This enzyme-linked immunosorbent assay (ELISA) is indicated for the detection of altoantilian to the antigen Myeloperoxidase (MPO) in human serum. The presence of MPO antibodies, in combination with dinical observations and other serological tests, can aid in the dlagnosis of polyarterits, necrotizing glomerulonephritis and other conditions associated with elevated anti-neutrophil cytoplasmic antibodies (ANCA).

Device Description

An enzyme-linked immunosorbent assay (ELISA) designed for the detection and measurement of autoantibodies to the antigen myeloperoxidase in human serum.

The ELISA methodology is commonly used for serum antibody evaluations. Purified MPO antigen has been attached to the inner surfaces of the microwell plate. During the initial incubation step, antibodies in patient serum bind specifically to the immobilized antigen and remain in place after a wash step.

A second antibody which is conjugated to horseradish peroxidase (HRP) is used to recognize the "heavy + light" chain regions of the patient's antibodies remaining after the wash step. In the wells where the second antibody remains bound, the conjugated HRP catalyzes a color change in the substrate, tetramethyl benzidine (TMB). After the reaction is stopped, the color is read in an EIA Plate reader.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study details for the K973824 device, based on the provided 510(k) summary:

1. Table of Acceptance Criteria and Reported Device Performance

The 510(k) summary for K973824 primarily focuses on demonstrating substantial equivalence to a predicate device rather than explicitly stating pre-defined acceptance criteria with numerical targets. However, the performance data presented implies the following implicit criteria for comparison with the predicate:

Acceptance Criteria Category	Specific Metric	Reported Device Performance (VIRGO® pANCA Kit)
Precision (Inter-assay)	%CV (OD)	Range from 4.2% to 11.0%
	%CV (Units)	Range from 6.3% to 11.7%
	Cutoff Serum %CV	10.1%
	Positive Control %CV	2.4%
Precision (Intra-assay)	%CV (OD)	Range from 4.0% to 8.5%
	Cutoff Serum %CV	6.4%
	Positive Control %CV	4.3%
Comparison Testing (Relative Sensitivity vs. Predicate)	pANCA Panel 1	100.0% (21/21), 0.85 CI: 84.5% to 100%
	pANCA Panel 2	100.0% (40/40), 0.88 CI: 91.2% to 100%
Comparison Testing (Relative Specificity vs. Predicate)	Normals	100% (62/62), 4.8 CI: 94.2% to 100%
Interfering Substances	Hemoglobin concentration	No significant effect (<15% variation) at ≤ 500 mg/dL
	Bilirubin concentration	No significant effect (<15% variation) at < 20 mg/dL
	Lipid concentration	No significant effect (<15% variation) at ≤ 3000 mg/dL
Prozone Effect	High titered sera	Kit gives appropriately high positive results

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

Comparison Testing:
- Total samples: 132 serum specimens.
- Breakdown:
  - 22 pANCA positive specimens (from throughout the United States).
  - 40 specimens from individuals demonstrating pauci-immune necrotizing and/or crescentic glomerulonephritis.
  - 70 specimens from normal apparently healthy donors.
- Provenance: Retrospective, as indicated by collecting "specimens taken from throughout the United States" and from "individuals demonstrating" certain conditions. The specific country of origin is "United States" for at least the pANCA positive samples.
Precision Studies:
- Inter-assay: 7 samples, assayed in duplicate twice a day for 5 days (70 individual measurements per sample set).
- Intra-assay: 7 samples, assayed 20 consecutive times in a single run (140 individual measurements per sample set).
- Provenance: Not explicitly stated, but typically these are controlled laboratory samples, not necessarily patient samples.
Interfering Substances: Specific number of samples not given, but mentioned as "Libemic, icteric, and hemolytic samples were evaluated."
Prozone: "several high titered serum samples" were used.

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

The document does not explicitly state the number of experts or their qualifications used to establish the ground truth for the test set.

4. Adjudication Method (e.g., 2+1, 3+1, none) for the Test Set

The document does not describe any specific adjudication method for establishing the ground truth of the test set. The ground truth for the comparison testing was based on the results of the "predicate device" and in eight discrepant cases, confirmed by a "third party IFA kit."

