For the qualitative, semi-quantitative and quantitative detection of human IgG antibodies to dsDNA in human serum by enzyme immunoassay, as an aid in the diagnosis systemic lupus erythematosus (SLE). For manual use, or for use with the HyPrep System Plus. For In Vitro Diagnostic Use Only.

For in vitro diagnostic use only.
For the qualitative, semi-quantitative and quantitative detection of IgG antibodies to dsDNA in human serum by enzyme immunoassay.
For use as an aid in the diagnosis of systemic lupus erythematosus (SLE).
For manual use, or for use with the HyPrep System Plus semi-automated fluid handler.

Device Description

The SeraQuest Anti-dsDNA 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 dsDNA, in human serum.

The Calibrators in the SeraQuest Anti-dsDNA test set have been assigned IU/ml values which are traceable to the WHO First International Standard for Anti-Double-Stranded DNA, Wo-80, and Index values which based on an in-house standard anti-dsDNA serum. Test results are reported as IU/ml or as Index values.

Diluted samples are incubated in wells coated with dsDNA antibodies against ds DNA (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 DSDNA are present, the conjugate will be immobilized in the wells. Residual conjugate is eliminated by washing and draining, and the enzyme substrate is added and incubated. In the presence of the enzyme, the substrate is converted to a yellow end-product which is read photometrically at 405 nm.

AI/ML Overview

Here's an analysis of the provided text to extract information about the acceptance criteria and the study that proves the device meets those criteria:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined acceptance criteria in terms of specific sensitivity, specificity, or agreement percentages that the SeraQuest Anti-dsDNA device must meet. Instead, the study's performance is presented relative to a predicate device (Shield DIASTAT Anti-dsDNA kit). The de facto acceptance criteria appears to be a demonstration of substantial equivalence to this predicate.

Based on the "Summary of Clinical Testing" and "TABLE 1" which presents the comparative results between the SeraQuest Anti-dsDNA and the predicate Shield DIASTAT Anti-dsDNA, here's a table of the reported device performance:

Performance Metric	SeraQuest Anti-dsDNA Performance (compared to Shield DIASTAT Anti-dsDNA)	Acceptance Criteria (Implicit - Substantial Equivalence to Predicate)
Relative Sensitivity*	92.8% (95% CI: 86.6 to 98.9)	Demonstrated to be comparable to predicate (Shield DIASTAT Anti-dsDNA)
Relative Specificity*	97.7% (95% CI: 95.1 to 100)	Demonstrated to be comparable to predicate (Shield DIASTAT Anti-dsDNA)
Overall Agreement*	96.0% (95% CI: 93.2 to 98.7)	Demonstrated to be comparable to predicate (Shield DIASTAT Anti-dsDNA)

*Excluding equivocal results.

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

Sample Size for Test Set: 215 serum specimens.
Data Provenance: The study was performed "at Quest International, Inc. Miami, FL." The document does not specify the country of origin of the patients from which these specimens were obtained. It is a retrospective study comparing a new device against an existing one using collected specimens.

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

The document does not mention the use of experts to establish a "ground truth" for the test set in the traditional sense (e.g., independent adjudication of disease status). Instead, the comparison is made against a predicate device (Shield DIASTAT Anti-dsDNA kit). The predicate device's results are used as the reference point for calculating relative sensitivity, specificity, and agreement.

However, the context for some samples is mentioned: "{ } Number of patients with clinically diagnosed SLE." This implies a clinical diagnosis made by medical professionals, but the specific number of experts or their qualifications for establishing these clinical diagnoses are not detailed.

