IMMULITE 2000 Folic Acid is for in vitro diagnostic use with the IMMULITE 2000 Analyzer – for the quantitative measurement of folic acid in serum, heparinized plasma or ascorbic acid-treated whole blood, as an aid in clinical diagnosis and treatment of anemia.

Device Description

IMMULITE® 2000 Folic Acid is a clinical device for use with the IMMULITE® 2000 Automated Immunoassay Analyzer. IMMULITE 2000 Folic Acid is a chemiluminescent immunoassay. The assay begins with a 2-cycle, on-board sample treatment of patient serum, plasma or ascorbic acid-treated whole blood. The sample, along with ligand-labeled folic acid, is first treated with dithiothreitol (DTT), in a reaction tube containing no bead, and then with sodium hydroxide/potassium cyanide (NaOH/KCN), in a second treatment cycle. The treated sample is transferred to a second reaction tube containing a murine anti-folate binding protein antibody-coated polystyrene bead and folate binding protein (FBP). During a 30-minute incubation, folic acid released from binding proteins in the patient sample competes with ligand-labeled folic acid for binding with FBP. The bead is washed and alkaline phosphatase labeled anti-ligand is added. During the final 30-minute incubation, the alkaline phosphatase anti-ligand binds to the ligand-labeled folate that was bound to the bead during the first incubation. The unbound enzyme conjugate is removed by centrifugal wash. Substrate is then added. The chemiluminescent substrate, a phosphate ester of adamantyl dioxetane, is then added and the test unit is incubated for a further 10 minutes. The chemiluminescent substrate undergoes hydrolysis in the presence of alkaline phosphatase to yield an unstable intermediate. Production of this intermediate results in a sustained emission of light. The bound complex - and thus also the photon output - is inversely proportional to the concentration of folic acid in the sample.

AI/ML Overview

Here's an analysis of the provided text, focusing on acceptance criteria and the study that demonstrates the device meets them:

Acceptance Criteria and Device Performance

The provided document describes a 510(k) submission for the IMMULITE® 2000 Folic Acid device. The study performed is a method comparison against a legally marketed predicate device (DPC's IMMULITE® Folic Acid). In such a comparison, the acceptance criteria are generally established to demonstrate substantial equivalence, meaning the new device performs similarly enough to the predicate that it can be considered safe and effective for its intended use.

While explicit "acceptance criteria" are not listed as numerical thresholds in this summary, the reported device performance in the method comparison study provides the evidence for acceptance. The primary metric for showing equivalence in this context is the linear regression analysis and the correlation coefficient (r). A high correlation coefficient (close to 1) indicates that the two methods produce very similar results across the range of concentrations tested.

Here's a table summarizing the implicit acceptance criteria based on standard practice for method comparisons and the reported performance:

Acceptance Criterion (Implicit for Method Comparison)	Reported Device Performance (IMMULITE® 2000 vs. IMMULITE® Predicate)
High correlation (r-value close to 1) indicating strong agreement between methods.	Serum: r = 0.996 Hemolysates: r = 0.981
Slope of linear regression close to 1 indicating similar relative measurement between methods.	Serum: Slope = 0.96 Hemolysates: Slope = 1.18
Y-intercept of linear regression close to 0 indicating similar absolute measurement between methods (minimal bias).	Serum: Y-intercept = -0.54 ng/mL Hemolysates: Y-intercept = -29 ng/mL
Similar mean values between the two methods over the tested concentration range.	Serum: IMMULITE® 2000 Mean: 8.3 ng/mL IMMULITE® Predicate Mean: 9.2 ng/mL Hemolysates: IMMULITE® 2000 Mean: 128 ng/mL IMMULITE® Predicate Mean: 134 ng/mL
Concentration range of samples tested adequately covers the clinically relevant range.	Serum: 1.8 to 20 ng/mL Hemolysates: 46 to 260 ng/mL

The "Conclusion" section explicitly states: "The data presented in this summary of safety and effectiveness is the data the Food and Drug Administration used in granting DPC substantial equivalence for IMMULITE® 2000 Folic Acid." This confirms that the reported performance met the FDA's implicit acceptance criteria for substantial equivalence.

