The LD-1 assay is used for the quantitation of LD-1 (one of a group of enzymes with similar biological activity) in serum. Measurement of LD-1 is used in the diagnosis and treatment of cardiac diseases, such as myocardial infarction.

Device Description

LD-1 is an in vitro diagnostic assay for the quantitative determination of LD-1 in serum. The LD-1 assay is a clinical chemistry assay and employs sodium perchlorate, a chaotropic agent to selectively denature the LDH isoenzyme teteramers with one or more "M" subunits, removing their enzymatic activity. LD-1 is resistant to this denaturation and is assayed simultaneously. The method for measurement of the LDH activity employs the conversion of lactate to pyruvate by LD-1 with a concomitant reduction of NAD to NADH. The rate of NADH formation, as measured by the rate of absorbance increase at 340 nm, is directly proportional to LD-1 activity in the sample.

AI/ML Overview

The provided document describes the LD-1 assay, an in vitro diagnostic assay for the quantitative determination of LD-1 in serum. The study aims to demonstrate substantial equivalence to a predicate device, not necessarily to establish de novo performance against a defined acceptance criterion for a novel device.

Here's an analysis of the provided information, framed within your requested structure:

Acceptance Criteria and Study to Prove Device Meets Acceptance Criteria

The LD-1 assay's acceptance criteria and proven performance are established through a substantial equivalence comparison to a predicate device, the Roche® Cobas Mira® Plus Automated Chemistry System LD-1 assay (K894081). The study demonstrates that the LD-1 assay yields similar performance characteristics to the predicate.

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria (Implied by Substantial Equivalence to Predicate)	Reported LD-1 Assay Performance	Remarks
Correlation Coefficient with Roche Cobas Mira Plus LD-1: ≥ [Not specified, but generally very high for equivalence]	0.9894	Indicates excellent correlation with the predicate device.
Slope of Method Comparison Regression: ≈ 1.0 (for equivalent results)	1.025	Very close to 1.0, suggesting proportional agreement.
Y-intercept of Method Comparison Regression: ≈ 0 U/L (for equivalent results)	-13.090 U/L	A non-zero intercept suggests a constant difference, though its clinical significance and acceptable range are not specified.
Total %CV for Level 1 Control: ≤ [Not specified]	6.4%	Acceptable precision for a clinical chemistry assay, but no specific threshold mentioned.
Total %CV for Level 2 Control: ≤ [Not specified]	2.8%	Also indicates good precision, but no specific threshold mentioned.
Linearity: Up to predicate's range or clinically relevant range	Up to 480 U/L	Implies that the assay performs reliably within this range.
Limit of Quantitation (Sensitivity): Equivalent to predicate or clinically relevant	10 U/L	Corresponds to the lowest measurable concentration with acceptable accuracy.

Note: The acceptance criteria are implied by the declaration of substantial equivalence to the Roche Cobas Mira Plus LD-1 assay. Specific numerical thresholds for "acceptance" beyond the reported values themselves are not explicitly detailed in the summary. The core "acceptance" is the FDA's agreement that the performance characteristics are sufficiently similar to the legally marketed predicate.

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

Sample Size: The document does not specify the exact sample size for the comparative performance studies (method comparison and precision studies). It only states that "Comparative performance studies were conducted."
Data Provenance: The data provenance (country of origin, retrospective/prospective) is not explicitly stated. However, given it is a 510(k) submission in the US, it is generally assumed that the studies were conducted by or for Abbott Laboratories, a US-based company, and the data would likely be prospective clinical samples or laboratory-generated samples for method performance evaluation.

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

This section is not applicable as the device is a quantitative in vitro diagnostic assay for measuring LD-1 levels. The "ground truth" for such assays is typically established by comparing the device's results to a legally marketed predicate device (as done here) or a reference method/material, rather than expert consensus on individual cases. No experts were involved in establishing "ground truth" for the test set in the traditional sense of medical image interpretation or clinical diagnosis.

4. Adjudication Method for the Test Set

This section is not applicable for a quantitative in vitro diagnostic assay. Adjudication methods (like 2+1, 3+1) are typically used in studies where human readers interpret data (e.g., medical images) and their interpretations need to be reconciled to establish a consensus ground truth. For this type of device, the "ground truth" is the result from the predicate device or a reference method.

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

This section is not applicable. The device is an in vitro diagnostic assay, not an AI-powered diagnostic tool requiring human interpretation or assistance. Therefore, a multi-reader multi-case (MRMC) comparative effectiveness study evaluating human reader performance with or without AI assistance was not conducted.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

The study described is inherently a standalone performance evaluation of the LD-1 assay. As an automated clinical chemistry assay, its performance is assessed directly (correlation, precision, linearity, sensitivity) without human intervention in the result generation or interpretation process of the assay itself. The comparison is algorithm (LD-1 assay) to algorithm (Roche Cobas Mira Plus LD-1 assay).

