For the qualitative, semi-quantitative, and quantitative detection of IgM antibodies to Toxoplasma gondii in human serum by enzyme immunoassay, to aid in the diagnosis of Toxoplasma infection.
A positive result is presumptive for the detection of anti-Toxoplasma gondii antibodies and presumptive for the diagnosis of acute, recent or reactivated Toxoplasma gondii infection.
Patient testing with the SeraQuest Toxoplasma IgM assay must be accompanied by an anti-toxoplasma IgG antibody assay.
Useful for the above indications, with specimens obtained from women of childbearing age and during pregnancy.
For manual use, or for use with the HyPrep System Plus semi-automated fluid handler.

Device Description

The SeraQuest Toxoplasma IdM test is a solid-phase enzyme immunoassay (ElA), which is erformed in microwells, at room temperature, in three thirty minute incubations. It has been seveloped to detect IdM antibodies which are directed against Toxoplasma gondii, in human serum. The Calibrators in the SeraQuest Toxoplasma IgM test set have been assigned Index values based on an in-house standard, and International Units (IU/ml) based on the WHO Anti-toxoplasma Serum, Human, (3rd international standard preparation). Test results are reported as Index values, or IU/ml.

AI/ML Overview

Here's an analysis of the provided text, outlining the acceptance criteria and study details for the SeraQuest Toxoplasma IgM device:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined acceptance criteria with specific numerical thresholds for sensitivity, specificity, or overall agreement. However, it does present the results of a comparison study against a predicate device, which implicitly serves as the performance benchmark for market clearance due to substantial equivalence.

Metric	Acceptance Criteria (Implied by Predicate Equivalence)	Reported Device Performance (SeraQuest Toxoplasma IgM vs. INCSTAR Toxoplasma IgM Clin-ELISA™)
Relative Sensitivity (to Predicate)	Substantially equivalent to predicate device	74.3% to 92.9% (95% CI)
Relative Specificity (to Predicate)	Substantially equivalent to predicate device	86.8% to 99.6% (95% CI)
Overall Agreement (to Predicate)	Substantially equivalent to predicate device	82.6% to 94.1% (95% CI)

2. Sample Size Used for the Test Set and Data Provenance

Sample Size for Test Set: 128 archival serum specimens.
Data Provenance:
- Country of Origin: Not explicitly stated, but the study was performed "in-house at Quest International, Inc., Miami, FL," suggesting it was likely U.S.-sourced or a mix of sources available to them.
- Retrospective or Prospective: Retrospective. The specimens were "archival serum specimens" and included pre-existing categories like "normal, asymptomatic donors," "women being tested prenatally," "specimens reported to be positive for IgM antibodies to toxoplasma which were obtained from serum brokers," and "acute toxoplasma infections."

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

The concept of "ground truth" as established by experts in the context of diagnostic device submissions often refers to a definitive diagnosis determined by a gold standard method. In this case, the study compares the SeraQuest device against a predicate device (INCSTAR Toxoplasma IgM Clin-ELISA™). This means the "ground truth" for the performance metrics (sensitivity, specificity, agreement) is relative to the results of the INCSTAR assay.

When discordant results were found between the SeraQuest and INCSTAR tests, "specimens giving discordant results were tested with a second legally marketed device, along with a representative number of positive and negative samples which gave concordant results." This implies a form of re-testing or confirmatory testing was used to resolve discrepancies, but it does not explicitly state that human experts were involved in establishing the final ground truth from these multiple tests, nor does it specify the number or qualifications of such experts if they were. The ultimate "ground truth" used for calculating sensitivity, specificity, and agreement was the INCSTAR predicate device's result (as indicated by the terminology "relative sensitivity" and "relative specificity" to the INCSTAR test).

4. Adjudication Method for the Test Set

The primary comparison was against the INCSTAR Toxoplasma IgM Clin-ELISA™ test. For discordant results, "specimens giving discordant results were tested with a second legally marketed device."

