WAKO DIRECT BILIRUBIN V, MODELS 996-23591, 412-22901, 992-23691, 998-23791

K053132 · Wako Chemicals USA, Inc. · JFM · Dec 30, 2005 · Clinical Chemistry

Device Facts

• Record ID: K053132
• Device Name: WAKO DIRECT BILIRUBIN V, MODELS 996-23591, 412-22901, 992-23691, 998-23791
• Applicant: Wako Chemicals USA, Inc.
• Product Code: JFM · Clinical Chemistry
• Decision Date: Dec 30, 2005
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1110
• Device Class: Class 2
• Attributes: Pediatric

Indications for Use

Determination of serum and plasma bilirubin is useful in the screening of liver function disorders or in the diagnosis of jaundice. For prescription use only. This assay has not been tested in neonates.

Device Story

Wako Direct Bilirubin V is an in vitro diagnostic reagent for measuring direct bilirubin concentration in serum and plasma. The device utilizes a chemical oxidation method where a sample is mixed with a reagent containing detergent and vanadate at approximately pH 3. This process oxidizes direct bilirubin to biliverdin, causing a decrease in yellow absorbance specific to bilirubin. The concentration is calculated by measuring absorbance before and after vanadate oxidation. The assay is intended for use in clinical laboratory settings by trained personnel. Results assist healthcare providers in screening for liver function disorders and diagnosing jaundice, facilitating clinical management of patients with suspected hepatic or biliary conditions.

Clinical Evidence

No clinical data provided. Substantial equivalence is based on bench testing demonstrating performance correlation with conventional methods and the addition of plasma as a validated sample type.

Technological Characteristics

Liquid, ready-to-use reagent. Principle: Chemical oxidation using vanadate at pH 3. Measures absorbance decrease at yellow wavelength. Intended for use on clinical chemistry analyzers.

Indications for Use

Indicated for the determination of bilirubin in serum and plasma samples to screen for liver function disorders or diagnose jaundice in patients.

Regulatory Classification

Identification

A bilirubin (total or direct) test system is a device intended to measure the levels of bilirubin (total or direct) in plasma or serum. Measurements of the levels of bilirubin, an organic compound formed during the normal and abnormal distruction of red blood cells, if used in the diagnosis and treatment of liver, hemolytic hematological, and metabolic disorders, including hepatitis and gall bladder block.

Predicate Devices

• Wako Direct Bilirubin V (k970986)

Reference Devices

• Wako 30R Bilirubin V

Submission Summary (Full Text)

{0}

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

A. 510(k) Number:
k053132

B. Purpose for Submission:
New Device

C. Measurand:
Bilirubin, Direct

D. Type of Test:
Enzymatic Colorimetric

E. Applicant:
Wako Chemicals USA, Inc.

F. Proprietary and Established Names:
Wako Direct Bilirubin V

G. Regulatory Information:
1. Regulation section:
21 CFR 862.1110 Bilirubin (Total or Direct) Test System
2. Classification:
Class II
3. Product code:
JFM
4. Panel:
75, Chemistry

{1}

H. Intended Use:

1. Intended use(s):
See indications for use below.

2. Indication(s) for use:
Determination of serum and plasma bilirubin is useful in the screening of liver function disorders or in the diagnosis of jaundice.

3. Special conditions for use statement(s):
For prescription use only.
This assay has not been tested in neonates.

4. Special instrument requirements:
ADVIA 1650 Analyzer

I. Device Description:

The Wako Direct Bilirubin V is a dual reagent system. Both reagents contain stabilizers and/or buffers. To calibrate the test kit, a previously cleared calibrator is used that has values determined by a similar method.

J. Substantial Equivalence Information:

1. Predicate device name(s):
Wako Direct Bilirubin V

2. Predicate 510(k) number(s):
k970986

3. Comparison with predicate:
| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Method | Colorimetric | Colorimetric |
| Linearity | 0.1 to 20 mg/dL | 0.1 to 20 mg/dL |
| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |

{2}

| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Storage Temp. | 2 -10° C | 2 -35° C |
| Matrix | Serum and Plasma | Serum |

# K. Standard/Guidance Document Referenced (if applicable):

CLSI EP5-T2 Evaluation of Precision Performance of Clinical Chemistry Devices

CLSI Protocol EP9-A Method Comparison and Bias Estimation Using Patient Samples

CLSI Protocol EP6-A Evaluation of the Linearity of Quantitative Analytical Methods; Approved Guideline

CLSI EP7-P Interference Testing in Clinical Chemistry; Approved Guideline- Second Edition

# L. Test Principle:

The Wako Direct Bilirubin V uses an enzymatic method for bilirubin detection. Direct bilirubin reacts with vanadate under acidic conditions, and is oxidized to biliverdin. The resulting absorbance change is colorimetrically measured at $451~\mathrm{nm}$ .

