This kit has been designed for the measurement of C-reactive protein in human serum and plasma. When used according to instructions, the kit is useful in measuring the acute phase responses in humans to infection, tissue damage and various inflammatory conditions.

Device Description

An enzyme-linked immunosorbent assay (ELISA) designed for the semiquantitative detection of C-Reactive Protein (CRP) in human serum and plasma. The ELISA methodology is commonly used for serological evaluations. Antibodies to CRP have been attached to the inner surfaces of the microwell plate. During the initial incubation step, CRP in patient serum binds specifically to the immobilized antibody and remains in place after a wash step. A second antibody, which is conjugated to the enzyme horseradish peroxidase, reacts with CRP bound in the first step. In the wells where the second antibody remains bound, the enzyme catalyzes a color change in the substrate, tetramethylbenzidine (TMB). After the reaction is stopped, the color is read in an EIA plate reader.

AI/ML Overview

Here's an analysis of the provided text regarding the acceptance criteria and study for the Hemagen® CRP 150 Kit:

1. Table of Acceptance Criteria and Reported Device Performance

Acceptance Criteria Category	Specific Criteria (Implicitly Derived)	Reported Device Performance
Correlation with WHO Standard (CRP Standards Verification)	High degree of correlation with W.H.O International Standard for Human C-Reactive Protein (1st International Standard, Code 85/506).	"high degree of correlation that exists between the Kit standards and the W.H.O. Standard."
Equivalence to Predicate Device (Comparison Testing)	Linear relationship with the predicate device, evidenced by a regression slope of approximately +1.0 and a correlation coefficient > 0.90 for estimated CRP concentrations.	"linear relationship with a high degree of correlation exists between the estimated CRP concentrations for assayed serum samples as evidenced by an estimated regression slope of +1.0 and a correlation coefficient of > 0.90."
Performance with Serum and Plasma	Provide accurate estimates of CRP concentrations in both human serum and plasma.	"it can provide accurate estimates of CRP concentrations in both human serum and plasma."
Interference by Lipemia, Hemolysis, Icterus	Hemoglobin concentrations of ≤ 500 mg/dL, lipid concentrations of ≤ 3,000 mg/dL, and bilirubin concentrations of 20 mg/dL should not significantly affect assay results.	"Samples with hemgall on concentrations of ≤ 500 mg/dL, lipid concentrations of ≤ 3,000 mg/dL, and bilirubin concentrations of 20 mg/dL did not significantly affect the assay results."
Between-run reproducibility (Inter-Assay Precision)	(Implicitly based on CVs shown) Acceptable Coefficient of Variation (CV) for various CRP concentrations.	CVs ranging from 5% to 12% for different CRP levels (Mean µg/mL 1.4-32.5).
Within-run reproducibility (Intra-Assay Precision)	(Implicitly based on CVs shown) Acceptable Coefficient of Variation (CV) for various CRP concentrations.	CVs ranging from 5% to 25% for different CRP levels (Mean µg/mL 1.0-31.9).

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

CRP Standards Verification: Not explicitly stated, but it describes a "study...to demonstrate the high degree of correlation." Given it's a standard, it's likely a limited, controlled prospective assessment of the manufactured standards against the WHO standard.
Comparison Testing (Predicate Device): 18 human serum samples.
- Data Provenance: Not explicitly stated, but human serum samples imply clinical origin. No country of origin is mentioned. The study is retrospective in the sense that these samples are being tested concurrently on two devices.
- (Note: The text also mentions a previous predicate device submission where EIA was compared to latex agglutination with 166 human serum samples, indicating that previous data was also retrospective.)
Assay performance with Serum and Plasma: Two sets of plasma samples of 41 samples each (total 82 plasma samples, which were then converted to 41 serum samples).
- Data Provenance: "apparently healthy donors." No country of origin is mentioned. This is a prospective collection of samples for this specific study.
Interfering Substances: Not explicitly stated, but "samples with hemgall on concentrations... lipid concentrations... and bilirubin concentrations" suggests a controlled study where samples were spiked or selected to have these characteristics.
- Data Provenance: Not explicitly stated. Likely prospective or controlled in vitro preparation of samples.
Precision Studies (Inter-Assay & Intra-Assay): 8 serum samples for both.
- Data Provenance: Not explicitly stated, but "serum samples" imply clinical origin. This is a prospective study designed to assess repeatability and reproducibility.

