(26 days)
The DiaSorin LIAISON® VZV IgG uses chemiluminescence immunoassay (CLIA) technology on the LIAISON® Analyzer family for the qualitative detection of specific IgG antibodies to varicella-zoster virus (VZV) in human serum. This assay can be used as an aid in the determination of previous infection of varicella-zoster virus. The assay performance in detecting antibodies to VZV in individuals vaccinated with the FDA-licensed VZV vaccine is unknown. The user of this assay is responsible for establishing the performance characteristics with VZV vaccinated individuals.
The DiaSorin LIAISON® Control VZV IgG (negative and positive) is intended for use as assayed quality control samples to monitor the performance of the DiaSorin LIAISON® VZV IgG assay on the LIAISON® Analyzer family. The performance characteristics of the LIAISON® Control VZV IgG have not been established for any other assay or instrument platforms different from LIAISON® and LIAISON® XL.
The LIAISON® VZV IgG is an indirect chemiluminescence immunoassay (CLIA) for qualitative determination of specific IgG antibodies to varicella-zoster virus in human serum.
The LIAISON® Control VZV IqG are liquid ready-to-use controls based in human serum. The negative control is intended to provide an assay response characteristic of negative patient specimens and the positive control is intended to provide an assay response characteristic of positive patient specimens.
The assay and controls are designed for use with DiaSorin LIAISON® Analyzer familv.
This document describes modifications to the LIAISON® VZV IgG assay and LIAISON® Control VZV IgG, and provides a summary of performance data to support the substantial equivalence to the predicate device.
Here's the breakdown of the requested information based on the provided text:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly present a table of acceptance criteria with reported numerical performance values against them. Instead, it states that "Non-clinical verification and validation testing conducted with the LIAISON® VZV IgG and LIAISON® Control VZV IgG demonstrate that the modified devices met predetermined acceptance criteria".
The types of claims supported by testing are listed:
| Acceptance Criteria (Implied by claims) | Reported Device Performance (Implied by meeting criteria) |
|---|---|
| LIAISON® VZV IgG: | |
| 8 weeks On-Board/Open Use Stability | Met predetermined acceptance criteria |
| 8 weeks Stability of Calibration | Met predetermined acceptance criteria |
| 7 Days Refrigerated (2-8°C) Serum Storage | Met predetermined acceptance criteria |
| 5 Freeze-Thaw Cycles Serum Storage | Met predetermined acceptance criteria (no significant differences reported) |
| LIAISON® Control VZV IgG: | |
| Commutability between Samples and Controls (Matrix Effect) | Met predetermined acceptance criteria |
| Precision Equivalence between Samples and Controls (20 Day & 5 Day Precision) | Met predetermined acceptance criteria |
| Control Value Assignment | Met predetermined acceptance criteria |
| Control Range Definition | Met predetermined acceptance criteria |
| 18 months Shelf-life (2-8°C) | Met predetermined acceptance criteria |
| 8 weeks On-Board/Open Use Stability | Met predetermined acceptance criteria |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- LIAISON® VZV IgG Serum Storage Freeze-Thaw Cycles: "Twelve samples with different reactivity underwent five (5) freeze-thaw cycles."
- Other tests: The exact sample sizes for other tests (stability, commutability, precision, control value assignment, control range definition) are not explicitly stated in this summary.
- Data Provenance: The document does not specify the country of origin of the data or whether the studies were retrospective or prospective. It only states "Non-clinical verification and validation testing conducted...".
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
This information is not provided in the document. The LIAISON® VZV IgG is a chemiluminescence immunoassay (CLIA) for detecting specific IgG antibodies to VZV in human serum. Its performance relies on the assay's chemical and biological properties, not on human interpretation by experts in the context of this specific regulatory submission for modifications. The "ground truth" for VZV IgG assays is typically established through reference methods or well-characterized clinical samples, not by expert readers.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
This information is not applicable and therefore not provided in the document. Adjudication methods are typically relevant for studies involving human interpretation or subjective assessments, such as imaging studies where multiple readers might interpret images. This device is an in-vitro diagnostic assay.
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 information is not applicable and therefore not provided in the document. The LIAISON® VZV IgG is an automated in-vitro diagnostic assay and does not involve human readers or AI assistance in its direct operation or interpretation for a comparative effectiveness study as described.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
The device itself (LIAISON® VZV IgG) is an automated standalone assay for qualitative detection of VZV IgG antibodies. The performance data presented (stability, precision, etc.) are inherent to the device's operational characteristics without human intervention influencing the assay's result generation. This aligns with the concept of "standalone performance" for an IVD device.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The document does not explicitly state the specific "ground truth" method used for the initial assays or for validating the modified claims. For an immunoassay like this, the ground truth would typically be established by:
- Reference methods: Comparison to a gold standard VZV IgG assay.
- Well-characterized clinical samples: Samples from individuals with confirmed VZV infection history or vaccination status, or known serological status.
The purpose of this submission is to demonstrate equivalence of modifications to a previously cleared device, not to re-establish the fundamental clinical validity against a primary ground truth.
8. The sample size for the training set
This information is not applicable and therefore not provided in the document. This is a traditional immunoassay, not a machine learning or AI-based device that would require a distinct "training set." The development of such assays involves reagent formulation, optimization, and extensive verification and validation studies.
9. How the ground truth for the training set was established
This information is not applicable and therefore not provided in the document, as there is no "training set" in the context of this traditional immunoassay.
§ 866.3900 Varicella-zoster virus serological reagents.
(a)
Identification. Varicella-zoster virus serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to varicella-zoster in serum. The identification aids in the diagnosis of diseases caused by varicella-zoster viruses and provides epidemiological information on these diseases. Varicella (chicken pox) is a mild, highly infectious disease, chiefly of children. Zoster (shingles) is the recurrent form of the disease, occurring in adults who were previously infected with varicella-zoster viruses. Zoster is the response (characterized by a rash) of the partially immune host to a reactivation of varicella viruses present in latent form in the patient's body.(b)
Classification. Class II (performance standards).