This suggests an implied adjudication method where:

SeraQuest results were compared to Incstar.
If SeraQuest and Incstar agreed, that was the result.
If SeraQuest and Incstar disagreed, a "second legally marketed device" was used to help resolve the discrepancy.
- The document doesn't explicitly state how the final determination was made after testing with the second legally marketed device (e.g., if it was 2-out-of-3 agreement, or if one test was considered the ultimate arbiter among the three). However, the performance metrics reported are relative to the INCSTAR test, implying INCSTAR was still the primary reference.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done, If So, What was the Effect Size of How Much Human Readers Improve with AI vs Without AI Assistance

No Multi-Reader Multi-Case (MRMC) Study was Done: This is a diagnostic assay (chemical/biological test kit), not an imaging or AI-driven diagnostic device that would typically involve human readers interpreting results or being assisted by AI. The device directly produces readings (Index values or IU/ml) which are then interpreted as positive, negative, or equivocal. Therefore, this section is not applicable.

6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done

Yes, a standalone study was done. The SeraQuest Toxoplasma IgM test is an enzyme immunoassay (EIA) that directly produces a result (spectrophotometric reading at 405 nm). The reported performance (sensitivity, specificity, agreement) is for the device operating independently to detect IgM antibodies, using its own defined cut-offs for positive/negative/equivocal, and then compared to the predicate device, also operating as a standalone test. There is no concept of a "human-in-the-loop" for interpreting the primary output of this type of immunoassay when comparing its performance against another immunoassay.

7. The Type of Ground Truth Used

The primary "ground truth" for performance evaluation was the results from a legally marketed predicate device, the INCSTAR Toxoplasma IgM Clin-ELISA™ kit. For discordant results, a "second legally marketed device" was used for further analysis, implying a form of comparative testing against established diagnostic assays rather than a histopathological "gold standard" or patient outcomes data.

8. The Sample Size for the Training Set

The document does not explicitly mention a "training set" in the context of machine learning or algorithm development. For this type of immunoassay, development generally involves optimization and validation against characterized samples, but not typically a "training set" as understood in AI/ML. The 128 specimens are referred to as "clinical testing" and appear to be the primary validation set used for the substantial equivalence demonstration.

9. How the Ground Truth for the Training Set Was Established

As a training set is not explicitly identified or described, this question is not fully applicable. If indirectly referring to the method used to establish the "truth" for samples used in the overall development and validation of the assay (which might include samples used to define assay cutoffs prior to the formal clinical study), the document doesn't specify this for those hypothetical antecedent steps. The closest information available is how the predicate comparison study's "truth" was established, which was through comparison to another legally marketed device (INCSTAR).

Summary

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Quest International, Inc., 1938 N.E. 148th Terrace, N. Miami, FL 33181 Page No. Jorge

APPENDIX 5.

510(k) SUMMARY

Applicant:	Quest International, Inc.1938 N.E. 148th TerraceNorth Miami, FL 33181
Date prepared:	May 1, 1997
Contact person:	Robert A. Cort, President
Telephone:	(305) 948-8788
Telefax:	(305) 948-4876
Device:	SeraQuest Toxoplasma IgM
Device Classification:	Class II (performance standards)
Device Name:	Toxoplasma serological reagents (21CFR § 866.3780)

Description:

Principle:

Diluted samples are incubated in wells coated with Toxoplasma gondii antibodies directed against toxoplasma (if present) are immobilized in the wells. Residual sample is eliminated by washing and draining, and conjugate (enzyme-labeled antibodies to human IgM) is added and incubated. If IgM antibodies to Toxoplasma are present, the conjugate will be immobilized in the wells. Residual conjugate is eliminated by washing and the enzyme substrate is added and incubated. In the presence of the enzyme, the substrate is converted to a yellow endproduct which is read photometrically at 405 nm.

