DIAZYME APOLIPOPROTEIN B ASSAY, MODEL DZXXX-X; B CALIBRATOR, MODEL DZXXX

K073488 · Diazyme Laboratories · MSJ · Mar 7, 2008 · Clinical Chemistry

Device Facts

• Record ID: K073488
• Device Name: DIAZYME APOLIPOPROTEIN B ASSAY, MODEL DZXXX-X; B CALIBRATOR, MODEL DZXXX
• Applicant: Diazyme Laboratories
• Product Code: MSJ · Clinical Chemistry
• Decision Date: Mar 7, 2008
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1475
• Device Class: Class 1

Intended Use

The Diazyme Apolipoprotein B Assay is intended for the quantitative determination of apolipoprotein B (apo B) in serum. It can be used as an aid for assessing the risk of coronary artery disease. For in vitro Diagnostic use. Calibrator: For calibration of the Diazyme Apolipoprotein B Assay in serum. For in vitro Diagnostic Use. Controls: To monitor the performance of Diazyme Apolipoprotein B Assay in serum. For in vitro Diagnostic Use.

Device Story

Diazyme Apolipoprotein B Assay is an in vitro diagnostic immunoassay for serum samples. It utilizes a turbidimetric principle where sample apo B reacts with specific anti-human-apoB antiserum to form an insoluble complex. The resulting turbidity is measured at 340 nm on clinical chemistry analyzers (e.g., Hitachi 917). The device is intended for use by laboratory professionals in clinical settings. Output is a quantitative concentration value (mg/dL) derived from a standard curve. This value assists clinicians in evaluating coronary artery disease risk. The assay includes reagents, calibrators, and controls.

Clinical Evidence

No clinical studies were performed. Evidence consists of analytical bench testing. Method comparison study (n=62) against the predicate device showed a correlation coefficient of 0.9864, slope of 1.0143, and y-intercept of -4.3806. Precision studies (CLSI EP5-A) showed total CVs ranging from 2.1% to 4.8%. Linearity (CLSI EP6-A) demonstrated R²=0.9992. Analytical specificity testing confirmed no significant interference from ascorbic acid, bilirubin, hemoglobin, triglycerides, or Apo A-1.

Technological Characteristics

Turbidimetric immunoassay. Reagents: buffer (polyethylene glycol, Tris/HCl, NaCl) and anti-human-apoB antibody. Requires clinical chemistry analyzer with 340 nm absorbance capability and 37°C temperature control. Calibrators are human serum-derived and traceable to WHO/IFCC standards. Performance validated per CLSI guidelines (EP5-A, EP6-A, EP7-A, EP9-A, EP17-A).

Indications for Use

Indicated for quantitative determination of human Apolipoprotein B in serum to aid in assessing coronary artery disease risk. For in vitro diagnostic use.

Regulatory Classification

Identification

A lipoprotein test system is a device intended to measure lipoprotein in serum and plasma. Lipoprotein measurements are used in the diagnosis and treatment of lipid disorders (such as diabetes mellitus), atherosclerosis, and various liver and renal diseases.

Predicate Devices

• K-Assay Apo B Assay (k993354)

Submission Summary (Full Text)

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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY TEMPLATE

A. 510(k) Number:
k073488

B. Purpose for Submission:
New Device

C. Measurand:
Apolipoprotein B assay

D. Type of Test:
Immunoassay

E. Applicant:
Diazyme Laboratories Division, General Atomics

F. Proprietary and Established Names:
Diazyme Apolipoprotein B Assay

A. Regulatory Information:

| Product Code | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| MSJ | Class II | 862.1475 | Chemistry (75) |
| JIT | Class II | 862.1150 | Chemistry (75) |
| JJX | Class I reserved | 862.1660 | Chemistry (75) |

H. Intended Use:

1. Intended use(s):
The Diazyme Apolipoprotein B Assay is intended for the quantitative determination of apolipoprotein B (apo B) in serum. It can be used as an aid for assessing the risk of coronary artery disease. For in vitro Diagnostic use.
Calibrator: For calibration of the Diazyme Apolipoprotein B Assay in serum.
Controls: To monitor the performance of Diazyme Apolipoprotein B Assay in serum.

2. Indication(s) for use:
See intended use (above).

3. Special conditions for use statement(s):
For Prescription Use Only.

4. Special instrument requirements:
Any instrument with a temperature control of $37 \pm 0.5^{\circ} \mathrm{C}$ that is capable of

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reading absorbance accurately at 340 nm.

I. Device Description:
Included in the assay kit are two reagents, and a calibrator. Reagent 1 contains buffer including polyethylene glycol, Tris/HCl and Sodium chloride. Reagent 2 contains the anti-human-apoB antibody.
The calibrators are prepared from human serum. Each serum donor unit used in the preparation of this product has been tested and found to be non-reactive for HBsAg, HIV and HCV.

J. Substantial Equivalence Information:
1. Predicate device name(s):
K-Assay Apo B Assay
2. Predicate K number(s):
k993354
3. Comparison with predicate:

| Similarities | | |
| --- | --- | --- |
| Item or Characteristic | Device | Predicate (k993354) |
| Intended Use | Quantitative determination of Apo B to evaluate coronary disease risk | Same |
| Form | Lyophilized form | Same |
| Sample Type | Human Serum | Same |
| Calibrator Traceability | Diazyme Apolipoprotein B calibrator value is traceable to the WHO/IFCC Reference Standard. | Same |
| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Test Principle | Turbidometric measurement of a immune complex of Apo B and specific antiserum at 340 nm | Turbidometric measurement of a immune complex of Apo B and specific antiserum at 600 nm |
| Measuring Range | 25 – 160 mg/dL | 25 – 250 mg/dL |