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

There is no mention of experts being used to establish ground truth for this device's performance evaluation. The ground truth is primarily based on:

Comparison to an established international standard (WHO International Standard for Human C-Reactive Protein).
Comparison to a legally marketed predicate device.
The results of the test method itself, with precision and interference assessed internally.

4. Adjudication Method for the Test Set

None. Adjudication methods (like 2+1 or 3+1) are typically used when subjective expert interpretation is involved in establishing ground truth (e.g., radiology image interpretation). This device involves quantitative measurement, where ground truth is an objective value (e.g., from the WHO standard 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

No. This is not an AI-assisted diagnostic device, nor does it involve human "readers" or subjective interpretation in the way an MRMC study would apply. It's a quantitative immunoassay.

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

Yes, effectively. The entire study for the Hemagen® CRP 150 Kit assesses its standalone performance (the kit itself) in measuring CRP concentrations, without human interpretation being a variable. The "human-in-the-loop" here is the lab technician performing the assay, but the output (CRP concentration) is objective, not interpretive.

7. The Type of Ground Truth Used

CRP Standards Verification: The WHO International Standard for Human C-Reactive Protein (1st International Standard, Code 85/506) served as the ground truth/reference.
Comparison Testing: The predicate device (Hemagen® C-Reactive Protein Kit) served as the reference/ground truth for equivalence.
Assay performance with Serum and Plasma: The measured CRP concentrations in "apparently healthy donors" were considered the truth for assessing consistency across sample types.
Interfering Substances: The absence of significant effect on the assay results from known concentrations of interferents (hemoglobin, lipids, bilirubin) served as the ground truth for non-interference.
Precision Studies: The internal consistency of the device's measurements (mean, standard deviation, CV) formed the ground truth for repeatability and reproducibility.

8. The Sample Size for the Training Set

No training set is mentioned or applicable. This is a traditional immunoassay kit, not a machine learning or AI model that requires a "training set." The development of the kit (e.g., antibody selection, assay parameters) would involve internal R&D and validation, but not a formally defined "training set" in the context of AI.

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

Not applicable, as there is no training set for this type of device.

Summary

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

MAR 1 2 1996

K260334

510(k) Summary Hemagen ® CRP 150 Kit

Submitter's Name/Contact Person

Joseph M. Califano, Manager, Regulatory Affairs

Address

..............................................................................................................................................................................

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

Phone:	(617) 890-3766
Fax:	(617) 890-3748

Date Prepared

19 January 1996

2 Device Names

Trade Name: Hemagen ® CRP 150 Kit Common Name: C-Reactive Protein Assay (EIA method) C-reactive protein immunological test system Classification Name: (per 21 CFR 866.5270)

3 Predicate Device

Hemagen ® C-Reactive Protein Kit (EIA method) Reference Docket No: K 944288

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

510/k) Summary Hemagen ® CRP 150 Kit

4 Description of Device

An enzyme-linked immunosorbent assay (ELISA) designed for the semiquantitative detection of C-Reactive Protein (CRP) in human serum and plasma.

The ELISA methodology is commonly used for serological evaluations. Antibodies to CRP have been attached to the inner surfaces of the microwell plate. During the initial incubation step, CRP in patient serum binds specifically to the immobilized antibody and remains in place after a wash step.

A second antibody, which is conjugated to the enzyme horseradish peroxidase, reacts with CRP bound in the first step. In the wells where the second antibody remains bound, the enzyme catalyzes a color change in the substrate, tetramethylbenzidine (TMB). After the reaction is stopped, the color is read in an EIA plate reader.

