(243 days)
The LIAISON® VZV IgG Assay uses chemiluminescence immunoassay (CLIA) technology on the LIAISON® Analyzer for the qualitative detection of specific IgG antibodies to varicella-zoster virus in human serum. This assay can be used as an aid in the determination of previous infection of varicella-zoster virus.
The method for the qualitative determination of specific IgG to varicella- zoster virus is an indirect chemiluminescence immunoassay (CLIA). All assay steps and incubations are performed by the LIAISON® Analyzer.
Varicella-zoster virus antigen is used for coating magnetic particles (solid phase) and a mouse monoclonal antibody to human IgG is linked to an isoluminol derivative (isoluminol-antibody conjugate). During the first incubation, anti-VZV IgG antibodies, present in calibrators, samples or controls, bind to the solid phase. After each incubation, the unbound material is removed with a wash cycle. During the second incubation, the antibody conjugate reacts with anti-VZV IgG already bound to the solid phase. Subsequently, the starter reagents are added and a flash chemiluminescence reaction is induced. The light signal, directly related to the amount of isoluminol-antibody conjugate, is measured by a photomultiplier as relative light units (RLU) and is indicative of the presence of anti-VZV IgG in calibrators, samples or controls.
Here's a breakdown of the acceptance criteria and study information for the DiaSorin LIAISON® VZV IgG device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are implied by the clinical trial results. The device aims to demonstrate substantial equivalence to the predicate device.
| Metric | Acceptance Criteria (Implied) | Reported Device Performance (General Samples) | Reported Device Performance (Pregnant Women) |
|---|---|---|---|
| Positive Agreement | High agreement with predicate device for positive samples | 98.8% (97.7 - 99.5% 95% CI) | 99.2% (98.2 - 99.7% 95% CI) |
| Negative Agreement | High agreement with predicate device for negative samples | 84.4% (74.4 - 91.7% 95% CI) | 64.1% (47.6 - 78.8% 95% CI) |
| Overall Reproducibility | Consistent results across runs, sites, and operators (low %CV) | See detailed tables below | See detailed tables below |
| Assay Precision | Consistent results over time on a single instrument (low %CV) | See detailed tables below | See detailed tables below |
Reproducibility (3-site, 5-day study with 3 kit lots):
| ID# | N | Mean Index (Overall %CV) |
|---|---|---|
| DiaSorin Neg Ctl | 60 | 30.3 (18.6) |
| DiaSorin Pos Ctl | 60 | 434 (14.4) |
| 011006 (Cutoff Ctl) | 60 | 246 (13.8) |
| BR Neg Ctl (100% serum) | 60 |
§ 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).