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, a Multi Reader Multi Case (MRMC) comparative effectiveness study was not done. This device is an in-vitro diagnostic (IVD) assay kit for laboratory use, not an AI-assisted diagnostic tool for human readers. Therefore, the concept of human readers improving with or without AI assistance does not apply.

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

This device is a standalone in-vitro diagnostic (IVD) assay kit. Its performance is evaluated biochemically (optical density measurements) rather than through an algorithm. The reported performance metrics (sensitivity, specificity, precision) reflect the device's standalone capability to detect and measure autoantibodies.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

The ground truth for the comparison testing was established using:

Results from the predicate device (Scimedx MPO ANTIBODY EIA Kit).
For discrepant samples (8 cases), confirmation was made by a third-party IFA kit.
The selection of samples also involved clinical categories: "pANCA positive specimens," "specimens from individuals demonstrating pauci-immune necrotizing and/or crescentic glomerulonephritis," and "normal apparently healthy donors." This implies a degree of clinical diagnosis informing the sample classification.

8. The Sample Size for the Training Set

The document does not specify a separate "training set" for the device development. IVD kits typically undergo development and optimization, but the concept of a distinct 'training set' as used in machine learning is not directly applicable or documented here. The reported "Performance Data" is for validation.

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

As no explicit training set is detailed, the method for establishing its ground truth is not applicable or provided. Device development and optimization for such kits usually involve internal standards, known positive/negative controls, and research samples.

Summary

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K973824

510(k) Summary

NOV 1 3 1997

Submitter's Name/Contact Person 1.

Joseph M. Califano Manager, Regulatory Affairs

Address

Hemagen Diagnostics, Inc. 34-40 Bear Hill Road Waltham, MA, 02154

(781) 890-3766 Phone: (781) 890-3748 Fax: jcalifano@hemagen.com email:

Date Prepared

30 September 1997

2. Device Name

Trade Name:	VIRGO ® pANCA Kit (EIA method)
Common Name:	MPO Antibody Kit
Classification Name:	Antineutrophil Cytoplasmic Antibodies test system

3. Predicate Device

Scimedx MPO Antibody EIA Kit {510 (k) Docket No. K 954062}

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Description of Device 3.

An enzyme-linked immunosorbent assay (ELISA) designed for the detection and measurement of autoantibodies to the antigen myeloperoxidase in human serum.

4. Intended Use of Device

An enzyme-linked immunosorbent assay (ELISA) designed for the detection and measurement of autoantibodies to the antigen myeloperoxidase in human serum. The test is intended as an aid in the diagnosis of current or past autoimmune mediated vasculitides.

5.(A) Technological Characteristics

Proposed Device

The VIRGO ® pANCA Kit is an enzyme-linked immunosorbent assay. The device utilizes optical density as a measure of antibody presence, with an established cutoff between a positive and a negative reaction.

Predicate Device

The Scimedx MPO ANTIBODY EIA is also an enzyme-linked immunosorbent assay. The device utilizes optical density as a measure of antibody presence, with an established cutoff between a positive and a negative reaction.

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5.(B) Performance Data

Precision

To evaluate precision, inter-assay and intra-assay studies were conducted.

A. Inter-assay

Seven samples were assayed in duplicate twice a day for five different days.

Sample	Mean OD	Std. Dev.	% CV	Mean Units	Std. Dev	% CV
1	3.338	0.142	4.2	12.6	0.828	6.6
2	2.333	0.142	6.1	8.6	0.542	6.3
3	1.376	0.111	8.1	5.1	0.370	7.3
4	0.712	0.071	10.0	2.6	0.221	8.4
5	0.362	0.040	11.0	1.4	0.162	11.7
6	0.047	0.005	N/A	0.2	0.015	N/A
7	0.038	0.006	N/A	0.1	0.023	N/A

The assay Cutoff Serum, and Positive Control were assayed concurrently twice a day for each of the five days.

	Mean OD	Std. Dev.	% CV
Cutoff Serum	0.271	0.027	10.1
Positive Control	4.027	0.096	2.4

B. Intra-assay

The same seven serum samples were assayed 20 consecutive times in a single run.