5 Intended Use of Device

6.(A) Technological Characteristics

The Hemagen CRP 150 Kit is an enzyme-linked immunosorbent assay with the following features:

i. The assay's detection range is 1ug/mL to 50 ug/mL of CRP.
ii. A positive control.
iii. A set of CRP standards.
iv. The HRP conjugate is supplied as a liquid.

The predicate device is also an enzyme-linked immunosorbent assay.

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

510(k) Summary Hemagen ® CRP 150 Kit

6.(B) Performance Data

. Verification of CRP Standards

The CRP Standards have been compared to the W.H.O International Standard for Human C-Reactive Protein (1st International Standard, Code 85/506). A study was conducted to demonstrate the high degree of correlation that exists between the Kit standards and the W.H.O. Standard.

11. Comparison Testing

Eighteen human serum* samples with CRP concentrations ranging from 1 to 100 ug/mL were evaluated concurrently with both the proposed device and the predicate device to demonstrate the equivalence of the CRP concentrations estimated with each of the kits in accordance with the instructions in their respective package inserts.

(*In the submission for the predicate device, the EIA methodology was shown to be substantially equivalent to a latex aggluntination method by concurrent comparison with 166 human serum samples.}

Analysis of the results of this study indicated that a linear relationship with a high degree of correlation exists between the estimated CRP concentrations for assayed serum samples as evidenced by an estimated regression slope of +1.0 and a correlation coefficient of > 0.90.

III. Assay performance with Serum and Plasma

Two sets of plasma samples of 41 samples each from apparently healthy donors were selected. Half of the volume of each sample was converted to serum by recalcification using a standard Ca2+ /thrombin methodology.

All of the plasma and converted serum samples were assayed for CRP concentrations with the Hemagen CRP 150 Kit in accordance with the Draft package insert.

The results of the evaluation with proposed device indicate that it can provide accurate estimates of CRP concentrations in both human serum and plasma.

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

510(k) Summary Hemagen ® CRP 150 Kit

IV. Interfering Substances

Lipemic, hemolytic, and iteric samples were evaluated with the Hemagen CRP 150 Kit following NCCLS Proposed Guideline, "Interference Testing in Cinical Chemistry" Document EP7-P ISSN 0273-3099. Samples with hemgall on concentrations of ≤ 500 mg/dL, lipid concentrations of ≤ 3,000 mg/dL, and bilirubin concentrations of 20 mg/dL did not significantly affect the assay results.

V. Precision Studies

Between-run reproducibility {Inter Assay}

Eight serum samples were assayed five times each, twice a day, on five different days (a total of 50 readings per sample). The results are as follows:

Sample	Mean µg/mL	Std. Deviation	C.V.
1	1.4	0.2	12
2	1.7	0.2	11
3	4.0	0.3	7
4	10.0	0.8	8
5	23.6	1.9	8
6	24.9	1.9	8
7	32.5	2.2	7
8	30.2	1.6	5

Within-run reproducibility {Intra Assay}

Eight serum samples were assayed 19 consecutive times in single runs. The results are as follows:

Sample	Mean µg/mL	Std. Deviation	C.V.
1	1.0	0.2	17
2	1.1	0.3	25
3	4.0	0.7	17
4	10.6	1.6	15
5	22.8	1.1	5
6	25.9	1.5	6
7	31.9	1.9	6
8	28.1	3.2	11

Conclusions

The results of the comparative studies support the claim that the Hemagen kit is a safe and effective in vitro diagnostic test and is substantially equivalent to the predicate device.

Regulation Number and Section

§ 866.5270 C-reactive protein immunological test system.

(a)
Identification. A C-reactive protein immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the C-reactive protein in serum and other body fluids. Measurement of C-reactive protein aids in evaluation of the amount of injury to body tissues.(b)
Classification. Class II (performance standards).