BINDAZYME CLQ CIC EIA KIT
Device Facts
| Record ID | K031563 |
|---|---|
| Device Name | BINDAZYME CLQ CIC EIA KIT |
| Applicant | The Binding Site, Ltd. |
| Product Code | DAK · Immunology |
| Decision Date | Sep 10, 2003 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 866.5240 |
| Device Class | Class 2 |
Indications for Use
This assay is designed for the in-vitro measurement of circulating immune complexes (CIC) that bind Clq, measurement on on serum. It is intended for the determination of presence in names patients with various autoimmune and other CICrelated disease, and is used in conjunction with other clinical findings.
Device Story
The BINDAZYME C1q Binding Circulating Immune Complex Enzyme Immunoassay Kit is an in-vitro diagnostic test used to detect circulating immune complexes (CIC) in human serum. The device utilizes an enzyme immunoassay (EIA) principle to measure the presence of CICs that bind to C1q. It is intended for use in clinical laboratory settings by trained laboratory personnel. The output is a measurement of CIC levels, which healthcare providers use alongside other clinical findings to assist in the diagnosis and management of autoimmune and other CIC-related conditions. The test provides quantitative or semi-quantitative data to support clinical decision-making regarding patient immune status.
Clinical Evidence
Bench testing only. Analytical performance included intra-assay (CV 5.5-7.5%) and inter-assay (CV 3.9-13.0%) precision. Linearity demonstrated with R² > 0.99. Limit of detection is 0.1 µg Eq/mL. Method comparison with predicate (n=48) showed 83.3% agreement and R²=0.8082. Normal range established using 200 healthy donors.
Technological Characteristics
Enzyme immunoassay; microtiter plate solid phase coated with human C1q; peroxidase-labeled rabbit anti-human IgG conjugate; TMB substrate; 3M phosphoric acid stop solution. Measures absorbance at 450 nm. Semi-quantitative; results calculated against aggregated human IgG calibrators.
Indications for Use
Indicated for the in vitro measurement of circulating immune complexes (CIC) that bind C1q in human serum for patients with autoimmune or other CIC-related diseases. For prescription use only.
Regulatory Classification
Identification
A complement components immunological test system is a device that consists of the reagents used to measure by immunochemical techniques complement components C1q , C1r , C1s , C2 , C3 , C4 , C5 , C6 , C7 , C8 , and C9 , in serum, other body fluids, and tissues. Complement is a group of serum proteins which destroy infectious agents. Measurements of these proteins aids in the diagnosis of immunologic disorders, especially those associated with deficiencies of complement components.
Related Devices
- K032254 — IBL C1Q-CIC CIA TEST · Ibl GmbH · Aug 29, 2003
- K032796 — IBL C3D-CIC EIA TEST · Ibl GmbH · Jan 13, 2004
- K012576 — CIC-C1Q EIA · American Laboratory Products Co., Ltd. · Jan 29, 2002
Submission Summary (Full Text)
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510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
DEVICE ONLY TEMPLATE
A. 510(k) Number:
k031563
B. Analyte:
Complement C1q CIC (circulating immune complexes)
C. Type of Test:
Semi-quantitative enzyme immunoassay
D. Applicant:
The Binding Site, Ltd.
E. Proprietary and Established Names:
BINDAZYME™ C1q Binding Circulating Immune Complex Enzyme Immunoassay Kit
F. Regulatory Information:
1. Regulation section:
21 CFR 866.5240
Complement Components Immunological Test System
2. Classification:
Class II
3. Product Code:
DAK
Complement C1q, Antigen, Antiserum, Control
4. Panel:
Immunology (82)
G. Intended Use:
1. Intended use(s):
The BINDAZYME™ C1q Binding Circulating Immune Complex Enzyme Immunoassay Kit is designed for the in vitro measurement of circulating immune complexes (CIC) that bind C1q, present in human serum. It is intended for the determination of CIC in serum of patients with various autoimmune and other CIC-related diseases, and is used in conjunction with other clinical findings.
2. Indication(s) for use:
The BINDAZYME™ C1q Binding Circulating Immune Complex Enzyme Immunoassay Kit is designed for the in vitro measurement of circulating immune complexes (CIC) that bind C1q, present in human serum. It is intended for the determination of CIC in serum of patients with various autoimmune and other CIC-related diseases, and is used in conjunction with other clinical findings.
3. Special condition for use statement(s):
For prescription use only
4. Special instrument Requirements:
None given
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# H. Device Description:
The device is an enzyme immunoassay using microtiter plates as the solid phase. The plate wells are coated with human C1q which captures C1q binding immune complexes present in the patient sample. The conjugate is peroxidase labeled antibody to human IgG which uses 3,3'5,5' tetramethylbenzidine (TMB) as substrate. The kit contains 5 levels of calibrators (aggregated human IgG) with concentrations of 100, 33.3, 11.1, 3.7, and 1.23 µg Eq/mL of immune complex. A positive and a negative control are included with the kit. The kit also contains sample diluent, wash buffer concentrate and stop solution.