Study Details

Here's a breakdown of the specific information requested about the study:

A table of acceptance criteria and the reported device performance: (Provided above)
Sample size used for the test set and the data provenance:
- Serum test set: 156 samples
- Hemolysates test set: 49 samples
- Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. However, given it's a regulatory submission for a clinical diagnostic device, it is typically expected that the data would be from a relevant clinical population and likely collected prospectively or from a well-characterized retrospective bank. The submission date (Oct 26, 1999) suggests it would be from that era's standard clinical testing.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This is not applicable as the "ground truth" for this type of device (quantitative immunoassay) is not established by human experts in the same way as, for example, image interpretation. The ground truth is the measurement provided by the predicate device, which is presumed to be accurate and reliable.
Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not applicable. Adjudication methods are typically used in studies involving subjective interpretation (e.g., radiology reads) where multiple experts might disagree. In this case, the reference method (predicate device) provides the "reference standard."
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 study is a technical method comparison between two automated immunoassay devices, not an assessment of human reader performance, with or without AI assistance.
If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, this was a standalone study of the IMMULITE® 2000 Folic Acid analyzer. The device performs the quantitative measurement of folic acid in patient samples without direct human intervention in the measurement process itself, beyond sample loading and results interpretation. The study evaluates the algorithm's (device's) performance against a predicate device.
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The "ground truth" or reference standard for this method comparison study was the measurements obtained from the legally marketed predicate device, DPC's IMMULITE® Folic Acid.
The sample size for the training set:
- The document does not explicitly mention a "training set" in the context of machine learning or AI. For a traditional immunoassay device, the development process would involve internal validation and optimization, but not typically a "training set" as understood in current AI contexts. The sample sizes mentioned (156 serum, 49 hemolysates) are for the pivotal performance evaluation (test set) against the predicate.
How the ground truth for the training set was established:
- Not applicable, as a "training set" in the AI sense is not described. The device's underlying principles are based on established immunoassay chemistry and detection, with the predicate device serving as the reference for performance validation.

Summary

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K993254

Nov 1 2 1999

510(k) Summary of Safety and Effectiveness

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

Name:	Diagnostic Products Corporation
Address:	5700 West 96th StreetLos Angeles, California 90045-5597
Telephone Number:Facsimile Number:	(310) 645-8200(310) 645-9999
Contact Person:	Edward M. Levine, Ph.D.Director of Clinical Affairs
Date of Preparation:	October 26, 1999
Device Name:	IMMULITE® 2000 Folic Acid
Trade:	Reagent system for the determination of folic acidin serum, heparinized plasma, or whole blood.
Catalog Number:	L2KFO2 (200 tests); L2KFO6 (600 tests)
Classification:	Class II device (862.1295, 75CGN)
Manufacturer:	Diagnostic Products Corporation5700 West 96th StreetLos Angeles, California 90045-5597
Establishment Registration #:	DPC's Registration # is 2017183
Substantially EquivalentPredicate Device:	DPC's IMMULITE® Folic Acid (K943705)
Description of Device:	IMMULITE® 2000 Folic Acid is a clinical devicefor use with the IMMULITE® 2000 AutomatedImmunoassay Analyzer

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Intended Use of the Device:

IMMULITE 2000 Folic Acid is for in vitro diagnostic use with the IMMULITE 2000 Analyzer - for the quantitative measurement of folic acid in serum, heparinized plasma or ascorbic acid-treated whole blood, as an aid in clinical diagnosis and treatment of anemia.

Summary and Explanation of the Test:

Folic acid (folate) and vitamin B12 are nutrients essential to hematopoiesis. Megaloblastic anemia is almost always due to lack of one of these two vitamins. Circulating folate levels are usually normal or elevated in vitamin B12 deficiency, but red cell folate levels are frequently low in this condition.

Folate deficiency is commonly encountered as a result of dietary deficiency (as in alcoholism) or increased demand for this vitamin (as in pregnancy). Unlike vitamin B12, folate is a heat-labile vitamin susceptible to loss by prolonged cooking. Accordingly, the prevalence of folate deficiency exhibits major demographic variations, apparently reflecting differences in-dietary and culinary habits.

Circulating folate levels, being strongly influenced by recent intake, are unreliable as an index to tissue stores. Thus, folate levels measured in serum or plasma may be normal in the face of folate deficiency. Conversely, circulating levels may be low long before tissue stores have been exhausted. Accordingly, it is important to measure red cell folate levels whenever serum or plasma levels are measured.

Performance Equivalence - Technology Comparison:

IMMULITE® and IMMULITE® 2000 Folic Acid are chemiluminescent immunoassays. The technology in DPC's IMMULITE® 2000 Folic Acid is a unique combination of technologies employed in previously cleared and commercially marketed DPC products.

