FASTPACK TSH IMMUNOASSAY

K052301 · Qualigen, Inc. · JLW · Jan 4, 2006 · Clinical Chemistry

Device Facts

• Record ID: K052301
• Device Name: FASTPACK TSH IMMUNOASSAY
• Applicant: Qualigen, Inc.
• Product Code: JLW · Clinical Chemistry
• Decision Date: Jan 4, 2006
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1690
• Device Class: Class 2

Indications for Use

The FastPack® TSH Immunoassay is a paramagnetic particle, chemiluminescence immunoassay for the in vitro quantitative determination of Thyroid-Stimulating Hormone in human plasma. The measurements of thyroid stimulating hormone (TSH) produced by the anterior pituitary are used in the diagnosis of thyroid or pituitary disorders. The FastPack® TSH is designed for use with the FastPack® System. The FastPack® TSH Calibrator is intended to calibrate the FastPack® System when used for the quantitative determination of TSH in human plasma. The FastPack® Controls are assayed quality control materials for the verification of the accuracy and precision of the FastPack® System when used for the quantitative determination of PSA in human serum and plasma, and TSH in human plasma.

Device Story

FastPack® TSH Immunoassay is a competitive chemiluminescence assay performed on the FastPack® System. Input: 100 µL human plasma sample. Process: Sample incubated with antibody solution (10 min, 37°C); transferred to paramagnetic particles (2 min, 37°C); unbound materials washed; chemiluminogenic substrate (ImmuGlow™) added. Output: Chemiluminescent glow measured by photomultiplier tube (PMT). System performs automated data reduction via internal microcomputer. Used in clinical settings for diagnostic testing. Results assist clinicians in diagnosing thyroid or pituitary disorders.

Clinical Evidence

Bench testing only. Method comparison study (n=93) against Abbott IMx Ultrasensitive hTSH II showed correlation (y = 0.91x + 1.26, r = 0.98). Analytical sensitivity 0.01 µIU/mL; functional sensitivity 0.13 µIU/mL. Precision evaluated across runs, analyzers, and reagent lots with %CVs ranging from 0.3% to 10.9%. Interference testing performed for bilirubin, hemoglobin, and triglycerides; specificity tested against LH, FSH, and hCG.

Technological Characteristics

Paramagnetic particle-based competitive chemiluminescence immunoassay. Uses alkaline phosphatase label and ImmuGlow™ (indoxyl-3-phosphate and lucigenin) substrate. Detection via photomultiplier tube. Automated processing at 37°C. Requires FastPack® System instrument. Storage 2-8°C. Software performs internal data reduction.

Indications for Use

Indicated for the quantitative determination of TSH in human plasma to aid in the diagnosis of thyroid or pituitary disorders.

Regulatory Classification

Identification

A thyroid stimulating hormone test system is a device intended to measure thyroid stimulating hormone, also known as thyrotrophin and thyrotrophic hormone, in serum and plasma. Measurements of thyroid stimulating hormone produced by the anterior pituitary are used in the diagnosis of thyroid or pituitary disorders.

Predicate Devices

• Abbott Laboratories IMx Ultrasensitive hTSH II (k942566)

Submission Summary (Full Text)

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

A. 510(k) Number:
k052301

B. Purpose for Submission:
Clearance of a new device

C. Measurand:
Thyrotropin (TSH)

D. Type of Test:
Quantitative Chemiluminescence Immunoassay

E. Applicant:
Qualigen, Inc.

F. Proprietary and Established Names:
FastPack® TSH Immunoassay

G. Regulatory Information:

1. Regulation section:
21 CFR § 862.1690, Thyroid stimulating hormone test system; 862.1660, Quality control material (assayed and unassayed); 862.1150, Calibrator

2. Classification:
Class II (Assay), Class I (Control), Class II (Calibrator)

3. Product code:
JLW, Radioimmunoassay, thyroid-stimulating hormone; JJX, Quality control material (assayed and unassayed); JIT, Calibrator

4. Panel:
Clinical Chemistry (75)

H. Intended Use:

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

2. Indication(s) for use:
The FastPack® TSH Immunoassay is a paramagnetic particle, chemiluminescence immunoassay for the in vitro quantitative determination of Thyroid-Stimulating Hormone in human plasma. The measurements of thyroid stimulating hormone (TSH) produced by the anterior pituitary are used in the diagnosis of thyroid or pituitary disorders. The FastPack® TSH is designed for use with the FastPack® System.

The FastPack® TSH Calibrator is intended to calibrate the FastPack® System when used for the quantitative determination of TSH in human plasma.

