INCSTAR TOXOPLASMA IGG FAST ELISA ASSAY (CAT.#7560)

K963297 · Incstar Corp. · LGD · Dec 16, 1996 · Microbiology

Device Facts

• Record ID: K963297
• Device Name: INCSTAR TOXOPLASMA IGG FAST ELISA ASSAY (CAT.#7560)
• 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 “fast” ELISA kit contains instructions and materials for the 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 “fast” ELISA test is of value in the determination 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

Indirect ELISA assay for detection of anti-Toxoplasma gondii IgG antibodies in human serum. Input: patient serum sample. Process: serum incubated in polystyrene microtiter wells coated with purified Toxoplasma gondii antigen; captured IgG detected via goat anti-human IgG (Fc) conjugated to horseradish peroxidase; chromogen (tetramethylbenzidine) added to produce color reaction proportional to antibody concentration. Output: photometric absorbance measured at 450/630 nm. Used in clinical laboratory settings by trained personnel. Results aid clinicians in diagnosing Toxoplasma infection by identifying seroconversion or significant antibody titer rise in paired acute/convalescent sera.

Clinical Evidence

Clinical study of 294 serum samples from 263 individuals (infants, transplant patients, immunocompromised, pregnant women). Compared INCSTAR kit to Gull Toxoplasma IgG ELISA. Results: relative sensitivity 97-100%, relative specificity 95-100%, overall agreement 97-100% (95% CI). Additional studies included correlation, prevalence, cross-reactivity, interference, linearity, and precision.

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 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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K963257

# I. SUMMARY OF SAFETY AND EFFECTIVENESS

DEC 16 1996

**DEVICE NAME:** INCSTAR Toxoplasma IgG “fast” 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 “fast” ELISA kit contains instructions and materials for the 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 “fast” ELISA test is of value in the determination 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 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.

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# I. SUMMARY OF SAFETY AND EFFECTIVENESS (continued)

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 "fast" 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, 294 serum samples represented by 263 individuals were tested with the INCSTAR Toxoplasma IgG "fast" 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 97% to 100% and relative specificity of 95% to 100%. In addition, the assay displayed an overall agreement of 97% to 100%.

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