The IMMULITE 2000 Folic Acid assay begins with a 2-cycle, on-board sample treatment of patient serum, plasma or ascorbic acid-treated whole blood (for measuring red cell folate). The sample, along with ligand-labeled folic acid, is first treated with dithiothreitol (DTT), in a reaction tube containing no bead, and then with sodium hydroxide/potassium cyanide (NaOH/KCN), in a second treatment cycle. The treated sample is transferred to a second reaction tube containing a murine anti-folate binding protein antibody-coated polystyrene bead and folate binding protein (FBP). During a 30-minute incubation, folic acid released from binding proteins in the patient sample competes with ligand-labeled folic acid for binding with FBP. The bead is washed and alkaline phosphatase labeled anti-ligand is added. During the final 30-minute incubation, the alkaline phosphatase anti-ligand binds to the ligand-labeled folate that was bound to the bead during the first incubation. The unbound enzyme conjugate is removed by centrifugal wash. Substrate is then added.

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Technology Comparison (continued):

The chemiluminescent substrate, a phosphate ester of adamantyl dioxetane, is then added and the test unit is incubated for a further 10 minutes. The chemiluminescent substrate undergoes hydrolysis in the presence of alkaline phosphatase to vield an unstable intermediate. Production of this intermediate results in a sustained emission of light. The bound complex - and thus also the photon output - is inversely proportional to the concentration of folic acid in the sample.

IMMULITE® Folic Acid is a boil, competitive, ligand-labeled, protein binding chemiluminescent assay with in situ immobilization, and with an anti-ligand detection system. The solid phase, a polystyrene bead enclosed within an IMMULITE Test Unit, is coated with a murine monoclonal antibody specific for folic acid binding protein. The sample is pretreated by boiling in the presence of dithiothreitol to denature endogenous binding proteins to release folic acid. The treated patient sample, ligand-labeled folic acid analog and folic acid binding protein are simultaneously introduced into the Test Unit, and incubated for approximately 30 minutes at 37 °C with intermittent agitation. During this time, folic acid in the sample competes with the ligand-labeled folic acid analog for a limited amount of folic acid binding protein, and the folic acid binding protein is captured by the antibody on the bead. Unbound analog is then removed by a centrifugal wash, after which an alkaline phosphatase-anti-ligand conjugate is introduced and the test unit is incubated for an additional 30 minute cvcle. The unbound enzyme conjugate is removed by a centrifugal wash.

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Method Comparison

Serum

The IMMULITE® 2000 Folic Acid procedure was compared to DPC's IMMULITE® Folic Acid on 156 serum samples, with folic acid concentrations ranging from 1.8 to 20 ng/mL.

8.3 ng/mL (IMMULITE® 2000) Means: 9.2 ng/mL (IMMULITE®)

Linear regression analysis of folic acid values yielded the following statistics:

(IMMULITE® 2000) = 0.96 (IMMULITE®) - 0.54 ng/mL r = 0.996

Hemolysates

The IMMULITE® 2000 Folic Acid procedure was also compared to DPC's IMMULITE® Folic Acid on 49 samples, with folic acid concentrations ranging from 46 to 260 ng/mL.

Means:	128 ng/mL (IMMULITE® 2000 Folic Acid)
	134 ng/mL (IMMULITE® Folic Acid)

Linear regression analysis of folic acid values yielded the following statistics:

(IMMULITE® 2000) = 1.18 (IMMULITE®) - 29 ng/mL r = 0.981

Conclusion:

The data presented in this summary of safety and effectiveness is the data the Food and Drug Administration used in granting DPC substantial equivalence for IMMULITE® 2000 Folic Acid.

Edward A. Fessier

Edward M. Levine, Ph.D Director of Clinical Affairs

10/26/89

Date

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Image /page/4/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circle with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is a stylized symbol that resembles a human figure in profile, with three overlapping heads or faces.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

NOV 1 2 1999

Edward M. Levine, Ph.D. Director of Clinical Affairs Diagnostic Products Corporation 5700 West 96th Street Los Angeles, California 90045-5597

Re: K993254 Trade Name: Immulite® 2000 Folic Acid Regulatory Class: II Product Code: CGN Dated: September 24, 1999 Received: September 28, 1999

Dear Dr. Levine:

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 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). 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 requirements, as set forth in the Quality System Regulation (OS) 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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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 (301) 443-6597, or at its internet address "http://www.fda.gov/cdrh/dsma/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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510(k) Number (if known): Device Name: IMMULITE® 2000 Folic Acid

Indications For Use:

Cooper
(Division Sign-Off)
Division of Clinical Laboratory Devices
510(k) Number K993254

(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)

Over-The-Counter Use

(Optional Format 1-2-96)

Regulation Number and Section

§ 862.1295 Folic acid test system.

(a)
Identification. A folic acid test system is a device intended to measure the vitamin folic acid in plasma and serum. Folic acid measurements are used in the diagnosis and treatment of megaloblastic anemia, which is characterized by the presence of megaloblasts (an abnormal red blood cell series) in the bone marrow.(b)
Classification. Class II.