4. Adjudication Method for the Test Set

There was no explicit adjudication method described for the test set. The study directly compares the results of the SeraQuest Anti-dsDNA assay with the Shield DIASTAT Anti-dsDNA assay. Discrepancies between the two tests were reported (e.g., 25 specimens equivocal in SeraQuest, 11 equivocal in Shield, 3 positive in SeraQuest and negative in Shield, 5 positive in Shield and negative in SeraQuest), but no adjudication process to resolve these was detailed or used to modify the reported performance metrics. The metrics were calculated based on direct comparison.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done

No, an MRMC comparative effectiveness study was not conducted. This study is an in vitro diagnostic device assessment comparing the performance of two laboratory assays, not a study evaluating human reader performance 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 assessment was done. The "SeraQuest Anti-dsDNA" device itself is an enzyme immunoassay (a laboratory test) that provides results (qualitative, semi-quantitative, and quantitative detection of IgG antibodies to dsDNA). Its performance as a standalone assay was evaluated by comparing its results directly to those of a predicate assay, not by evaluating human interaction with the device.

7. The Type of Ground Truth Used

The primary "ground truth" for evaluating the SeraQuest Anti-dsDNA device's performance was the results from the predicate device, the Shield DIASTAT Anti-dsDNA kit. This is a comparative study against a legally marketed device.

Secondary information, such as "Number of patients with clinically diagnosed SLE" (mentioned in brackets in Table 1), indicates that some samples had an associated clinical diagnosis (outcomes data/expert consensus for disease status). This clinical diagnosis data helps contextualize the results for some samples but is not the primary "ground truth" against which the device's numerical performance metrics (sensitivity, specificity, agreement) were calculated in this table.

8. The Sample Size for the Training Set

The document does not describe a "training set" in the context of machine learning or algorithm development. This is a traditional in vitro diagnostic device submission for an immunoassay. Therefore, this concept is not applicable here. The assay's parameters would have been developed and optimized prior to this validation study, but no specific "training set" size for that optimization is provided.

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

As noted in point 8, the concept of a "training set" with established ground truth is not applicable to this type of device submission. The device is a laboratory assay, and its performance is validated against a predicate device using a test set of specimens.

Summary

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APPENDIX 3. (revised 4/10/98)

APR 2 4 1998

510(k) SUMMARY

K980391

Applicant:	Quest International, Inc.1938 N.E. 148th TerraceNorth Miami, FL 33181
Registration No.	1061839
Contact Person:	Robert A. Cort, V.P. , Quality Assurance
Telephone:	(305) 948-8788
Telefax:	(305) 948-4876
Manufacturing Site:	Same as above
Device:	SeraQuest® Anti-dsDNA
Device Name:	Anti-nuclear antibody immunological test system (21CFR § 866.5100)Systemic lupus erythematosus immunological test system(21CFR § 866.5620)

Tevice Classification: Class II (performance standards)

Description:

Principle:

{1}------------------------------------------------

ntended Use:

(

Predicate Device:

The SeraQuest Anti-dsDNA test is substantially equivalent in intended use and performance, to the Shield DIASTAT Anti-dsDNA kit, Shield Diagnostics, Dundee, UK.

Summary of technological characteristics:

Characteristic	SeraQuest Anti-dsDNA	Shield Anti-dsDNA
Description:	Enzyme Immunoassay	Enzyme Immunoassay
Intended Use:	The detection of IgGantibodies against dsDNAin human serum.	The detection of IgG & IgMantibodies against dsDNAin human serum.
Solid Phase:	Plastic Microwell	Plastic Microwell
Antigen:	Calf Thymus DNA	Calf Thymus DNA
Number of Incubation Periods:	Three	Three
Sample Dilution:	1:50	1:100
Sample IncubationDuration:	30 minutes	60 minutes
Incubation Temperature:	Room temperature	Room temperature
Ezyme-labeled Conjugate:
Antibody	Goat anti-human IgG	Goat anti-human IgG & IgM
Enzyme	Alkaline phosphatase	Alkaline phosphatase
Conjugate Volume:	100 µl	100 µl
Conjugate Incubation Duration:	30 minutes	30 minutes
Substrate:	p-Nitrophenylphosphate	phenolphthaleinmonophosphate

