The LEUKO EZ VUE™ test is an immunochromatographic test for the qualitative detection of elevated levels of fecal lactoferrin, a marker for fecal leukocytes and an indicator of intestinal inflammation. The LEUKO EZ VUE™ test detects lactoferrin in liquid, semi-solid, and solid fecal specimens. A positive test result indicates an increased level of fecal lactoferrin and warrants additional testing. FOR IN VITRO DIAGNOSTIC USE.

Device Description

The LEUKO EZ VUE™ test is a 10 minute immunochromatographic device for the detection of elevated levels of lactoferrin, a marker for fecal leukocytes and an indicator of intestinal inflammation. The test utilizes the same polyclonal antibodies against human lactoferrin as our previously cleared LEUKO-TEST assay. The polyclonal antibodies to human lactoferrin are immobilized on nitrocellulose and the conjugate consists of the same antibodies linked to colloidal gold particles. The membrane cassette contains two stripes of immobilized antibodies. One stripe contains anti-lactoferrin antibodies. The other, representing a control stripe, contains anti-IgG antibodies. The diluted sample and gold conjugate migrate by capillary action when the sample is added to the well. If elevated lactoferrin is present in the sample, gold conjugate-lactoferrin complexes form and are captured by the immobilized anti-lactoferrin antibodies in the stripe. The lactoferrin-conjugate-antibody complexes appear as a single red line in the test portion of the Results window. In the control stripe, conjugate binds to the immobilized anti-IgG antibodies, demonstrating correct migration of the sample and conjugate along the membrane. The conjugate-anti-IgG antibodies appear as a single red line in the control portion of the Results window.

AI/ML Overview

Here's a summary of the acceptance criteria and study details for the LEUKO EZ VUE™ device, based on the provided 510(k) summary:

Acceptance Criteria and Device Performance

The acceptance criteria for the LEUKO EZ VUE™ were based on its agreement with the predicate device, LEUKO-TEST.

Acceptance Criteria	Reported Device Performance (%)	95% Confidence Intervals
Percent Positive Agreement with LEUKO-TEST	93%	86 – 97%
Percent Negative Agreement with LEUKO-TEST	80%	74 – 84%
Overall Percent Agreement with LEUKO-TEST	83%	80 – 86%

Study Information

This study evaluated the performance of the LEUKO EZ VUE™ test against the predicate LEUKO-TEST in clinical studies.

Sample size used for the test set and the data provenance:
- Sample Size: 375 specimens
- Data Provenance: The document does not specify the country of origin. It indicates "clinical studies" without further detail on the nature (retrospective or prospective) of the data collection for these specific comparative studies.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The "ground truth" for this study was established using the results of the LEUKO-TEST (K931241/A1), which is a previously cleared latex agglutination test. The document does not mention the use of experts to establish a separate ground truth or to interpret the LEUKO-TEST results for the purpose of this comparative study.
Adjudication method for the test set:
- Not applicable. The study compares the LEUKO EZ VUE™ to the LEUKO-TEST directly, rather than against an expert-adjudicated ground truth.
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, an MRMC comparative effectiveness study was not done. This device is a rapid in-vitro diagnostic test, not an AI-assisted diagnostic tool requiring human interpretation. The output is a visual presence of a red line.
If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, the LEUKO EZ VUE™ test's performance was evaluated as a standalone device by comparing its results directly to the LEUKO-TEST results. It is an immunochromatographic device that provides a visual reading ("red line in the test portion of the Results window").
The type of ground truth used:
- The ground truth for comparison was the results obtained from the LEUKO-TEST (K931241/A1).
The sample size for the training set:
- The document does not explicitly mention a "training set" or its size. As this is a performance comparison of an in-vitro diagnostic device against a predicate, typical machine learning training set paradigms are not directly applicable in the same way. The study focuses on evaluating the device's performance on a set of clinical samples.
How the ground truth for the training set was established:
- Not applicable, as a distinct "training set" with established ground truth, in the context of machine learning, is not described for this type of IVD performance study. The performance evaluation samples were compared against the results of the predicate LEUKO-TEST.

