N LATEX CYSTATIN

K041878 · Dade Behring, Inc. · NDY · Aug 16, 2004 · Clinical Chemistry

Device Facts

• Record ID: K041878
• Device Name: N LATEX CYSTATIN
• Applicant: Dade Behring, Inc.
• Product Code: NDY · Clinical Chemistry
• Decision Date: Aug 16, 2004
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1225
• Device Class: Class 2

Indications for Use

N Latex Cystatin C is an in vitro diagnostics kit containing reagents for the quantitative determination of cystatin C in human serum and heparinized plasma by means of particle-enhanced immunonephelometry using BN™ Systems. Cystatin C measurements are used in the diagnosis and treatment of renal diseases. This product is for prescription use only.

Device Story

N Latex Cystatin C is an in vitro diagnostic reagent kit used for quantitative measurement of cystatin C in human serum and heparinized plasma. The device utilizes particle-enhanced immunonephelometry on BN™ Systems. Polystyrene particles coated with anti-human cystatin C antibodies aggregate when exposed to patient samples containing cystatin C. These aggregates scatter light; the intensity of scattered light is proportional to the cystatin C concentration. Results are determined by comparing sample light scatter against a standard of known concentration. The assay is performed in clinical laboratory settings by trained personnel. Clinicians use the resulting cystatin C measurements to aid in the diagnosis and management of renal disease.

Clinical Evidence

No clinical data provided; substantial equivalence is based on bench testing and comparison to the predicate device.

Technological Characteristics

Reagents consist of polystyrene particles coated with specific antibodies to human cystatin C. Principle of operation is particle-enhanced immunonephelometry. The device is designed for use with BN™ Systems. It is an in vitro diagnostic kit for quantitative analysis.

Indications for Use

Indicated for the quantitative determination of cystatin C in human serum and heparinized plasma to aid in the diagnosis and treatment of renal diseases.

Regulatory Classification

Identification

A creatinine test system is a device intended to measure creatinine levels in plasma and urine. Creatinine measurements are used in the diagnosis and treatment of renal diseases, in monitoring renal dialysis, and as a calculation basis for measuring other urine analytes.

Predicate Devices

• N Latex Cystatin C (k003503)

Submission Summary (Full Text)

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510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
DEVICE ONLY TEMPLATE

A. 510(k) Number:
k041878

B. Purpose for Submission:
Modification to existing device Dade Behring, Inc., N Latex Cystatin C (k003503)

C. Analyte:
Cystatin C

D. Type of Test:
Quantitative Particle-enhanced immunonephelometry

E. Applicant:
DADE BEHRING, INC.

F. Proprietary and Established Names:
N LATEX CYSTATIN C

G. Regulatory Information:
1. Regulation section:
21CFR §862.1225 -Creatinine test system.
2. Classification:
Class 2
3. Product Code:
NDY
4. Panel:
Chemistry (75)

H. Intended Use:
1. Intended/Indication(s) for use:
N Latex Cystatin C is an in vitro diagnostics kit containing reagents for the quantitative determination of cystatin C in human serum and heparinized plasma by means of particle-enhanced immunonephelometry using BN™ Systems. Cystatin C measurements are used in the diagnosis and treatment of renal diseases.
2. Special condition for use statement(s):
This product is for prescription use only.
3. Special instrument Requirements:
BN™ Systems

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I. Device Description:

The N Latex Cystatin C assay kit consists of a suspension of polystyrene particles coated with specific antibodies to human cystatin C, rabbit immunoglobulin in a buffered solution, an aqueous solution of polyethylene glycol sorbitan monolaureate and polyethylene glycol ether, and two lyophilized control materials.