# I. Substantial Equivalence Information:
1. Predicate device name(s):
ALPCO CIC-C1q Circulating Immune Complexes EIA
2. Predicate K number(s):
k012576
3. Comparison with predicate:
| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Indication for Use | Measurement of circulating immune complexes (CIC) that bind C1q present in human serum. It is intended for the determination of CIC in serum of patients with various autoimmune and other CIC-related disease and is used in conjunction with other clinical findings. | Quantitative determination of circulating immune complexes (CIC) in serum and plasma of patients with various autoimmune and other CIC-related diseases. |
| Methodology | Enzyme immunoassay | Enzyme immunoassay |
| Solid Phase | Microtiter wells coated with human C1q | Microtiter wells coated with human C1q |
| Differences | | |
| Item | Device | Predicate |
| Sample Matrix | Serum (fasting 12 hours) | Serum/plasma (fasting 12 hours) |
| Cut-offs | Neg. < 4.4 µg Eq/mL
Equiv. 4.4-10.8
Pos. > 10.8 | Neg. <3.2 µg Eq/mL
Equiv. 3.2-5.0
Pos. > 5.0 |
| Interfering substances | Rheumatoid Factor | None listed |
| Calibrators | Aggregated human IgG 100, 33.3, 11.1, 3.7 and 1.23 µg Eq/mL | Aggregated human IgG 50, 20, 10, 4, and 1 µg Eq/mL |
| Controls | Positive - aggregated human IgG | High and Low levels containing lot specific |
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| | Negative - diluted human sera | amounts of aggregated human IgG |
| --- | --- | --- |
| Conjugate | Peroxidase labeled antibody to human IgG | Protein A conjugated to alkaline phosphatase |
| Substrate | TMB | pNPP |
| Stop Solution | 3M phosphoric acid | 1N sodium hydroxide |
| Total Incubation Time | 90 minutes | 125 minutes |
J. Standard/Guidance Document Referenced (if applicable):
None
K. Test Principle:
Microwells are pre-coated with purified human C1q. The calibrators, controls and diluted patient samples are added to the wells and C1q binding immune complexes are bound by the C1q during the first incubation. After washing the wells to remove all unbound proteins, purified peroxidase labeled rabbit antihuman IgG (γ chain specific) conjugate is added. The conjugate binds to the captured immune complex and the excess unbound conjugate is removed by a further wash step. The bound conjugate is visualized with TMB substrate which gives a blue reaction product, the intensity of which is proportional to the concentration of C1q binding CIC in the sample. Phosphoric acid is added to each well to stop the reaction. This produces a yellow end point color, which is measured at 450 nm. The concentration of CIC in the sample is read from the calibration curve and results are expressed as heat aggregated human IgG equivalents per mL (μg Eq/mL).
L. Performance Characteristics (if/when applicable):
1. Analytical performance:
a. Precision/Reproducibility:
Inter-assay
The inter-assay precision was measured using three samples within the measuring range of the calibration curve. The studies compare the mean duplicate result of each of the three samples across three different kit batches. CV's ranged from 3.9-13.0%.
Intra-assay
The intra-assay precision was measured using three samples within the measuring range of the calibration curve. The studies show the CV's within a single plate based on 16 individual results for each of the three samples. CV's ranged from 5.5-7.5%.
b. Linearity/assay reportable range:
Linearity (dilution recovery)
Studies were performed to demonstrate that all samples accurately dilute across the standard curve range and correlate to their predicted values based on dilution. Samples were diluted to 1:100 and double dilutions were made from this. The values were then plotted and a correlation coefficient produced. One high sample (69.7 μg Eq/mL) and 2 moderate level samples (28.5 and 28.7 μg Eq/mL) were serially diluted. For the high sample regression analysis yielded y =
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1.0047x - 1.6536, R² = 0.9977. The two moderate samples showed y = 1.0091x - 0.4153, R² = 0.996 and y = 1.0083x - 0.3005, R² = 0.999, respectively.
c. Traceability (controls, calibrators, or method):
N/A
d. Detection limit:
The limit of detection was determined as the mean concentration + 2SD given by 20 determinations of the sample diluent. A value of 0.1 µg Eq/mL was obtained.
e. Analytical specificity:
The studies compared a normal and high positive sera spiked with known amounts of specific serum factors. The interfering substances were tested at elevated levels to mimic high contamination. No interference was observed with free or conjugated bilirubin, hemoglobin, or chyle. Rheumatoid Factor (RF) did cause interference at a level of 500 IU/mL and is reported in the package insert.
f. Assay cut-off:
See Clinical cut-off
2. Comparison studies:
a. Method comparison with predicate device:
Forty eight samples including 29 normal serum and 19 clinical (12 SLE and 7 other disease positive) were tested using the new and the predicate device. The overall agreement between the two assays was 83.3%. Linear regression analysis yielded y = 0.862x - 3.14, R² = 0.8082.
b. Matrix comparison:
N/A - for use with serum only.
3. Clinical studies:
a. Clinical sensitivity:
Not provided
b. Clinical specificity:
Not provided
c. Other clinical supportive data (when a and b are not applicable):
4. Clinical cut-off:
The normal range (cut-off for negative) was assessed using 200 normal adult blood donor samples (112 males and 88 females). C1q-CIC are found sporadically in the normal population as a result of infection, and can also be elevated after eating. To arrive at a logical cut-off for the 'true normal', the elevated samples have been eliminated by three iterative cycles. Each cycle involves calculating the mean and SD and removing any samples with values greater than the mean +3SD. After two further cycles, a total of 19 samples were removed and the resulting mean +2SD gave a value for the cut-off of 4.4 µg Eq/mL. The same iterative procedure was used in the predicate device cut-off determination. An equivocal range has been set between 4.4 and 10.8 µg
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Eq/mL with positive being >10.8 µg Eq/mL. Using this cut-off, 95% of the normal samples were negative.
5. Expected values/Reference range:
The expected value in the normal population should be negative. However, up to 5-6% of normal donors can have levels of C1q-CIC above the cut-off.
M. Conclusion:
The Binding Site BINDAZYME™ C1q Binding Circulating Immune Complex Enzyme Immunoassay Kit is substantially equivalent to other devices regulated under 21 CFR §866.5240, product code DAK.
