INCSTAR TOXOPLASMA IGM CAPTURE ELISA ASSAY

K963289 · Incstar Corp. · LGD · May 1, 1997 · Microbiology

Device Facts

• Record ID: K963289
• Device Name: INCSTAR TOXOPLASMA IGM CAPTURE ELISA ASSAY
• Applicant: Incstar Corp.
• Product Code: LGD · Microbiology
• Decision Date: May 1, 1997
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3780
• Device Class: Class 2

Intended Use

The INCSTAR Toxoplasma IgM Capture ELISA kit contains instructions and materials for the qualitative detection of IgM antibodies to Toxoplasma gondii in human serum by reverse capture enzyme-linked immunosorbent assay (ELISA) technique. When performed according to instructions, the Toxoplasma IgM Capture ELISA test can be used as an aid in the diagnosis of current or recent active Toxoplasma gondii infection. This product is not FDA cleared for use in testing (i.e., screening) blood or plasma donors.

Device Story

In vitro diagnostic ELISA kit; detects IgM antibodies to Toxoplasma gondii in human serum. Principle: reverse capture ELISA; monoclonal mouse anti-human IgM bound to microtiter wells captures patient IgM; Toxoplasma antigen conjugated to horseradish peroxidase (HRP) binds captured anti-Toxoplasma IgM; chromogen added for colorimetric detection. Absorbance measured at 450/630 nm; signal proportional to IgM concentration. Used in clinical laboratories by trained personnel. Results aid clinicians in diagnosing active Toxoplasma infection. Not for blood/plasma donor screening.

Clinical Evidence

Clinical performance study compared INCSTAR kit to BioWhittaker TOXOCAP-M ELISA using 406 serum samples from 375 individuals (healthy, transplant, immunocompromised, pregnant, and infected patients). Results showed relative sensitivity 91-99%, relative specificity 99-100%, and overall agreement 97-100% (95% CI). Additional studies included correlation, prevalence, cross-reactivity, interference, IgM specificity, and precision.

Technological Characteristics

Reverse capture ELISA; monoclonal mouse anti-human IgM (μ chain specific) coated microtiter wells; Toxoplasma antigen-HRP conjugate; chromogenic substrate. Photometric detection at 450/630 nm. In vitro diagnostic reagent kit.

Indications for Use

Indicated for qualitative detection of IgM antibodies to Toxoplasma gondii in human serum to aid in diagnosis of current or recent active infection. Population includes healthy donors, transplant patients, immunocompromised hosts, and pregnant women.

Regulatory Classification

Identification

Toxoplasma gondii serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to Toxoplasma gondii in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to identify Toxoplasma gondii from clinical specimens. The identification aids in the diagnosis of toxoplasmosis caused by the parasitic protozoan Toxoplasma gondii and provides epidemiological information on this disease. Congenital toxoplasmosis is characterized by lesions of the central nervous system, which if undetected and untreated may lead to brain defects, blindness, and death of an unborn fetus. The disease is characterized in children by inflammation of the brain and spinal cord.

Predicate Devices

• BioWhittaker TOXOCAP-M ELISA

Submission Summary (Full Text)

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1<963289

MAY - 1 1997

# I. SUMMARY OF SAFETY AND EFFECTIVENESS

**DEVICE NAME:** INCSTAR Toxoplasma IgM Capture ELISA Kit

**CLASSIFICATION:** Toxoplasma gondii Serological Reagents
21 CFR 866.3780
Class II (Performance Standards)

**APPLICANT:** INCSTAR Corporation
1990 Industrial Boulevard
Stillwater, Minnesota 55082-0285

**INTENDED USE:**

The INCSTAR Toxoplasma IgM Capture ELISA kit contains instructions and materials for the qualitative detection of IgM antibodies to *Toxoplasma gondii* in human serum by reverse capture enzyme-linked immunosorbent assay (ELISA) technique. When performed according to instructions, the Toxoplasma IgM Capture ELISA test can be used as an aid in the diagnosis of current or recent active *Toxoplasma gondii* infection. This product is not FDA cleared for use in testing (i.e., screening) blood or plasma donors.

**DEVICE DESCRIPTION:**

The INCSTAR Toxoplasma IgM Capture ELISA Kit utilizes the enzyme-linked immunosorbent assay (ELISA) based on the antibody capture technique. Diluted patient serum is incubated with monoclonal mouse antibody against human IgM (μ chain specific) bound to the solid surface of the microtiter well. Patient IgM is “captured” by the surface bound antibody. The presence of patient anti-*Toxoplasma* IgM antibodies are then “detected” and bound by *Toxoplasma* antigen which is linked to an anti-*Toxoplasma* antibody conjugated to horseradish peroxidase. Bound horseradish peroxidase is reacted with chromogen, resulting in color development. The absorbance of the solution, measured at 450 nm / 630 nm, is directly proportional to the concentration of IgM to *Toxoplasma* antigen present in the reaction solution.

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# I. SUMMARY OF SAFETY AND EFFECTIVENESS (continued)

## SAFETY AND EFFECTIVENESS:

The INCSTAR Toxoplasma IgM Capture ELISA Kit is substantially equivalent (SE) to the BioWhittaker TOXOCAP-M ELISA test which has been cleared by the FDA and is currently in U.S. commercial distribution.

In clinical performance studies, 406 serum samples represented by 375 individuals were tested with the INCSTAR Toxoplasma IgM Capture ELISA kit and results were compared to those results generated from the BioWhittaker TOXOCAP-M ELISA kit. The samples utilized represent a mixed population of healthy donors, transplant patients, immunocompromised hosts, pregnant women, *Toxoplasma* proven individuals, and patients having various other illnesses. Upon completion of assay correlation, the results (using 95% confidence intervals) demonstrated relative sensitivity of 91% to 99% and relative specificity of 99% to 100%. In addition, the assay displayed an overall agreement of 97% to 100%.

Correlation, prevalence, cross-reactivity, interference, IgM specificity and precision studies have been conducted and are summarized in the INCSTAR Toxoplasma IgM Capture Kit package insert.