{2}------------------------------------------------

Subtrate Volume:	100 µl	100 µl
Substrate IncubationDuration:	30 minutes	30 minutes
Stop Reagent:	0.5 M Trisodiumphosphate	Sodium Hydroxide
Stop Reagent Volume:	100 µl	100 µl
Readout:	Spectrophotometric405 nm	Spectrophotometric550 nm

Summary of Clinical Testing:

Of 215 specimens tested, 64 were positive, 126 were negative and 1 was equivocal in both the SeraQuest and Shield tests (Table 1 below). Of the 25 remaining specimens were equivocal in the SeraQuest test and of these, 2 were positive and 3 were negative by the Shield test: 11 specimens were equivocal by the Shield test and of these, 4 were positive and 7 were negative by the SeraQuest test; 3 specimens which were positive by the SeraQuest test were negative by the Shield test, and 5 specimens which were positive by the Shield test were negative by the SeraQuest test.

ГАВLE 1.

RESULTS OF SeraQuest ANTI-dsDNA ASSAYS AND SHIELD DIASTAT ANTI-dsDNA ASSAYS OF 215 SERUM SPECIMENS, PERFORMED AT QUEST INTERNATIONAL, INC. MIAMI, FL.

SHIELDDIASTATANTI-dsDNA		SeraQuest ANTI-dsDNA				%
	Positive	Equivocal	Negative
Positive	64 {36}	2	5	Relative sensitivity*	92.8	86.6 to 98.9
Equivocal	4 {2}	1	7 {1}
Negative	3 {1}	3 {2}	126 {8}	Relative specificity*	97.7	95.1 to 100
Overall agreement*					96.0	93.2 to 98.7

{ } Number of patients with clinically diagnosed SLE.

Exeluding equivasel results

Excluding equivocal results.
Calculated by the normal method.

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APR 2 4 1998

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Mr. Robert A. Cort Vice President, Quality Assurance Quest International, Inc. 1938 N.E. 148th Terrace North Miami, Florida 33181

Re : K980391/S1 Trade Name: SeraQuest® Anti-dsDNA Requlatory Class: II Product Code: LRM Dated: April 14, 1998 Received: April 17, 1998

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 requlation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP requlation 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 Requlations.

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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 requlation 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 Putman

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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Quest International, Inc., 1938 N.E. 148th Terrace, N. Miami, FL 33181 Page No. 137

APPENDIX 6 (revised 4/10/98)

Page _________________________________________________________________________________________________________________________________________________________________________

510(k) Number (if known): K980391

Device Name: _ SeraQuest Anti-dsDNA

Indications For Use:

For in vitro diagnostic use only. 1.
For the qualitative, semi-quantitative and quantitative detection of IgG antibodies 2. to dsDNA in human serum by enzyme immunoassay.
For use as an aid in the diagnosis of systemic lupus erythematosus (SLE). 3.

ﺔ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤ

For manual use, or for use with the HyPrep System Plus semi-automated fluid 4. handler.
(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use
(Per 21 CFR 801.109) OR Over-The-Counter Use

(Optional Format 1-2-96)

Regulation Number and Section

§ 866.5100 Antinuclear antibody immunological test system.

(a)
Identification. An antinuclear antibody immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the autoimmune antibodies in serum, other body fluids, and tissues that react with cellular nuclear constituents (molecules present in the nucleus of a cell, such as ribonucleic acid, deoxyribonucleic acid, or nuclear proteins). The measurements aid in the diagnosis of systemic lupus erythematosus (a multisystem autoimmune disease in which antibodies attack the victim's own tissues), hepatitis (a liver disease), rheumatoid arthritis, Sjögren's syndrome (arthritis with inflammation of the eye, eyelid, and salivary glands), and systemic sclerosis (chronic hardening and shrinking of many body tissues).(b)
Classification. Class II (performance standards).