K. Standard/Guidance Document referenced (if applicable):
CLSI EP5-A: Evaluation of Precision Performance of Clinical Chemistry Devices; Approved Guideline. Vol. 19 No.2, 2/1999

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CLSI EP6-A: Evaluation of the Linearity of Quantitative Measurement Procedures: A Statistical Approach; Approved Guideline. Vol. 23 No. 16, 4/2003

CLSI EP7-A: Interference Testing in Clinical Chemistry; Approved Guideline. Vol. 22 No. 27, 12/2002

CLSI EP9-A: Method Comparison and Bias estimation Using Patient Samples; Approved Guideline. Vol. 15, No. 17, 12/1995

CLSI EP17-A: Protocols for Determination of Limits of Detection and Limits of Quantitation; Approved Guideline. Vol. 24 No. 34, 10/2004

## L. Test Principle:

This method is based on the reaction of a sample containing human apo B and a specific antiserum to form an insoluble complex which can be measured turbidimetrically at 340 nm. The concentration of apo B can be determined by comparing sample results to a standard curve constructed from the absorbances of standards.

## M. Performance Characteristics (if/when applicable):

### 1. Analytical performance:

#### a. Precision/Reproducibility:

The precision of the Diazyme Apolipoprotein B assay was evaluated, according to CLSI EP5-A, in a study, using three levels of serum specimens containing low, medium and high levels of Apo B. They were tested with 2 runs per day in duplicates over 10 working days.

| | Level 1 | Level 2 | Level 3 |
| --- | --- | --- | --- |
| Serum Testing | 24 mg/dL Apo B | 100 mg/dL Apo B | 155 mg/dL Apo B |
| Std. Deviation | 3.6 mg/dL | 15 mg/dL | 23.25 mg/dL |
| Within-Run Precision | CV% = 1.4% | CV% = 1.4% | CV% = 1.2% |
| Total Precision | CV% = 4.8% | CV% = 3.9% | CV% = 2.1% |

#### b. Linearity/assay reportable range:

The claimed measuring range of this device is 25- 160 mg/dL. Eleven levels of samples were prepared in triplicate by diluting a serum control containing 157 mg/dL Apo B with saline according to CLSI EP6-A guidelines. Linear Regression analysis results obtained were as follows: Slope = 0.988, Intercept = 1.203 with an R² = 0.9992.

#### c. Traceability, Stability, Expected values (controls, calibrators, or methods):

Calibrator and Control Stability: The ApoB calibrator stability testing was performed in real time at 4°C, and as accelerated stability studies at 25°C and

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$37^{\circ}\mathrm{C}$ using two lots of the calibrator. Real-time stability tests are ongoing.

Calibrator Traceability: The Calibrator is traceable to WHO/IFCC standards.

# d. Detection limit:

Limit of Detection studies were performed following CLSI EP17-A. Five (5) serum samples containing low ApoB were diluted 100X with $7.5\%$ BSA in saline and tested with the ApoB reagent on the Hitachi 917 with 12 replicates each (a total of 60 measurements). The results are summarized as follows: $\mathrm{LoD} = \mathrm{LoB} + (1.645 * \mathrm{SD}$ Low Samples) $= 3.60 + (1.645 * 0.5556) = 3.60 + 0.91 = 4.51\mathrm{mg / dL}$

The LOD of the Diazyme ApoB assay was determined to be $4.51\mathrm{mg / dL}$

# e. Analytical specificity:

Interference testing was performed per CLSI guideline EP7-A. The following compounds were tested up to the concentrations detailed below with normal serum (containing $70\mathrm{mg / dL}$ of ApoB). There was $\leq \pm 10\%$ deviation in the observed concentration of ApoB.

| Interference Substance | Concentration |
| --- | --- |
| Ascorbic Acid | 10 mM |
| Bilirubin | 40 mg/dL |
| Bilirubin Conjugated | 40 mg/dL |
| Hemoglobin | 1000 mg/dL |
| Triglycerides | 1000 mg/dL |
| Apolipoprotein A-1 | 500 mg/dL |

Further, there was no cross-reactivity observed with Apo A-1 when tested up to a concentration of $500\mathrm{mg / dL}$ .

# f. Assay cut-off:

Not Applicable.

# 2. Comparison studies:

# a. Method comparison with predicate device:

The individual patient serum samples used for this study were from a certified commercial source and the assay was performed on a Hitachi 917 analyzer. To ensure the concentrations of Apo B were distributed across the reportable dynamic range claimed, additional Apo B samples were spiked with Apo B to achieve higher concentrations, or diluted with saline to reach lower concentrations. A total of 55 unaltered and 7 altered serum samples were used for the comparison experiment. The comparison results between the Diazyme Apolipoprotein B assay and the Kamiya Apo B reagent are summarized below:

For a total of 62 serum samples ranging from 29.6 to $241.1\mathrm{mg / dL}$ Apo B, the correlation coefficient between the two methods was 0.9864; the slope was 1.0143; and y intercept was -4.3806.

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The study was also analyzed using Passing-Bablok regression and the results obtained were:

Y = -2.8942 + 1.0082 X

Intercept: -2.8942

95% CI: -7.6091 to 0.3990

Slope: 1.0082

95% CI: 0.9720 to 1.0512

b. Matrix comparison:
Not Applicable.

3. Clinical studies:
a. Clinical Sensitivity:
Not Applicable.
b. Clinical specificity:
Not Applicable.
c. Other clinical supportive data (when a. and b. are not applicable):
Not Applicable.

4. Clinical cut-off:
Not Applicable.

5. Expected values/Reference range:
The sponsor claims a references range for Apolipoprotein B in adults of 63- 114 mg/dL.
Source citation: Fruchart, J-C (1986), Ann. Biol. Clin 44:116.

N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.

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