INCSTAR TOXOPLASMA IGG ALISA ASSAY (CAT.#7565)

K963296 · Incstar Corp. · LGD · Dec 16, 1996 · Microbiology

Device Facts

• Record ID: K963296
• Device Name: INCSTAR TOXOPLASMA IGG ALISA ASSAY (CAT.#7565)
• Applicant: Incstar Corp.
• Product Code: LGD · Microbiology
• Decision Date: Dec 16, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3780
• Device Class: Class 2
• Attributes: Pediatric

Intended Use

The INCSTAR Toxoplasma IgG ELISA kit contains instructions and materials for qualitative and/or semi-quantitative detection of IgG antibodies to Toxoplasma gondii in human serum by indirect enzyme-linked immunosorbent assay (ELISA) technique. When performed according to instructions, the Toxoplasma IgG ELISA is of value in the determination of immunological response to infection with Toxoplasma gondii. The evaluation of paired sera, acute and convalescent, by demonstrating seroconversion or a significant rise in antibody can aid in the diagnosis of primary or reactivated infection with Toxoplasma gondii. 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 IgG antibodies to Toxoplasma gondii in human serum. Principle: Polystyrene microtiter wells coated with purified T. gondii antigen; patient serum incubated; captured IgG detected via goat anti-human IgG (Fc) conjugated to horseradish peroxidase; chromogen (tetramethylbenzidine) added; color reaction measured via photometer at 450/630 nm. Enzyme activity proportional to anti-Toxoplasma IgG concentration. Used in clinical laboratories; results interpreted by healthcare providers to assess immunological response and aid diagnosis of primary or reactivated toxoplasmosis.

Clinical Evidence

Clinical study of 300 serum samples from 269 individuals (infants, transplant patients, immunocompromised, pregnant women). Compared INCSTAR kit to Gull Toxoplasma IgG ELISA. Results: relative sensitivity 98-100%, relative specificity 92-99%, overall agreement 96-99% (95% CI).

Technological Characteristics

Indirect ELISA; polystyrene microtiter wells coated with purified Toxoplasma gondii antigen; goat anti-human IgG (Fc) horseradish peroxidase conjugate; tetramethylbenzidine chromogen; photometric detection at 450/630 nm.

Indications for Use

Indicated for qualitative/semi-quantitative detection of IgG antibodies to Toxoplasma gondii in human serum to aid in diagnosis of primary or reactivated infection. Population includes infants, transplant patients, immunocompromised hosts, and pregnant women. Not for blood/plasma donor screening.

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

• Gull Toxoplasma IgG ELISA test (K915891)

Submission Summary (Full Text)

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DEC 16 1996
K963296

# I. SUMMARY OF SAFETY AND EFFECTIVENESS

**DEVICE NAME:** INCSTAR Toxoplasma IgG 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 IgG ELISA kit contains instructions and materials for qualitative and/or semi-quantitative detection of IgG antibodies to *Toxoplasma gondii* in human serum by indirect enzyme-linked immunosorbent assay (ELISA) technique. When performed according to instructions, the Toxoplasma IgG ELISA is of value in the determination of immunological response to infection with *Toxoplasma gondii*. The evaluation of paired sera, acute and convalescent, by demonstrating seroconversion or a significant rise in antibody can aid in the diagnosis of primary or reactivated infection with *Toxoplasma gondii*. This product is not FDA cleared for use in testing (i.e., screening) blood or plasma donors.

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# I. SUMMARY OF SAFETY AND EFFECTIVENESS (continued)

## DEVICE DESCRIPTION:

The method for the determination of specific anti-Toxoplasma IgG utilizes the enzyme-linked immunosorbent assay (ELISA) technique. Polystyrene microtiter wells are coated with purified Toxoplasma gondii antigen. Diluted patient serum is incubated with the purified antigen bound to the solid surface of a microtiter well. The Toxoplasma IgG antibodies present in a patient's serum will be captured by the solid phase. After washing, affinity purified polyclonal goat anti-human IgG (Fc) antibodies conjugated to horseradish peroxidase are added to the well. After this incubation, chromogen containing tetramethylbenzidine is added. Enzyme action on the chromogen results in a color reaction. The color can be detected with a photometer at a dual wavelength of 450 nm / 630 nm. The measured enzyme activity is directly proportional to the concentration of specific anti-Toxoplasma IgG bound to the solid phase.

## SAFETY AND EFFECTIVENESS:

The INCSTAR Toxoplasma IgG ELISA Kit is substantially equivalent (SE) to the Gull Toxoplasma IgG ELISA test, 510(k) No. K915891, which has been cleared by the FDA and is currently in U.S. commercial distribution.

In clinical performance studies, 300 serum samples represented by 269 individuals were tested with the INCSTAR Toxoplasma IgG Kit and results were compared to those results generated from the Gull Toxoplasma IgG ELISA kit. The samples utilized represent a mixed population of infants, transplant patients, immunocompromised hosts, pregnant women being screened for toxoplasmosis, and patients having various other illnesses. Upon completion of assay correlation, the results (using 95% confidence intervals) demonstrated relative sensitivity of 98% to 100% and relative specificity of 92% to 99%. In addition, the assay displayed an overall agreement of 96% to 99%.

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# I. SUMMARY OF SAFETY AND EFFECTIVENESS (continued)

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