Intended Use:

For the quantitative, semi-quantitative and qualitative detection of human IgM antibodies to Toxoplasma in human serum by enzyme immunoassay, to aid in the diagnosis of Toxoplasma infection. A positive result is presumptive for the detection of anti-Toxoplasma gondii antibodies and presumptive for the diagnosis of acute, recent, or reactivated Toxoplasma gondii infection. Patient testing with the anti-Toxoplasma gondi IgM antibody assay, must be accompanied by a anti-

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APPENDIX 5.

xoplasma gondi IgG antibody assav. For manual use, or for use with the HyPrep System Plus. ithis assay has not been cleared / approved by the FDA for blood / plasma donor screening. For In Vitro Diagnostic Use Only. Please see Indications for Use form, Appendix 11.

Predicate device:

The SeraQuest Toxoplasma IgM test has been shown to be substantially equivalent to the Toxoplasma IgM Clin-ELISA™ kit, INCSTAR Corporation, Stillwater Minnesota.

Summary of technological characteristics:

Characteristic	SeraQuest Toxoplasma IgM	INCSTAR Toxo IgM Clin-ELISA™
Description:	Enzyme Immunoassay	Enzyme Immunoassay
Intended Use:	The detection of IgMantibodies against Toxoplasmagondii in human serum.	The detection of IgMantibodies against Toxoplasmagondii in human serum.
Antigen Strain	RH	RH
Solid Phase:	Plastic Microwell	Plastic Microwell
'umber of Incubation Periods:	Three	Three
Sample Dilution:	1:26	1:51
Sample Volume:	100 μl	200 μl
Sample PretreatmentDuration:	None	30 minutes
Sample IncubationDuration:	30 minutes	30 minutes
Incubation Temperature:	Room temperature	Room temperature
Ezyme-labeled Conjugate:
Antibody	Goat anti-human IgM	Goat or Sheep anti-human IgM
Enzyme	Alkaline phosphatase	Alkaline phosphatase
Conjugate Volume:	100 μl	200 μl
Conjugate IncubationDuration:	30 minutes	30 minutes
Substrate:	p-Nitrophenyl phosphate	p-Nitrophenyl phosphate
Substrate Volume:	100 μl	200 μl
Substrate Incubation Duration:	30 minutes	45 minutes
Stop Reagent:	0.5 M Trisodium phosphate	3 N Sodium Hydroxide
Stop Reagent Volume:	100 μl	50 μl
Readout:	Spectrophotometric 405 nm	Spectrophotometric 405 nm
Summary of Clinical Testing:

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APPENDIX 5.

Experimental Procedure

One hundred and twenty-eight archival serum specimens including: 24 specimens from normal, asymptomatic donors, 38 specimens from women being tested prenatally for antibodies to toxoplasma and 16 specimens reported to be positive for IgM antibodies to toxoplasma which were obtained from serum brokers, and 50 specimens from acute toxoplasma infections, were tested at 'uest International, Inc., concurrently by the SeraQuest Toxoplasma IgM test and the INCSTAR . oxoplasma IgM Clin-ELISA™ test. The assays were performed and interpreted according to the manufacturers package inserts. Specimens giving discordant results were tested with a second legally marketed device, along with a representative number of positive and negative samples which gave concordant results by both test methods.

Results and Conclusion

Of the 128 specimens tested, 51 were positive, and 55 were negative in both the SeraQuest and Incstar tests (please see Table 1). Of the 22 remaining specimens which were negative by the Incstar test were positive by the SeraQuest test, and 10 specimens which were positive by the Incstar test were negative in the SeraQuest test. The remaining 8 specimens gave equivocal results in one or both of the assays being compared. Of 5 specimens which were equivocal in the SeraQuest assay 4 were positive and 1 was negative in the Incstar assay, and of 3 specimens which were equivocal in the Incstar assay. 1 was positive and 2 were negative by the SeraQuest test.

Excluding the equivocal results, the sensitivity and specificity expressed as 95% confidence intervals (95% Cl), of the SeraQuest Toxoplasma IgM test relative to the INCSTAR Toxoplasma IgM Clin-ELISA™ test, were 74.3 to 92.9% and 86.8 to 99.6% respectively. The overall agreement was 82.6 to 94.1%.