Summary

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LEUKO EZ VUE™ 510(k)

Image /page/0/Picture/1 description: The image shows a handwritten string of characters. The string appears to be a combination of letters and numbers. The string reads 'K071712'.

7.0 510(k) SUMMARY OF THE LEUKO EZ VUE™

Contact Information	Charles Pennington
	Director of Product Development
	TECHLAB®, Inc.	DEC 0 4 2007
	2001 Kraft Drive
	Corporate Research Center
	Blacksburg, VA 24060-6358
	Phone: 540-953-1664
	FAX: 540-953-1665
	Email: cpennington@techlab.com
Date Prepared	November 19, 2007
	Product and Trade Name TECHLAB® LEUKO EZ VUE™
Classification	Class I, 21 CFR 866.5570

Predicate Devices

TECHLAB® LEUKO-TEST (K931241/A1). The LEUKO-TEST is a latex . agglutination test for detecting elevated levels of fecal lactoferrin as a marker of fecal leukocytes and intestinal inflammation. The test is simple to use and rapid.
Methylene Blue stain and Gram stain along with microscopic observation. . This assay is exempt from 510(k), but serves as a predicate device because it was marketed prior to 1976 and continues to be legally marketed today. The procedure involves the staining of fecal smears from patients with diarrhea followed by microscopic observation for the presence of leukocytes. The analysis must be performed by qualified individuals who have experience in the microscopic identification of leukocytes in fecal specimens. In addition, the test must be performed as soon as possible after collection of the specimen because of the instability of fecal leukocytes.

Intended Use

Device Description

The LEUKO EZ VUE™ test is a 10 minute immunochromatographic device for the detection of elevated levels of lactoferrin, a marker for fecal leukocytes and an indicator

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of intestinal inflammation. The test utilizes the same polyclonal antibodies against human lactoferrin as our previously cleared LEUKO-TEST assay. The polyclonal antibodies to human lactoferrin are immobilized on nitrocellulose and the conjugate consists of the same antibodies linked to colloidal gold particles. The membrane cassette contains two stripes of immobilized antibodies. One stripe contains anti-lactoferrin antibodies. The other, representing a control stripe, contains anti-IgG antibodies. The diluted sample and gold conjugate migrate by capillary action when the sample is added to the well. If elevated lactoferrin is present in the sample, gold conjugate-lactoferrin complexes form and are captured by the immobilized anti-lactoferrin antibodies in the stripe. The lactoferrin-conjugate-antibody complexes appear as a single red line in the test portion of the Results window. In the control stripe, conjugate binds to the immobilized anti-IgG antibodies, demonstrating correct migration of the sample and conjugate along the membrane. The conjugate-anti-IgG antibodies appear as a single red line in the control portion of the Results window.

Test	Description	Format	Turn-around time	Limitations
LEUKO EZVUETM	Intended fordetermining elevatedlevels of fecallactoferrin as amarker for fecalleukocytes and anindicator of intestinalinflammation. Apositive test resultindicates anincreased level offecal lactoferrin andwarrants additionaltesting.	Lateral flow	10minutes	Rapid test formatas the LEUKO-TEST butovercomesinherent problemsof latexagglutination,includingdifficult-to-readreactions
LEUKO-TEST(K931241/A1)	Intended fordeterminingelevated levels offecal lactoferrinas a marker forfecal leukocytesand an indicatorof intestinalinflammation	Latexagglutination	3 minutes	Latexagglutination maygive difficult-to-read reactions aswell as otherinherent problems
Methylene Blueand Gram stainfor observingfecal leukocytes	Intended fordetecting fecalleukocytes infecal smears	Staining of fecalsmears andexamination forleukocytes	30 to 60minutes	Requiresexperience and testmust be performedwithin minutes ofcollecting the fecalspecimen due toinstability ofleukocytes

Comparative information of equivalent devices

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Summary of Performance Data

TECHLAB®, Inc. has evaluated the LEUKO EZ VUE™ test, which is a new lateral flow test for the detection of elevated levels of fecal lactoferrin, a marker for fecal leukocytes and an indicator of intestinal inflammation. The purpose of this study was to evaluate the performance of the LEUKO EZ VUE™ test as an in vitro diagnostic aid to help identify patients with inflammatory diarrhea.