Sample	Mean OD	Std. Dev.	% CV
1	3.274	0.131	4.0
2	2.239	0.121	5.4
3	1.315	0.112	8.5
4	0.570	0.034	5.9
5	0.374	0.024	6.5
6	0.066	0.003	4.3
7	0.058	0.004	7.1

The assay Cutoff Serum, and Positive Control were assayed concurrently 20 consecutive times in a single run

	Mean OD	Std. Dev.	% CV
Cutoff Serum	0.264	0.017	6.4
Positive Control	3.895	0.166	4.3

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Comparison Testing

A total of 132 serum specimens (22 pANCA positive specimens taken from throughout the United States, 40 specimens from individuals demonstrating pauci-immune necrotizing and/or crescentic glomerulonephritis, and, 70 specimens from normal apparently healthy donors} were concurrently assayed by both the predicate device and the proposed device. The results are presented in the tables that follow:

Table 1.1 pANCA Panel 1. n = 22Predicate Device
Proposed Device	Positive	Negative	Total
Positive	21	0	21
Negative	0	1	1
Total	21	1	22

Relative Sensitivity = 100.0 % {21/21}, 0.85 confidence interval = 84.5 % to 100 %

Table 1.2 pANCA Panel 2. n = 40Predicate Device
Proposed Device	Positive	Negative	Total
Positive	40	0	40
Negative	0	0	0
Total	40	0	40

Relative Sensitivity = 100.0 % {40/40}. 0.88 confidence interval = 91.2 % to 100 %

Table 1.3 Normals, n = 70Predicate Device
Proposed Device	Positive	Negative	Total
Positive	0	0	0
Negative	81	62	70
Total	8	62	70

Relative Specificity = 100 % {62/62}, 4.8 confidence interval = 94.2 % to 100 %

The eight discrepant samples were assayed with a third party IFA kit and were found to be negative.

The range of AU values for the positive specimens was 1.2 to 18. The average AU value for the normal specimens was 0.3 with a range of 0.1 to 0.8

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Interfering Substances

Libemic, icteric, and hemolytic samples were evaluated with the assay following NCCLS Document EP7-P Proposed Guideline, Interference Testing in Clinical Chemistry. The results indicate that there is no significant effect (<15 % variation) on the assay for samples with:

Hemoglobin concentration: Bilirubin concentration: Lipid concentration:

≤ 500 mg/dL < 20 maldL ≤ 3000 ma/dL

Prozone

The VIRGO ® pANCA Kit was used to assay several high titered serum samples to determine if the kit would return unexpectedly low values. The results of this evaluation indicate that the kit gives appropriately high positive results with high titered sera.

Conclusions

The results of the comparative studies support the claim that the proposed device is substantially equivalent to the predicate device and performs as an effective screening assay.

510(k) Summary Page 5

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Image /page/5/Picture/1 description: The image is a black and white logo for the U.S. Department of Health and Human Services. The logo features a stylized abstract design resembling a bird or a wing. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular pattern around the design.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

NOV 1 3 1997

Mr. Joseph M. Califano Manager, Requlatory Affairs Hemagen Diagnostics, Inc. 34-40 Bear Hill Road Waltham, Massachusetts 02154

Re : K973824 Trade Name: VIRGO® pANCA Kit (EIA method) Tier: II Regulatory Class: II Product Code: мов Dated: September 30, 1997 Received: October 7, 1997

Dear Mr. Califano:

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 A substantially equivalent determination assumes compliance to 895. 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 (QS) inspections, the Food and Drug Administration (FDA) will verify such Failure to comply with the GMP regulation may result in assumptions. 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) Additionally, for questions on the promotion and 594-4588. 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 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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K973824

Device Name:

VIRGO ® pANCA Kit

Indication(s) For Use

(PLEASE DO NOT WRITE BELOW THIS LINE)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Peter E. Mater

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

Prescription Use
(Fer 21 CFR 801.109)

Over-The-Counter-Use

Regulation Number and Section

§ 866.5660 Multiple autoantibodies immunological test system.

(a)
Identification. A multiple autoantibodies immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the autoantibodies (antibodies produced against the body's own tissues) in serum and other body fluids. Measurement of multiple autoantibodies aids in the diagnosis of autoimmune disorders (disease produced when the body's own tissues are injured by autoantibodies).(b)
Classification. Class II (performance standards).