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APPENDIX 5. ABLE 1.

ASSAYS, TOXOPLASMA laM AND INCSTAR RESULTS OF OF SeraQuest Clin-ELISA ASSAYS, OF SPECIMENS. 128 SERUM THE TOXOPLASMA IgM SPECIMENS INCLUDED: 24 SPECIMENS FROM NORMAL ASYMPTOMATIC 38 SPECIMENS FROM WOMEN BEING SCREENED PRENATALLY FOR DONORS: TOXOPLASMA ANTIBODIES; 16 SPECIMENS REPORTED TO BE POSITIVE FOR IgM ANTIBODIES TO TOXOPLASMA, WHICH WERE OBTAINED FROM SERUM BROKERS; AND 50 ACUTE PHASE SPECIMENS OBTAINED FROM TOXOPLASMA INFECTIONS. THESE TESTS WERE PERFORMED IN-HOUSE AT QUEST INTERNATIONAL, INC., MIAMI, FL.

INCSTAR	SeraQuest Toxoplasma IgM
Toxoplasma IgM	Positive	Equivocal Negative		95 % Confidence Interval
Positive	51	ব	10	Relative sensitivity* 74.3 to 92.9√√
Equivocal	r	0	ર્ય
Negative	ব		રે રે	Relative specificity* 86.8 to 99.6vV
				Overall agreement*	82.6 to 94.1VV

Excluding equivocal results.

VV Calculated by the normal method. (see Reference below).

Reference: Gardner, M.J. and Altman, D.G., Confidence Intervals Rather Than Hypothesis Testing. Brit. Med. J., 292: 746-750. 1986.

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Image /page/4/Picture/2 description: The image shows the seal of the Department of Health & Human Services USA. The seal is circular, with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" arranged around the top half of the circle. In the center of the seal is a stylized image of an eagle, with its wings spread. The eagle is facing to the right. The seal is black and white.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

OCT 2 1 1997

· Robert A. Cort Vice President, Quality Assurance Ouest International 1938 N.E. 148th Terrace North Miami, FL 33181

Re: K971672

Trade Name: SeraQuest Toxoplasma IgM Regulatory Class: II Product Code: LGD Dated: August 6, 1997 Received: August 6, 1997

Dear Mr. Cort:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (OS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal Laws or Regulations.

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Page 2

Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88), this device may require a CLIA complexity categorization. To determine if it does, you should contact. the Centers for Disease Control and Prevention (CDC) at (770)488-7655.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll free number (800) 638-2041 or at (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html"

Sincerely yours.

Steven Autman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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APPENDIX 11

Quest International, Inc., 1938 N.E. 148th Terrace, N. Miami, FL 33181

Page 1 of

510(k) Number (if known): _ Kg 7-1672

Device Name: SeraQuest Toxoplasma IqM

Indications For Use:

For the qualitative, semi-quantitative, and quantitative detection of IgM 1. antibodies to Toxoplasma gondii in human serum by enzyme immunoassay, to aid in the diagnosis of Toxoplasma infection.
1. A positive result is presumptive for the detection of anti-Toxoplasma gondii antibodies and presumptive for the diagnosis of acute, recent or reactivated Toxoplasma gondii infection.
1. Patient testing with the SeraQuest Toxoplasma IgM assay must be accompanied by an anti-toxoplasma IgG antibody assay.
1. Useful for the above indications, with specimens obtained from women of childbearing age and during pregnancy.
ട. For manual use, or for use with the HyPrep System Plus semi-automated fluid handler.

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Jean Cooper

(Division Sign-Off)
Division of Clinical Laboratory Devices
510(k) Number K971672'

Prescription Use (Per 21 CFR 801.109)

Over-The-Counter Use_

(Optional Format 1-2-96)

Regulation Number and Section

§ 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).