VARICELLA-ZOSTER VIRUS DIRECT IMMUNOFLUORESCENCE ASSAY

• K Number: K951799
• Device Name: VARICELLA-ZOSTER VIRUS DIRECT IMMUNOFLUORESCENCE ASSAY
• Manufacturer: LIGHT DIAGNOSTICS
• Date Cleared: 1996-03-20 ( 336 days)
• Product Code: GQX
• Regulation Number: 866.3900

Intended Use

Light Diagnostics Varicella-zoster virus Direct Immunofluorescence Assay is intended for in vitro diagnostic use in the qualitative detection of VZV from vesicular smears and in cell culture viral isolation and confirmation.

Device Description

Light Diagnostics Varicella-zoster virus direct Immunofluorescence DFA) uses the standard laboratory direct Assav (VZV immunofluorescence technique for the culture confirmation and direct specimen detection of Varicella-zoster virus. The DFA is based on the principle of antigen identification using a detector monoclonal antibody conjugated to fluorescein isothiocyanate. The substrate consists of a slide prepared from a direct specimen vesicular smear or the tissue cultured cells from a clinical specimen inoculum. Anti VZV FITC labeled antibody is applied to the substrate. The antibody will bind to specific antigen, if present, in the substrate. The fluorescein conjugated monoclonal antibody allows for visualization of the antigen / antibody complex by fluorescence microscopy. A blend of mouse monoclonal antibodies are used as detector antibodies in Light Diagnostics Varicella-zoster virus direct Immunofluorescence Assay. The monoclonal antibodies are specific for the glycoprotein gp I or the immediate early antigen of VZV. The use of monoclonal antibodies ensures increased specificity and reduced non-specific interference.

Predicate Devices

Not Found

Reference Devices

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AI/ML (Artificial Intelligence / Machine Learning)

No
The device description details a standard immunofluorescence assay technique and does not mention any AI or ML components. The performance studies are based on traditional clinical evaluation metrics.

Therapeutic

No

The device is an in vitro diagnostic assay for detecting VZV, not for treating a disease.

Diagnostic

Yes
The "Intended Use / Indications for Use" section explicitly states that the device "is intended for in vitro diagnostic use in the qualitative detection of VZV".

SaMD (Software as a Medical Device)

No

The device description clearly outlines a laboratory assay using antibodies, fluorescence microscopy, and physical specimens (vesicular smears, cell cultures). This involves physical reagents and hardware (microscope), not just software.

IVD (In Vitro Diagnostic)

Yes, this device is an IVD (In Vitro Diagnostic).

Here's why:

• Intended Use: The "Intended Use / Indications for Use" section explicitly states "is intended for in vitro diagnostic use".
• Device Description: The description details a laboratory test performed on biological samples (vesicular smears and cell culture) to detect a specific virus (VZV). This is a hallmark of an in vitro diagnostic test.
• Performance Studies: The document describes a clinical evaluation comparing the device to another diagnostic kit, providing performance metrics like sensitivity and specificity, which are relevant to diagnostic accuracy.
• Predicate Device: The mention of a "Predicate Device" (Meridian Diagnostics, Inc. Merifluor VZV) further indicates that this device is being compared to another legally marketed IVD.

All of these points strongly support the classification of this device as an In Vitro Diagnostic.

PCCP (Predetermined Change Control Plan) Authorized

N/A

Overview

Intended Use / Indications for Use

Light Diagnostics Varicella-zoster virus Direct Immunofluorescence Assay is intended for in vitro diagnostic use in the qualitative detection of VZV from vesicular smears and in cell culture viral isolation and confirmation.

Product codes

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Device Description

Light Diagnostics Varicella-zoster virus direct Immunofluorescence DFA) uses the standard laboratory direct Assav (VZV immunofluorescence technique for the culture confirmation and direct specimen detection of Varicella-zoster virus. The DFA is based on the principle of antigen identification using a detector monoclonal antibody conjugated to fluorescein isothiocyanate. The substrate consists of a slide prepared from a direct specimen vesicular smear or the tissue cultured cells from a clinical specimen inoculum. Anti VZV FITC labeled antibody is applied to the substrate. The antibody will bind to specific antigen, if present, in the substrate. The fluorescein conjugated monoclonal antibody allows for visualization of the antigen / antibody complex by fluorescence microscopy.

A blend of mouse monoclonal antibodies are used as detector antibodies in Light Diagnostics Varicella-zoster virus direct Immunofluorescence Assay. The monoclonal antibodies are specific for the glycoprotein gp I or the immediate early antigen of VZV. The use of monoclonal antibodies ensures increased specificity and reduced non-specific interference.

