification. Cytomegalovirus serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to cytomegalovirus in serum. The identification aids in the diagnosis of diseases caused by cytomegaloviruses (principally cytomegalic inclusion disease) and provides epidemiological information on these diseases. Cytomegalic inclusion disease is a generalized infection of infants and is caused by intrauterine or early postnatal infection with the virus. The disease may cause severe congenital abnormalities, such as microcephaly (abnormal smallness of the head), motor disability, and mental retardation. Cytomegalovirus infection has also been associated with acquired hemolytic anemia, acute and chronic hepatitis, and an infectious mononucleosis-like syndrome.(b)
Classification. Class II (performance standards).