J. Substantial Equivalence Information:

1. Predicate device name(s):
N Latex Cystatin C

2. Predicate K number(s):
k003503

3. Comparison with predicate
The two products have the same intended use, operating principle and reagent composition.

| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Intended Use | N Latex Cystatin C is an in vitro diagnostics kit containing reagents for the quantitative determination of cystatin C in human serum and heparinized plasma by means of particle-enhanced immunonephelometry using the BNTM Systems. Cystatin C measurements are used in the diagnosis and treatment of renal diseases. | N Latex Cystatin C is an in vitro diagnostics kit containing reagents for the quantitative determination of cystatin C in human serum and heparinized plasma by means of particle-enhanced immunonephelometry using BNTM Systems. Cystatin C measurements are used in the diagnosis and treatment of renal diseases. |
| Principle | Polystyrene particles coated with specific antibodies to human cystatin C are aggregated when mixed with samples containing human cystatin C. These aggregates scatter a beam of light passed through the sample. The intensity of the scattered light is proportional to the concentration of the relevant protein in the sample. The result is evaluated by comparison with a standard of known concentration. | Polystyrene particles coated with specific antibodies to human cystatin C are aggregated when mixed with samples containing human cystatin C. These aggregates scatter a beam of light passed through the sample. The intensity of the scattered light is proportional to the concentration of the relevant protein in the sample. The result is evaluated by comparison with a standard of known concentration. |
| Sample Type | Serum or heparinized plasma | Serum or heparinized plasma |
| Instrumentation | Nephelometry (BNTM Systems) | Nephelometry (BNTM Systems) |

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| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| 5. Kit Components | N Cystatin C Reagent - liquid
N Cystatin C Supplementary Reagent A - liquid
N Cystatin C Supplementary Reagent B - liquid
N Cystatin C Control Level 1 - lyophilized
N Cystatin C Control Level 2 - lyophilized | N Cystatin C Reagent - lyophilized
N Cystatin C Supplementary Reagent A - liquid
N Cystatin C Supplementary Reagent B - liquid
N Cystatin C Control - lyophilized |

K. Standard/Guidance Document Referenced (if applicable):
None referenced

L. Test Principle:
Polystyrene particles coated with specific antibodies to human cystatin C are aggregated when mixed with samples containing human cystatin C. These aggregates scatter a beam of light passed through the sample. The intensity of the scattered light is proportional to the concentration of the relevant protein in the sample. The result is evaluated by comparison with a standard of known concentration.

M. Performance Characteristics (if/when applicable):
1. Analytical performance:
a. Precision/Reproducibility:
The N Latex Cystatin C assay was used to measure cystatin C concentrations in N Cystatin C Control Level 1 and 2, three serum pools and three plasma pools ranging from 0.8 to 7.1 mg/L. Duplicate determinations from two runs over twenty days were performed using a BN™ System
Within run % C.V. ranged from 1.5 to 3.1
Between run % C.V. ranged from 1.5 to 3.5
Total % C.V. ranged from 2.4 to 4.3
b. Linearity/assay reportable range:
A sample with high concentration of analyte was serially diluted down to the lower measuring range (approximately 10% dilution steps). Each dilution was tested in replicates of five, and the mean % recovery was determined (% Recovery = mean - measured concentration x 100 / theoretical concentration). In addition, the linear regression [x-axis: theoretical concentration vs. y-axis: measured concentration] was calculated for the analyte. The acceptance criterion was established as the % recovery between 80 and 120 %, with a slope between 0.9 and 1.1 and correlation coefficient of ≥0.95.
c. Traceability (controls, calibrators, or method):
Not Applicable - subject of k003503

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d. Detection limit:
Analytical sensitivity is defined as the minimal detectable level of analyte, which can be determined. This value was calculated as the mean signal of twenty replicates of N-Diluent + 2.0 SD – intercept/slope. The analytical sensitivity acceptance criterion was established as the calculated sensitivity must be less than the lowest calibrator value and was determined to be 0.05 mg/L.

e. Analytical specificity:
No interference was observed with immunosuppressive drugs (Cyclosporine, Tacrolimus, Sirolimus, Mycophenolate or Azathioprine). Interference from monoclonal or polyclonal antibodies used in the treatment of transplant patients has not been evaluated.

f. Assay cut-off:
Not Applicable - subject of k003503

2. Comparison studies:
a. Method comparison with predicate device:
The current N Latex Cystatin C assay (lyophilized) was compared to the modified N Latex Cystatin C assay (liquid) by evaluating 70 serum samples ranging from 0.56 to 7.5 mg/L.

Method Comparison Study
| Assay | (n=) | Slope | Intercept | Correlation Coefficient |
| --- | --- | --- | --- | --- |
| N Latex Cystatin C | 70 | 0.99 | -0.002 | 0.999 |

b. Matrix comparison:
Not applicable - subject of k003503

3. Clinical studies:
a. Clinical sensitivity:
Not applicable - subject of k003503
b. Clinical specificity:
Not Applicable - subject of k003503
c. Other clinical supportive data (when a and b are not applicable):

4. Clinical cut-off:
Not Applicable - subject of k003503

5. Expected values/Reference range:
Not Applicable - subject of k003503

N. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.