The FastPack® Controls are assayed quality control materials for the verification of the accuracy and precision of the FastPack® System when used for the

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quantitative determination of PSA in human serum and plasma, and TSH in human plasma.

3. Special conditions for use statement(s):

None

4. Special instrument requirements:

General laboratory equipment, FastPack® System

# I. Device Description:

The FastPack® TSH Immunoassay is a chemiluminescence assay based on the "sandwich" principle consisting of a biotinylated mouse monoclonal TSH-specific antibody, a mouse monoclonal TSH antibody labeled with alkaline phosphatase, streptavidin-coated paramagnetic particles, chemiluminogenic substrate, and wash buffer.

# J. Substantial Equivalence Information:

1. Predicate device name(s):

Abbott Laboratories IMx Ultrasensitive hTSH II

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

k942566

3. Comparison with predicate:

| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Intended Use | For the in vitro quantitative determination of thyroid-stimulating hormone (TSH) in human plasma. | For the in vitro quantitative measurement of thyroid-stimulating hormone (TSH) in human serum and Heparinized plasma. |
| Assay Methodology | Sandwich immunoassay | Sandwich immunoassay |
| Data Analysis | Internal data reduction via microcomputer | Internal data reduction via microcomputer |
| Detector | Photomultiplier Tube (PMT) | Photomultiplier Tube (PMT) |
| Label | Alkaline Phosphatase | Alkaline Phosphatase |
| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Sample Type | Plasma | Serum, Heparinized Plasma |
| Antibody | Monoclonal/Monoclonal | Polyclonal/Monoclonal |

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| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Solid Phase | Paramagnetic Particles | Latex Microparticles |
| Substrate | ImmunGlow™ (Indoxyl-3-phosphate and lucigenin) | 4-Methylumbelliferyl Phosphate |
| Detection | Chemiluminescence | Fluorescence |
| Instrument Required | FastPack® System | Abbot Laboratories IMx® System |

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

# L. Test Principle:

A mixture of biotinylated TSH-specific antibody and TSH antibody labeled with alkaline phosphatase reacts with TSH from the patient's sample forming a "sandwich" complex in the mixture. Streptavidin-coated paramagnetic particles are added to the reaction mixture. Wash steps remove unbound materials. Chemiluminogenic substrate is added to the bound complex and results in "glow" chemiluminescence measured in the FastPack® System. The amount of "glow" from the bound labeled-antibody is directly proportional to the concentration of TSH in the sample. The concentration is extrapolated from a standard curve generated from calibrators (sold separately) and verified by controls (sold separately).

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

# 1. Analytical performance:

# a. Precision/Reproducibility:

Three patient plasma pools were assayed over 10 days. The assays were run in duplicate on three analyzers using two lots of reagents. Results for precision are summarized below.

| | Pool 1 | | Pool 2 | | Pool 3 | | Pool 4 | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Grand Mean, μIU/mL | 0.53 | | 1.54 | | 12.39 | | 46.30 | |
| | Std. Dev. | %CV | Std. Dev. | %CV | Std. Dev. | %CV | Std. Dev. | %CV |
| Run to Run | 0.055 | 10.3 | 0.110 | 7.4 | 0.64 | 5.2 | 2.3 | 5.1 |
| Instrument to Instrument | 0.013 | 2.5 | 0.010 | 0.5 | 0.14 | 1.1 | 2.2 | 5.0 |
| Lot to Lot | 0.015 | 2.9 | 0.005 | 0.3 | 0.08 | 4.8 | 0.5 | 1.1 |
| Total | 0.057 | 10.8 | 0.15 | 9.7 | 0.93 | 7.5 | 4.4 | 9.5 |

# b. Linearity/assay reportable range:

A plasma sample with roughly $100\mu \mathrm{IU} / \mathrm{mL}$ was diluted with $0\mu \mathrm{IU} / \mathrm{mL}$ diluent to produce samples with 75, 50, 25, and $10\mu \mathrm{IU} / \mathrm{mL}$ TSH. Each of these samples was

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assayed in triplicate. Percent recoveries ranged from 96.1-104.1% of expected. Results are summarized below.

| Sample | Expected Value, μIU/mL | Observed Value, μIU/mL | % Recovery |
| --- | --- | --- | --- |
| TSH 100 | 111.8 | 111.8 | 100 |
| TSH 75 | 83.9 | 80.6 | 96.1 |
| TSH 50 | 55.9 | 58.2 | 104.1 |
| TSH 25 | 28.0 | 28.8 | 103 |
| TSH 10 | 11.2 | 11.8 | 105 |
| Diluent | 0.0 | 0.0 | - |

Observed = 0.9947(Expected); r = 0.9991

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

For the calibrator, a master curve is generated in the factory for each lot of the FastPack reagents. The 6-point master curve is generated using master calibrators referenced to the WHO 2nd IRP 80/558 standard. The master curve information is transferred to the FastPack System through the barcode on the FastPack.

