(158 days)
For the detection of human IgG antibodies to toxoplasma virus in human serum by enzyme immunoasay, to aid in the serological assessment of single samples and the diagnosis of primary infection in paired sera through the detection of Seroconversion of Toxoplasma specific IgG antibody. These reagents have not received FDA clearance for use in testing blood or plasma donors.
he SeraQuest™ Toxoplasma IgG test is a solid phase enzyme immunoassay (EIA), which is performed in microwells, at room temperature, in three thirty-minute incubations. It has been developed to detect IgG antibodies which are directed against Toxoplasma gondii in human serum.
Here's an analysis of the provided text regarding the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state pre-defined acceptance criteria for sensitivity, specificity, or overall agreement. Instead, it reports the observed performance of the SeraQuest™ Toxoplasma IgG test relative to the predicate device.
| Performance Metric | Acceptance Criteria (Not explicitly stated, assumed to be >90% based on typical IVD performance requirements for substantial equivalence) | Reported Device Performance (SeraQuest™ Toxoplasma IgG vs. INCSTAR Toxoplasma IgG Clin-ELISA™) |
|---|---|---|
| Relative Sensitivity | (Assumed > 90%) | 98.8 % to 100 % (95 % C.I.) |
| Relative Specificity | (Assumed > 90%) | 93.6 % to 100 % (95 % C.I.) |
| Overall Agreement | (Assumed > 90%) | 95.5 % to 100 % (95 % C.I.) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 143 sera
- Data Provenance: The samples were from "normal blood donors." The country of origin is not specified, but the applicant (Quest International, Inc.) is based in the US (North Miami, FL). The study appears to be retrospective as it uses pre-existing "sera from normal blood donors."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
This information is not applicable to this type of study. The ground truth for the SeraQuest™ Toxoplasma IgG test was established by comparing its results to a predicate device (INCSTAR Toxoplasma IgG Clin-ELISA™ kit), not through expert consensus or independent clinical assessment. The predicate device itself serves as the "ground truth proxy" in this context.
4. Adjudication Method for the Test Set
This information is not applicable. Since the comparison is against another diagnostic kit, there is no human "adjudication" in the sense of multiple experts independently evaluating cases. The results from the two devices are directly compared.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study compares the performance of one diagnostic device (SeraQuest™ Toxoplasma IgG) to a predicate device (INCSTAR Toxoplasma IgG Clin-ELISA™) in a standalone manner, not involving an assessment of human reader improvement with or without AI assistance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance study was done. The study evaluates the SeraQuest™ Toxoplasma IgG device itself against a predicate device, without involving human interpretation of the SeraQuest™ results. The output of the SeraQuest™ device (positive, negative, equivocal) is directly compared to the predicate device's output.
7. The Type of Ground Truth Used
The "ground truth" for this study was the results obtained from the predicate device, the INCSTAR Toxoplasma IgG Clin-ELISA™ kit. This is a form of comparative truth, where one established diagnostic method is used as the reference standard to evaluate a new method.
8. The Sample Size for the Training Set
The document does not specify the sample size for any training set. This is typical for a 510(k) summary for an in vitro diagnostic (IVD) kit that is not an AI/ML device. The "development" of such a kit usually involves analytical studies and in-house validation, but a defined "training set" in the machine learning sense is not applicable or detailed here. This is a traditional immunoassay, not an AI model.
9. How the Ground Truth for the Training Set Was Established
This information is not applicable as there is no mention of a "training set" in the context of an AI/ML model. For this type of traditional diagnostic kit, the "ground truth" for its development would involve internal validation using characterized samples (e.g., confirmed positive and negative clinical samples, reference materials). However, the document does not detail this.
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JUN 17 1996
APPENDIX 8.
Quest International, Inc., 1938 N.E. 148th Terrace, N. Miami, FL 33181 Page No. 183
510(k) SUMMARY
Quest International, Inc. Applicant: 1938 N.E. 148th Terrace North Miami, FL 33181
December 26, 1995 Date prepared:
Contact person: Robert A. Cort. President
Telephone: (305) 948-8788
Telefax: (305) 948-4876
Device: SeraQuest™ Toxoplasma IgG
Device Classification: Class II (performance standards)
Device Name: Toxoplasma serological reagents (21CFR § 866.3780) .
Description:
he SeraQuest™ Toxoplasma IgG test is a solid phase enzyme immunoassay (EIA), which is performed in microwells, at room temperature, in three thirty-minute incubations. It has been developed to detect IgG antibodies which are directed against Toxoplasma gondii in human serum.