7. The Type of Ground Truth Used

The "ground truth" used for evaluating the LD-1 assay's performance was the results obtained from the legally marketed predicate device, the Roche Cobas Mira Plus Automated Chemistry System LD-1 assay (K894081). For precision studies, specific control materials with known or expected ranges were used.

8. The Sample Size for the Training Set

This information is not provided and is generally not applicable in the same way it would be for machine learning algorithms. The LD-1 assay is a chemical reaction-based clinical chemistry method. There isn't a "training set" in the sense of data used to train a model. The assay's parameters (reagent concentrations, incubation times, etc.) would be optimized during its development, but this process doesn't typically involve a "training set" with ground truth in the context of a 510(k) submission summary.

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

This section is not applicable for the reasons stated above (see point 8). The assay is based on established chemical principles, not a machine learning model requiring a trained ground truth dataset.

Summary

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K981338

510(k) Summary MAY 1 8 1998

Submitter's Name/Address Abbott Laboratories

1920 Hurd Drive Irving, Texas 75038 Contact Person Mark Littlefield Section Manager MS 1-8 ADD Regulatory Affairs (972) 518-7861 Fax (972) 753-3367

Date of Preparation of this Summary:	April 9, 1998
Device Trade or Proprietary Name:	LD-1
Device Common/Usual Name or Classification Name:	LD-1
Classification Number/Class:	75JGF/Class II

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.

The assigned 510(k) number is:

Test Description:

LD-1 510(k) April 10, 1998 LDIE2.lwp

Section II Page 1

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Substantial Equivalence:

The LD-1 assay is substantially equivalent to the Roche® Cobas Mira® Plus Automated Chemistry System LD-1 assay (K894081) for the serum application. These assays yield similar Performance Characteristics.

Similarities to Roche:

Both assays are in vitro clinical chemistry methods. .
Both assays can be used for the quantitative determination of LD-1 in serum. .
Both assays yield similar clinical results. .

Intended Use:

The LD-1 assay is used for the quantitation of LD-1 in human serum.

Performance Characteristics:

Comparative performance studies were conducted using the ALCYON™ Analyzer. The LD-1 assay method comparison yielded acceptable correlation with the Roche Cobas Mira Plus Automated Chemistry System LD-1. The correlation coefficient = 0.9894, slope = 1.025, and Y-intercept = - 13.090 U/L. Precision studies were conducted using the LD-1 assay. Within-run, between-run, and between-day studies were performed using two levels of control material. The total %CV for Level 1/Panel 111 is 6.4% and Level 2/Panel 112 is 2.8%. The LD-1 assay is linear up to 480 U/L. The limit of quantititation (sensitivity) of the LD-1 assay is 10 U/L. These data demonstrate that the performance of the LD-1 assay is substantially equivalent to the performance of the Roche Cobas Mira Plus Automated Chemistry System LD-1 assay for the serum applications.

D-1 510(k) April 10, 1998 LD1E2 lwo

Section II Page 2

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Conclusion:

The LD-1 assay is substantially equivalent to the Roche Cobas Mira Plus Automated Chemistry System LD-1 assay as demonstrated by results obtained in the studies.

LD-1 510(k) April 10, 1998 LDIE2.lwp

Section II
Page 3

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Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo is circular and contains the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the top half of the circle. In the center of the logo is an abstract symbol that resembles an eagle or a bird in flight, with three human profiles incorporated into the design.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

MAY | 8 |998

Mark Littlefield . Section Manager, Regulatory Affairs Abbott Laboratories 1920 Hurd Drive Irvinq, Texas 75038

Re : K981338 LD-1 Regulatory Class: II Product Code: JGF Dated: April 10, 1998 Received: April 13, 1998

Dear Mr. Littlefield:

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, qood 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 Requlations, Title 21, Parts 800 to 895. ਚ substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set -------------------------------------------------------------------------forth in the Quality System Requlation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Druq 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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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 qeneral 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 (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,
Steven Litman

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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510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________

Device Name:

Indications For Use:

.. . . . . .

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

	Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use ✓	OR	Over-The-Counter Use
(Per 21 CFR 801.109)
	(Optional Format 1-2-96)
	(Division Sign-Off)
	Division of Clinical Laboratory Devices
510(k) Number	n981338

00000000

Regulation Number and Section

§ 862.1445 Lactate dehydrogenase isoenzymes test system.

(a)
Identification. A lactate dehydrogenase isoenzymes test system is a device intended to measure the activity of lactate dehydrogenase isoenzymes (a group of enzymes with similar biological activity) in serum. Measurements of lactate dehydrogenase isoenzymes are used in the diagnosis and treatment of liver diseases, such as viral hepatitis, and myocardial infarction.(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.