When comparing the LEUKO EZ VUE™ to the LEUKO-TEST in clinical studies, the LEUKO EZ VUE™ test had positive, negative, and overall agreements of 93%, 80%, and 83%, respectively. Individual results are shown in the table below.

LEUKO EZ VUETM vsLEUKO-TEST(N=375)	LEUKO-TESTPositive	LEUKO-TESTNegative	Total
LEUKO EZ VUETMPositive	98	55	153
LEUKO EZ VUETMNegative	7	215	222
Total	105	270	375

		95% Confidence Intervals
Percent Positive Agreement	93%	86 – 97%
Percent Negative Agreement	80%	74 – 84%
Overall Percent Agreement	83%	80 – 86%

Additional studies including intra- and inter-assay variation showed the assay to be reproducible with all positive samples remaining positive and all negative samples remaining negative upon additional testing. Serial dilutions of highly purified human lactoferrin demonstrated acceptable assay sensitivity with a minimum detection limit ≥ 128 ng/mL.

The LEUKO EZ VUE™ test is simple to perform, requiring minimal training. The procedure includes a single specimen dilution, the transfer of 4 drops of diluted specimen to the sample well of the membrane cassette and a visual reading following a 10-minute incubation.

Based on these findings, we believe the LEUKO EZ VUE™ test is substantially equivalent to the LEUKO TEST now used to evaluate patients for elevated fecal leukocytes as an indicator of intestinal inflammation. Further, our results demonstrate that the LEUKO EZ VUE™ test is suitable as an in vitro diagnostic aid to help identify patients with inflammatory diarrhea.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/3/Picture/1 description: The image shows the logo for the Department of Health & Human Services (HHS). The logo consists of a stylized depiction of an eagle or bird in flight, composed of three curved lines that suggest feathers or wings. The bird is positioned within a circular border, and the text "DEPARTMENT OF HEALTH & HUMAN SERVICES (USA)" is arranged around the upper half of the circle.

Public Health Service

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

DEC 0 4 2007

TECHLAB Inc. c/o Mr. Charles Pennington Director of Product Development 2001 Kraft Drive Blacksburg, VA 24060-6358

Re: K071712

Trade/Device Name: TECHLAB® LEUKO EZ VUETM Regulation Number: 21 CFR 866.5570 Regulation Name: Lactoferrin, antigen, antiserum, control Regulatory Class: Class I Product Code: DEG Dated: November 19, 2007 Received: November 21, 2007

Dear Mr. Pennington:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). 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 (PMA), 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 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820). This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The

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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 information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (240) 276-0450. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding postmarket surveillance, please contact CDRH's Office of Surveillance and Biometric's (OSB's) Division of Postmarket Surveillance at 240-276-3474. For questions regarding the reporting of device adverse events (Medical Device Reporting (MDR)), please contact the Division of Surveillance Systems at 240-276-3464. You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (240) 276-3150 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely vours.

Robert Becker

Robert L. Becker, Jr., M.D., Ph Director Division of Immunology and Hematology Devices Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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2.0 STATEMENT OF INTENDED USE

Indications for Use

510(k) Number (if known): KO71712

Device Name: LEUKO EZ VUE™

Prescription Use X (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use (21 CFR 807 Subpart C)

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

Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)

m Chan

Division Sign-Off

Office of In Vitro Diagnostic Device Evaluation and Safety

510(k) K071712

Regulation Number and Section

§ 866.5570 Lactoferrin immunological test system.

(a)
Identification. A lactoferrin immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the lactoferrin (an iron-binding protein with the ability to inhibit the growth of bacteria) in serum, breast milk, other body fluids, and tissues. Measurement of lactoferrin may aid in the diagnosis of an inherited deficiency of this protein.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.