WAKO TOTAL BILIRUBIN V, MODELS 410-22701, 998-23291, 416-22801, 990-23191

K053131 · Wako Chemicals USA, Inc. · JFM · Dec 30, 2005 · Clinical Chemistry

Device Facts

• Record ID: K053131
• Device Name: WAKO TOTAL BILIRUBIN V, MODELS 410-22701, 998-23291, 416-22801, 990-23191
• 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

Indications for Use

Indication of serum and plasma bilirubin is useful in the screening of liver function disorders or in the diagnosis of jaundice.

Device Story

Wako Total Bilirubin V is an in vitro diagnostic reagent for measuring total bilirubin in serum or 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 total bilirubin to biliverdin, causing a decrease in yellow absorbance. The concentration is determined by measuring absorbance before and after vanadate oxidation. The assay is intended for use in clinical laboratory settings to assist healthcare providers in screening for liver function disorders or diagnosing jaundice. It offers improved stability and reduced interference from coexistent serum substances compared to traditional diazo coupling or enzymatic methods.

Clinical Evidence

No clinical data provided. Substantial equivalence is based on analytical performance and comparison to the predicate device.

Technological Characteristics

Dual-reagent enzymatic colorimetric system. Sensing principle: vanadate oxidation of bilirubin to biliverdin measured via 451 nm absorbance. Reportable range: 0.1-40 mg/dL. Storage: 2-35°C. Compatible with ADVIA 1650 analyzer. Matrix: serum and plasma.

Indications for Use

Indicated for screening liver function disorders or diagnosing jaundice in patients requiring serum or plasma bilirubin testing. Not tested in neonates. Prescription use only.

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 Total Bilirubin V (k970985)

Submission Summary (Full Text)

{0}

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

A. 510(k) Number:
k053131

B. Purpose for Submission:
New Device

C. Measurand:
Bilirubin, Total

D. Type of Test:
Enzymatic Colorimetric

E. Applicant:
Wako Chemicals USA, Inc.

F. Proprietary and Established Names:
Wako Total 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 Total 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 Total Bilirubin V

2. Predicate 510(k) number(s):
k970985

3. Comparison with predicate:
| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Method | Colorimetric | Colorimetric |
| Linearity | 0.1 to 40 mg/dL | 0.1 to 40 mg/dL |
| Storage Temp. | 2 -35° C | 2 -35° C |

{2}

| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| 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 Total Bilirubin V uses an enzymatic method for bilirubin detection. Total bilirubin reacts with vanadate under acidic conditions, and is oxidized to biliverdin. The resulting absorbance change is colorimetrically measured at 451 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 Total Bilirubin V with 22 and/or 23 replicates of five sample concentrations.

| | Replicate | Mean (mg/dL) | S.D. | C.V. (%) |
| --- | --- | --- | --- | --- |
| Sample 1 | 23 | 0.30 | 0.01 | 1.89 |
| Sample 2 | 22 | 0.80 | 0.00 | 0.00 |
| Sample 3 | 23 | 1.50 | 0.02 | 1.11 |
| Sample 4 | 22 | 20.06 | 0.13 | 0.63 |
| Sample 5 | 22 | 36.84 | 0.26 | 0.71 |

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

{3}

| Level | # of days | Mean (mg/dL) | S.D. | C.V. (%) |
| --- | --- | --- | --- | --- |
| Low | 20 | 1.0 | 0.29 | 2.92 |
| High | 20 | 7.1 | 0.194 | 2.27 |

An accuracy of recovery study was conducted with the Wako Total Bilirubin V by running dilutions of pooled serum with saline or calibrators in replicates of 5.

| | Sample 1 | Sample 2 | Sample 3 | Sample 4 | Sample 5 | Sample 6 |
| --- | --- | --- | --- | --- | --- | --- |
| | | | | | | |
| Added (mg/dL) | 0 | 1.8 | 5.5 | 13.1 | 27.9 | 35.3 |
| Expected (mg/dL) | 1.7 | 3.5 | 7.2 | 14.8 | 29.6 | 37.0 |
| Obtained mean (mg/dL) | 1.64 | 3.48 | 7.06 | 14.68 | 29.34 | 36.84 |
| Recovery % | 96% | 99% | 98% | 99% | 99% | 100% |

b. Linearity/assay reportable range:

A dilution linearity study was conducted and the sponsor claims a reportable range of 0.1 to $40\mathrm{mg / dL}$ . When total bilirubin concentration exceeds 40 $\mathrm{mg / dL}$ , 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 0.46 to $38.99\mathrm{mg / dL}$ were analyzed and the linear regression equation was reported as $y = 0.981x + 0.044$ and $r = 0.999$ .

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

The Wako Total Bilirubin is stable when stored at 2 to $35^{\circ}\mathrm{C}$ until its expiration date.

d. Detection limit:

The minimum level of detection is $0.1\mathrm{mg / dL}$ 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 $0.1\mathrm{mg / dL}$ .

e. Analytical specificity:

No interference was observed by ascorbic acid up to $50\mathrm{mg / dL}$ , hemoglobin up to $500\mathrm{mg / dL}$ and intrafat up to $2\%$ . Anticoagulants were also studied and no interference was detected with EDTA, citrate, oxalate, sodium flouride and

{4}

heparin.

f. Assay cut-off:

Not applicable.

2. Comparison studies:

a. Method comparison with predicate device:

The Wako Total Bilirubin V was compared to the Wako Total Bilirubin V that was previously cleared in 1997. A comparison of bilirubin measurements by the current device (y) and the predicate device (x) was performed using 89 serum samples. The equation of $y = 0.990x + 0.005$ with an $r = 0.999$ was obtained with using the ADVIA 1650 instrument.

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 0.46 to $38.99\mathrm{mg/dL}$ 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 the following equation: $y = 0.981x + 0.43$ and $r = 0.99$.

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:

{5}

The sponsor states that the expected value of total bilirubin in serum and plasma is 0.2 to 1.0 mg/dL as recommended in Tietz Textbook of Clinical Chemistry by Carl A. Burtis and Edward R. Ashwood.

**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.