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

# 1. Analytical performance:

All studies were conducted on the ADVIA 1650 analyzer unless stated otherwise.

# a. Precision/Reproducibility:

Within-run precision was conducted with Wako Direct Bilirubin V with 22 or 23 replicates of five sample concentrations.

| | Replicate | Mean (mg/dL) | S.D. | C.V. (%) |
| --- | --- | --- | --- | --- |
| Sample 1 | 23 | 0.3 | 0.01 | 1.87 |
| Sample 2 | 23 | 1.5 | 0.02 | 1.11 |
| Sample 3 | 22 | 1.3 | 0.03 | 2.37 |
| Sample 4 | 22 | 9.9 | 0.07 | 0.73 |
| Sample 5 | 22 | 19.9 | 0.16 | 0.83 |

Total precision was conducted on two levels of pooled sera, in the abnormal and normal ranges. Samples were run in duplicate for 20 days.

| Level | # of days | Mean | S.D. | C.V. (%) |
| --- | --- | --- | --- | --- |

{3}

| | | (mg/dL) | | |
| --- | --- | --- | --- | --- |
| Low | 20 | 0.4 | 0.013 | 3.51 |
| High | 20 | 0.7 | 0.24 | 3.75 |

An accuracy study was conducted with the Wako Direct Bilirubin V by running 6 human serum samples in replicates of 5.

| | Sample 1 | Sample 2 | Sample 3 | Sample 4 | Sample 5 | Sample 6 |
| --- | --- | --- | --- | --- | --- | --- |
| Added (mg/dL) | 0 | 1.1 | 3.6 | 7.6 | 14.6 | 18.6 |
| Expected (mg/dL) | 1.4 | 2.5 | 5.0 | 9.0 | 16.0 | 20.0 |
| Observed mean (mg/dL) | 1.4 | 2.48 | 4.92 | 8.88 | 16.3 | 20.1 |
| Recovery % | 100% | 99% | 98% | 99% | 102% | 101% |

## b. Linearity/assay reportable range:

A dilution linearity study was conducted and the sponsor claims a linear range of 0.1 to 20 mg/dL. The labeling informs user that if the direct bilirubin concentration exceeds 20 mg/dL, a 1:1 sample dilution with saline is required and the result is multiplied by 2. Seventy two plasma and serum pairs that ranged from 0.07 to 22.17 mg/dL were analyzed and the linear regression equation was reported as y=0.985x + 0.055 and r=0.999.

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

The Wako Direct Bilirubin is stable when stored at 2 to 10° C until its expiration date.

## d. Detection limit:

The minimum level of detection is 0.1 mg/dL and was calculated by running a known zero sample (water) for 21 replicates. The mean plus 2 SD was used to calculate the minimum level of detection of 0.1 mg/dL.

## e. Analytical specificity:

No interference was observed by ascorbic acid up to 50 mg/dL, hemoglobin up to 500 mg/dL and Intrafat up to 2%. Anticoagulants were also studied and no interference was detected with EDTA, citrate, oxalate, sodium fluoride and heparin.

## f. Assay cut-off:

{4}

Not applicable.

2. Comparison studies:

a. Method comparison with predicate device:

The Wako Direct Bilirubin V was compared to the Wako 30R Bilirubin V that was previously cleared in 1991. A comparison of bilirubin measurements by the current device (y) and the predicate device (x) was performed using 84 serum samples. The equation of $y = 0.971x + 0.020$ with a $r = 0.912$ was obtained with using the Hitachi 911.

b. Matrix comparison:

A comparison of 36 matched serum and plasma samples (31 patient samples and 5 spiked samples run in duplicate) that ranged from 0.07 to $22.2\mathrm{mg / dL}$ was performed. Of the 36 matched serum and plasma samples, 5 were spiked with a concentrated form of human bilirubin calibrator to evaluate the comparison at the high end of the linear range. The 31 patient samples were drawn fresh daily and run in duplicates for 7 days. The comparison was preformed on the ADVIA 1650 analyzer and gave a correlation coefficient of $r = 0.9989$ and a regression equation of $y = 0.985x + 0.05$.

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 states that the expected value of direct bilirubin in serum and plasma is $0.0 - 0.2\mathrm{mg / dL}$ as recommended in Tietz Textbook of Clinical Chemistry by Carl A. Burtis and Edward R. Ashwood.

{5}

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.