Principle:
Diluted samples are incubated in antigen-coated wells. Toxoplasma antibodies (if present) are immobilized in the wells. Residual sample is eliminated by washing and conjugate (enzyme-labeled antibodies to human IgG) is added and incubated. If IgG antibodies to Toxoplasma are present, the conjugate will be immobilized in the wells. Residual conjugate is eliminated by washing and draining, and the substrate is added and incubated. In the presence of the enzyme, the substrate is converted to a yellow end product which is read photometrically.
Intended Use:
For the detection of human IgG antibodies to toxoplasma virus in human serum by enzyme immunoasay, to aid in the serological assessment of single samples and the diagnosis of primary infection in paired sera through the detection of Seroconversion of Toxoplasma specific IgG antibody. These reagents have not received FDA clearance for use in testing blood or plasma donors.
Predicate device:
The SeraQuest™ Toxoplasma IgG test has been shown to be substantially equivalent to the xoplasma IgG Clin-ELISA™ kit, INCSTAR Corporation, Stillwater Minnesota.
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| Summary of technological characteristics: | ||
|---|---|---|
| Characteristic | SeraQuest™ Toxoplasma IgG | INCSTAR Toxo IgG Clin-ELISA™ |
| Description: | Enzyme Immunoassay | Enzyme Immunoassay |
| Intended Use: | The detection of IgGantibodies against Toxoplasmagondii in human serum. | The detection of IgGantibodies against Toxoplasmagondii in human serum. |
| Antigen Strain | RH | RH |
| Solid Phase: | Plastic Microwell | Plastic Microwell |
| Number of Incubation Periods: | Three | Three |
| Sample Dilution: | 1:51 | 1:51 |
| Sample Volume: | 100 μl | 200 μl |
| Sample IncubationDuration: | 30 minutes | 30 minutes |
| incubation Temperature: | Room temperature | Room temperature |
| Ezyme-labeled Conjugate: | ||
| Antibody | Goat anti-human IgG | Goat or Sheep anti-human IgG |
| Enzyme | Alkaline phosphatase | Alkaline phosphatase |
| Conjugate Volume: | 100 μl | 200 μl |
| Conjugate IncubationDuration: | 30 minutes | 30 minutes |
| Substrate: | p-Nitrophenylphosphate | p-Nitrophenylphosphate |
| Subtrate Volume: | 100 μl | 200 μl |
| Substrate IncubationDuration: | 30 minutes | 45 minutes |
| Stop Reagent: | 0.5 M Trisodiumphosphate | 3 N SodiumHydroxide |
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Stop Reagent Volume:
100 ul
405 nm
50 ul
Aeadout:
Spectrophotometric
Spectrophotometric 405 nm
Summary of Clinical Testing:
One hundred and forty-three sera from normal blood donors were assayed for the presence of Toxoplasma IgG antibodies, using the SeraQuest™ Toxoplasma IgG test and the INCSTAR Toxoplasma IgG Clin-ELISA™ test. Of the one hundred and forty-three specimens tested, forty-one were positive, and ninety-six were negative, by both tests. Of the six remaining specimens, three were positive in The SeraQuest™ test and negative in the comparative test, one was positive in the SeraQuest™ test and equivocal in the comparative test, and two specimens were equivocal in the SeraQuest™ test and negative in the comparative test. Excluding the equivocal results, the sensitivity and specificity, of the SeraQuest™ test relative to the INCSTAR Toxoplasma IgG Clin-ELISA™ test, was 98.8 % to 100 % (95 % C.I.) and 93.6 % to 100 % (95 % C.I.), respectively. The overall agreement was 95.5 % to 100 % (95 % C.I.). These results are shown below in Table 1.
Table 1. Results of Comparative Testing of 143 Serum Specimens, Using the SeraQuest™ Toxoplasma IgG Test and the INCSTAR Toxoplasma IgG Clin-ELISA™ Test.
| INCSTARToxoplasma IgG | SeraQuest Toxoplasma IgG | |||
|---|---|---|---|---|
| Positive | Equivocal | Negative | 95 % Confidence Interval* | |
| Positive | 41 | 0 | 0 | Relative sensitivity√ 98.8 to 100 |
| Equivocal | 1 | 0 | 0 | |
| Negative | 2 | 3 | 96 | Relative specificity√ 93.6 to 100Overall agreement√ 95.5 to 100 |
Excluding equivocal results.
Calculated by the normal method.
§ 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).