The C4 assay is used for the quantitation of C4 in human serum or plasma. Complement is a group of serum proteins which destroy infectious agents. Measurement of these proteins aids in the diagnosis of immunologic disorders, especially those associated with deficiencies of complement components.

Device Description

C4 is an in vitro diagnostic assay for the quantitative determination of C4 in human serum or plasma. Antigen in the sample bonds to the specific antibody in the reagent, forming an immune complex. The immune complex causes an increase in light scattering, measured by reading turbidity at 604 nm, which correlates with the concentration of C4 in the sample.

AI/ML Overview

Here's an analysis of the provided text regarding the C4 assay's acceptance criteria and the study proving its performance:

Considering the nature of the device (an in vitro diagnostic assay for quantitative C4 determination), some of the requested information (like multi-reader multi-case studies, ground truth established by experts like radiologists, or pathology) are not directly applicable to this type of medical device. The focus for IVD assays is typically on analytical performance characteristics and comparison to a predicate device.

Acceptance Criteria and Reported Device Performance

Acceptance Criteria	Reported Device Performance	Comments
Correlation with Predicate Device (K-ASSAY C4 assay on Hitachi 717 Analyzer)		Aim to demonstrate substantial equivalence.
Correlation Coefficient (r)	0.9956	Considered excellent, indicating a strong linear relationship.
Slope	1.003	Close to 1, indicating similar rate of change.
Y-intercept	0.018 mg/dL	Close to 0, indicating minimal constant bias.
Precision (Total %CV using two levels of control material)		A measure of reproducibility and repeatability. Lower %CV indicates better precision.
Level 1 / Panel 401	1.6%	Excellent precision for diagnostic assays.
Level 2 / Panel 402	2.5%	Excellent precision for diagnostic assays.
Assay Range	up to 82.23 mg/dL	Defines the concentrations the assay can accurately measure. Specific acceptance range not explicitly stated, but the reported range is a characteristic.
Limit of Quantitation (Sensitivity)	0.471 mg/dL	The lowest concentration the assay can reliably measure. Specific acceptance limit not explicitly stated, but the reported value is a characteristic.

Study Details

Sample Size Used for the Test Set and Data Provenance:
- The document states "Comparative performance studies were conducted." However, the exact sample size for the method comparison or precision studies (e.g., number of patient samples, number of replicates) is not explicitly mentioned in the provided summary.
- Data Provenance: Not specified (e.g., country of origin, retrospective or prospective). Given the nature of a 510(k) submission for an in vitro diagnostic, it's highly likely to be prospective clinical laboratory testing.
Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:
- Not applicable in the traditional sense for this type of in vitro diagnostic device. "Ground truth" for an IVD assay's analytical performance is typically established by:
  - Reference Methods: The predicate device itself (K-ASSAY C4 assay on Hitachi 717 Analyzer) serves as the "reference standard" against which the new device's performance is compared.
  - Control Materials: Certified or well-characterized control materials are used for precision studies.
  - Standard Analytical Procedures: Following established laboratory protocols for performing the tests.
- There isn't a need for a panel of "experts" (like radiologists interpreting images) to establish ground truth for quantitative biochemical measurements in this context.
Adjudication Method for the Test Set:
- Not applicable. Adjudication methods (like 2+1, 3+1) are typically used for subjective assessments (e.g., image interpretation) where multiple human readers disagree. For quantitative assays comparing numerical results, statistical methods like correlation coefficients, slope, and intercept are used for comparison, and precision is measured directly.
Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No. This type of study is primarily relevant for imaging devices or other diagnostic tools where human interpretation plays a significant role and the benefit of AI assistance for human readers can be quantified. The C4 assay is an automated in vitro diagnostic test, so there is no "human reader" in the loop for interpretation in the same way.
Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study:
- Yes, effectively. The reported performance characteristics (correlation, precision, assay range, sensitivity) are inherently "standalone" as they describe the analytical performance of the C4 assay system (reagents and AEROSET™ Analyzer) without human interpretive input. The C4 assay is the algorithm/device under evaluation.
Type of Ground Truth Used:
- For the method comparison, the "ground truth" was established by the results obtained from the legally marketed predicate device (K-ASSAY C4 assay on the Hitachi 717 Analyzer). This is a common form of "truth" for demonstrating substantial equivalence for new IVD devices.
- For precision, the ground truth involves the known values of the control materials and the statistical calculation of variability from repeated measurements.
Sample Size for the Training Set:
- Not applicable/Not mentioned. This device is an in vitro diagnostic assay, not an AI/Machine Learning algorithm that undergoes a "training phase" in the traditional sense. The development of such assays involves reagent formulation, instrument calibration, and optimization based on chemical and analytical principles, not on "training data" for a learning algorithm.
How the Ground Truth for the Training Set Was Established:
- Not applicable for the reasons stated above. There isn't a "training set" with established ground truth in the context of this chemical assay.

