(117 days)
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.
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 antihuman 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 IqG bound to the solid phase.
{
"acceptance_criteria_and_performance": {
"table": {
"Acceptance Criteria (Implicit)": [
"Relative Sensitivity",
"Relative Specificity",
"Overall Agreement"
],
"Reported Device Performance": [
"98% to 100%",
"92% to 99%",
"96% to 99%"
]
},
"study_description": "In clinical performance studies, 300 serum samples representing 269 individuals were tested with the INCSTAR Toxoplasma IgG Kit and results were compared to those generated from the Gull Toxoplasma IgG ELISA kit. This comparison allowed for the determination of relative sensitivity, specificity, and overall agreement, demonstrating that the device meets an implied acceptance criteria if these values fall within an acceptable range, which they appear to do given the confidence intervals."
},
"sample_size_and_provenance": {
"test_set_sample_size": "300 serum samples representing 269 individuals",
"data_provenance": "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. The country of origin is not specified, but the context implies a clinical setting."
},
"number_and_qualifications_of_experts_for_ground_truth": "Not applicable, as ground truth was established by comparison to a cleared predicate device rather than expert consensus on individual cases.",
"adjudication_method": "Not applicable, as ground truth was established by comparison to a cleared predicate device.",
"mrmc_comparative_effectiveness_study": "No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly mentioned. The study compares the device's performance to a predicate device, rather than human readers with and without AI assistance.",
"standalone_performance_study": "Yes, a standalone performance study was done in the sense that the INCSTAR Toxoplasma IgG ELISA Kit's performance was evaluated independently against the predicate device. The reported sensitivity, specificity, and agreement are measures of its standalone performance in comparison to a reference standard.",
"type_of_ground_truth": "The ground truth was established by comparison to the Gull Toxoplasma IgG ELISA kit (510(k) No. [K915891](https://510k.innolitics.com/search/K915891)), which is described as an \"FDA cleared\" and \"currently in U.S. commercial distribution\" predicate device. This implies the predicate device serves as the reference standard for defining positive and negative cases.",
"training_set_sample_size": "Not specified. The document describes a comparison study using 300 samples, but does not detail a separate training set size for the development of the INCSTAR Toxoplasma IgG ELISA Kit.",
"how_training_set_ground_truth_established": "Not specified. The document focuses on the performance study of the completed device against a predicate, rather than the development or training phase of the device."
}
§ 866.3780
Toxoplasma gondii serological reagents.(a)
Identification. Toxoplasma gondii serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies toToxoplasma gondii in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to identifyToxoplasma gondii from clinical specimens. The identification aids in the diagnosis of toxoplasmosis caused by the parasitic protozoanToxoplasma 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.(b)
Classification. Class II (performance standards).