For the control, TSH antigen is procured as a purified powder (>90%). An antigen stock is prepared by adding the purified powder to a Tris buffer containing bovine serum albumin, and sucrose. The intermediate stock is used to prepare the final concentration of TSH in the calibrator/control matrix. The values are assigned using standards (Monobind, Inc.) traceable to the WHO 2nd IRP 80/558 standard.

The calibrator and control stability was tested using five different accelerated stability testing groups each with samples being tested at 30°C and 37°C. Based on the accelerated stability data, twelve month stability at 2-8°C is claimed for the TSH calibrators and controls. Real-time studies will continue to confirm and extend the dating.

d. Detection limit:

Functional sensitivity was determined by measuring twenty-seven plasma samples on three FastPack instruments using two lots of TSH FastPack assayed over a period of one week. The concentration at which assay imprecision was calculated to be 20% CV (by interpolation) is 0.13 μIU/mL.

The analytical sensitivity, defined as the lowest signal that can be distinguished from the zero standard by 2 standard deviations, was assessed by measuring 10 replicates on three FastPack instruments using two reagent lots of the zero level calibrator. The analytical sensitivity was determined to be 0.01 μIU/mL.

The potential for a high dose hook effect was evaluated for this assay by spiking a human serum standard that had been completely depleted of TSH. Spiking ranged from 0

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$\mu \mathrm{IU} / \mathrm{mL}$ to $5000~\mu \mathrm{IU} / \mathrm{mL}$ . No effect was observed at $5000~\mu \mathrm{IU} / \mathrm{mL}$ .

# e. Analytical specificity:

To test the crossreactivity of this device to similar endogenous analytes, plasma samples were spiked with hCG, LH, and FSH at 200000, 500, and $500\mathrm{mIU / mL}$ , respectively, and compared to a non-spiked base pool. No analytes tested significantly cross-reacted in this analysis as the cross-reactivity was shown to be $0.00\%$ for all analytes.

A patient sample was spiked with specific concentrations of potential interfering substances, and the TSH values were obtained using the FastPack® TSH Immunoassay. No interference was found. Results are summarized below.

| | | | Control | Test | |
| --- | --- | --- | --- | --- | --- |
| Heparin Plasma | | mg/dL | [TSH] | [TSH] | |
| [TSH] = normal | | added | μIU/mL | μIU/mL | % Recovery of Ctrl |
| | Bilirubin | 40 | 2.16 | 2.19 | 101% |
| | Hemoglobin | 1,000 | 1.99 | 2.08 | 105% |
| | Triglycerides | 1,000 | 2.14 | 2.12 | 99% |

# f. Assay cut-off: N/A

# 2. Comparison studies:

# a. Method comparison with predicate device:

Clinical samples (n=96 obtained as frozen plasma samples through outside laboratories) were tested using the device and the predicate and compared. Results were determined using linear regression and are summarized below.

Device $= 1.03$ (Predicate) $+0.83$ ; $\mathrm{r} = 0.97$

# b. Matrix comparison:

A heparin plasma pool from four patients was aliquoted into four equal portions which were then spiked with TSH to produce final concentrations of 0.5, 2.5, 5.0, and 20.0 $\mu \mathrm{IU} / \mathrm{mL}$ . These samples as well as the original pool were then assayed for TSH using the FastPack System and the FastPack TSH Immunoassay to determine the percent recoveries of the spiked TSH. Results are summarized below.

| Sample Number | Expected Value, μIU/mL | Observed Value, μIU/mL | % Recovery |
| --- | --- | --- | --- |
| 1 | 1.58 | 1.58 | 100 |
| 2 | 2.08 | 2.07 | 99.8 |
| 3 | 4.08 | 4.37 | 107.2 |
| 4 | 6.58 | 6.97 | 105.9 |
| 5 | 21.58 | 20.93 | 97.0 |

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

4. Clinical cut-off:

5. Expected values/Reference range:

Plasma samples from 211 normal, apparent healthy individuals were obtained from a commercial source and assayed with the FastPack® TSH Immunoassay. The expected normal range for the FastPack® TSH Immunoassay was found to be 0.66-5.45 µIU/mL based on the central 95% of the frequency distribution.

N. Proposed Labeling:

The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.

O. Conclusion:

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

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