Summary

{0}------------------------------------------------

K983356

510(k) Summary

Submitter's Name/Address

Abbott Laboratories 1920 Hurd Drive Irving, Texas 75038 Contact Person Linda Morris Senior Regulatory Specialist MS 1-8 Regulatory Affairs (972) 518-6711 Fax (972) 753-3367

Date of Preparation of this Summary:	September 23, 1998
Device Trade or Proprietary Name:	C4
Device Common/Usual Name or Classification Name:	Complement 4
Classification Number/Class:	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: { 983335 0 .

Test Description:

Substantial Equivalence:

The C4 assay is substantially equivalent to the K-ASSAY C4 assay (K964297/S3) on the Hitachi® 717 Analyzer.

C4 510(k) September 23, 1998 C4 5 vl

Section II Page 1

Image /page/0/Picture/15 description: The image shows a sequence of numbers. The numbers are 000011. The numbers are in a bold, sans-serif font. The image is black and white.

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

Both assays vield similar Performance Characteristics.

Similarities:

Both assays are in vitro immunoassay methods. •
Both assays can be used for the quantitative determination of C4. .
Both assays vield similar clinical results. .
Both assays are based on the light scattering properties of antigen-antibody . complexes.

Differences:

There is a difference between the assay range. .

Intended Use:

The C4 assay is used for the quantitation of C4 in human serum or plasma.

Performance Characteristics:

Comparative performance studies were conducted using the AEROSET™ System. The C4 assay method comparison vielded acceptable correlation with the K-ASSAY C4 assay on the Hitachi 717 Analyzer. The correlation coefficient = 0.9956, slope = 1.003, and Y-intercept = 0.018 mg/dL. Precision studies were conducted using the C4 assay. Within-run, between-run, and between-day studies were performed using two levels of control material. The total %CV for Level 1/Panel 401 is 1.6% and Level 2/Panel 402 is 2.5%. The C4 assay range is up to 82.23 mg/dL. The limit of quantitation (sensitivity) for the C4 assay is 0.471 mg/dL. These data demonstrate that the performance of the C4 assay is substantially equivalent to the performance of the K-ASSAY C4 assay on the Hitachi 717 Analyzer.

Section II Page 2

Image /page/1/Picture/14 description: The image shows the number 0000012. The number is written in a bold, sans-serif font. The number is black and the background is white. There are six zeros followed by a one and a two.

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

Conclusion:

The C4 assay is substantially equivalent to the K-ASSAY C4 assay on the Hitachi 717 Analyzer as demonstrated by results obtained in the studies.

C4 510(k) September 23, 1998
C4_s_v1 Section II Page 3

Image /page/2/Picture/4 description: The image shows the number 0000013 in a bold, sans-serif font. The numbers are all the same size and are evenly spaced. The number is black and the background is white. The number is likely a serial number or some other type of identification number.

{3}------------------------------------------------

Public Health Service

Image /page/3/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" arranged around the perimeter. Inside the circle is a stylized graphic of three human profiles facing to the right, stacked one above the other.

NOV 4 1998

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Ms. Linda Morris Senior Requlatory Specialist MS 1-8 Requlatory Affairs Abbott Laboratories 1920 Hurd Drive Irvinq, Texas 75038

Re: K983356 Trade Name: ্রের Requlatory Class: II Product Code: DBI Dated: September 23, 1998 Received: September 24, 1998

Dear Ms. Morris:

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 qeneral controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions aqainst 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. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, 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 regulation may result in requlatory 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.

{4}------------------------------------------------

Page 2

This letter will allow you to beqin 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/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

{5}------------------------------------------------

510(k) Number (if known):

C4 Device Name:

Indications For Use:

Peter E. Mahon

(Division Sign-Off)
Division of Clinical Laboratory Devices 1983356
510(k) Number

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

______________________________________________________________________________________________________________________________________________________________________________ Concurrence of CDRH, Office of Device Evaluation (ODE) Prescription Use v Over-The-Counter Use OR (Per 21 CFR 801.109)

(Optional Format 1-2-96)

Regulation Number and Section

§ 866.5240 Complement components immunological test system.

(a)
Identification. A complement components immunological test system is a device that consists of the reagents used to measure by immunochemical techniques complement components C1q , C1r , C1s , C2 , C3 , C4 , C5 , C6 , C7 , C8 , and C9 , in serum, other body fluids, and tissues. Complement is a group of serum proteins which destroy infectious agents. Measurements of these proteins aids in the diagnosis of immunologic disorders, especially those associated with deficiencies of complement components.(b)
Classification. Class II (performance standards).