Mentions image processing

Not Found

Mentions AI, DNN, or ML

Not Found

Input Imaging Modality

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Anatomical Site

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Indicated Patient Age Range

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Intended User / Care Setting

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Description of the training set, sample size, data source, and annotation protocol

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Description of the test set, sample size, data source, and annotation protocol

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Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)

Nonclinical evaluation: The conjugated monoclonal antibodies used in the kit were characterized for their ability to detect Varicella-zoster virus. The anti VZV antibodies reacted concordantly when tested with reference virus strains and clinical isolates. The conjugated monoclonal antibodies were evaluated for cross reactivity to a variety of viral pathogens and host cell controls. No discordant results were obtained.

Clinical Evaluation: Light Diagnostics Varicella-zoster virus Direct Immunofluorescence Assay was compared in clinical evaluation to the Meridian Diagnostics, Inc. Merifluor kit for direct specimen detection and cell culture isolation / confirmation. Two hundred and five specimens were evaluated with results for 95% confidence interval sensitivity of 91.3% to 100% and specificity of 96.2% to 100%.

Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)

95% confidence interval sensitivity of 91.3% to 100% and specificity of 96.2% to 100%.

Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.

Not Found

Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.

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Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc).

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Regulation Number and Section

§ 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).

Summary

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K951799

510(k) SUMMARY

MAR 20 1996

• 1. 510(k) Light Diagnostics 28835 Single Oak Drive Temecula, California 92590
     Contact Person: Dale Dembrow [phone] Extension 230
• 2. Device: Light Diagnostics Varicella-zoster Virus Direct Immunofluorescence Assay A direct immunofluorescence assay for the identification of Varicella-zoster virus

• Substantial Equivalence to:

Meridian Diagnostics, Inc. Merifluor VZV

Varicella-zoster virus direct fluorescence antibody stain for VZV identification.

:

• 4. Device Description:
     Light Diagnostics Varicella-zoster virus direct Immunofluorescence DFA) uses the standard laboratory direct Assav (VZV immunofluorescence technique for the culture confirmation and direct specimen detection of Varicella-zoster virus. The DFA is based on the principle of antigen identification using a detector monoclonal antibody conjugated to fluorescein isothiocyanate. The substrate consists of a slide prepared from a direct specimen vesicular smear or the tissue cultured cells from a clinical specimen inoculum. Anti VZV FITC labeled antibody is applied to the substrate. The antibody will bind to specific antigen, if present, in the substrate. The fluorescein conjugated monoclonal antibody allows for visualization of the antigen / antibody complex by fluorescence microscopy.

A blend of mouse monoclonal antibodies are used as detector antibodies in Light Diagnostics Varicella-zoster virus direct Immunofluorescence Assay. The monoclonal antibodies are specific for the glycoprotein gp I or the immediate early antigen of VZV. The use of monoclonal antibodies ensures increased specificity and reduced non-specific interference.

1

510(k) SUMMARY

5. Intended Use:

Light Diagnostics Varicella-zoster virus Direct Immunofluorescence Assay is intended for in vitro diagnostic use in the qualitative detection of VZV from vesicular smears and in cell culture viral isolation and confirmation.

• 6. Technological Characteristics Comparison of Light Diagnostics Varicella-zoster virus Direct Immunofluorescence Assay and the Merifluor VZV kit:
  • Both kits use standard immunofluorescence assay a. Principle: technique using substrate slides prepared from vesicular smears or technique using substrate slides prep the cells from tissue culture isolation
  • Materials: Both kits incorporate monoclonal antibodies specific for b. VZV as the detector antibodies.

Performance Data for Light Diagnostics Varicella-zoster virus Direct Immunofluorescence Assay Kit

• 1. Nonclinical evaluation:
     The conjugated monoclonal antibodies used in the kit were characterized for their ability to detect Varicella-zoster virus. The anti VZV antibodies reacted concordantly when tested with reference virus strains and clinical isolates.

The conjugated monoclonal antibodies were evaluated for cross reactivity to a variety of viral pathogens and host cell controls. No discordant results were obtained.

• 2. Clinical Evaluation:
     Light Diagnostics Varicella-zoster virus Direct Immunofluorescence Assay was compared in clinical evaluation to the Meridian Diagnostics, Inc. Merifluor kit for direct specimen detection and cell culture isolation / confirmation.

Two hundred and five specimens were evaluated with results for 95% confidence interval sensitivity of 91.3% to 100% and specificity of 96.2% to 100%.

2

510(k) SUMMARY

Conclusions Drawn from Evaluations: 3.

Light Diagnostics Varicella-zoster virus Direct Immunofluorescence Assay Kit uses the standard laboratory DFA in the culture confirmation and direct detection of Varicella-zoster virus. The monoclonal antibodies used in the kit have been characterized to ensure maximum specificity and reliability. In clinical evaluations, the kit performed consistent with results obtained using the Meridian Diagnostics, Inc. Merifluor VZV in vitro diagnostic kit.

The characterization and clinical evaluation of Light Diagnostics Varicella-zoster Direct Immunofluorescence Assay verifies its safety and effectiveness when used as intended. . .