Aptiva APS IgG Reagent; Aptiva APS IgM Reagent
Device Facts
| Record ID | K223093 |
|---|---|
| Device Name | Aptiva APS IgG Reagent; Aptiva APS IgM Reagent |
| Applicant | Inova Diagnostics, Inc. |
| Product Code | MID · Immunology |
| Decision Date | Dec 17, 2024 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 866.5660 |
| Device Class | Class 2 |
Intended Use
The Aptiva APS IgG Reagent is an immunoassay utilizing particle-based multi-analyte technology for the semiquantitative determination of anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aß2GPI) IgG autoantibodies in human serum as an aid in the diagnosis of primary antiphospholipid syndrome (APS), when used in conjunction with other laboratory findings. The Aptiva APS IgG Reagent is intended for use with the Aptiva System. The Aptiva APS IgM Reagent is an immunoassay utilizing particle-based multi-analyte technology for the semiquantitative determination of anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aß2GPI) IgM autoantibodies in human serum as an aid in the diagnosis of primary and secondary antiphospholipid syndrome (APS), when used in conjunction with other laboratory findings. The Aptiva APS IgM Reagent is intended for use with the Aptiva System.
Device Story
Aptiva APS IgG/IgM reagents are particle-based multi-analyte (PMAT) immunoassays for automated, random-access analysis on the Aptiva System. Input: human serum samples. Operation: paramagnetic microparticles coated with cardiolipin and beta-2 glycoprotein 1 antigens are rehydrated and incubated with diluted sample; after washing, phycoerythrin-conjugated anti-human IgG or IgM antibodies are added. The system uses an optical module to generate images, identifying unique particle populations and measuring median fluorescent intensity (MFI). Output: semiquantitative results (FLU) calculated via lot-specific master curves stored on RFID. Used in clinical laboratories by trained personnel. Results aid clinicians in diagnosing APS by identifying specific autoantibodies. Benefits include automated, high-throughput, multi-analyte testing compared to manual ELISA methods.
Clinical Evidence
Clinical validation included 526 samples for IgG (122 APS, 404 controls) and 689 samples for IgM (291 APS, 398 controls). For IgG: aCL sensitivity 54.1%, specificity 99.5%; aβ2GPI sensitivity 53.3%, specificity 99.0%. For IgM: aCL sensitivity 27.5%, specificity 97.5%; aβ2GPI sensitivity 24.7%, specificity 98.5%.
Technological Characteristics
Particle-based multi-analyte technology (PMAT) using paramagnetic microparticles. Reagents include cardiolipin and beta-2 glycoprotein 1 antigens, goat anti-human IgG/IgM tracer antibodies labeled with phycoerythrin. Fully automated, random-access analyzer (Aptiva System) with optical module. Connectivity via RFID-tagged reagent cartridges. Software uses 4-parameter logistic (4PL) curve fitting for quantitation.
Indications for Use
Indicated for semiquantitative determination of anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aß2GPI) IgG/IgM autoantibodies in human serum to aid in the diagnosis of primary and secondary antiphospholipid syndrome (APS) in conjunction with other clinical/laboratory findings.
Regulatory Classification
Identification
A multiple autoantibodies immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the autoantibodies (antibodies produced against the body's own tissues) in serum and other body fluids. Measurement of multiple autoantibodies aids in the diagnosis of autoimmune disorders (disease produced when the body's own tissues are injured by autoantibodies).
Predicate Devices
- HemosIL™ AcuStar Anti-Cardiolipin IgG (K092181)
- QUANTA Lite™ Beta 2GP1 IgG ELISA (K970551)
- HemosIL™ AcuStar Anti-Cardiolipin IgM (K092181)
- HemosIL™ AcuStar Anti-ß2 Glycoprotein-I IgM (K091556)
Related Devices
- K243979 — Aptiva APS IgA Reagent · Inova Diagnostics, Inc. · Feb 6, 2026
- K091845 — CARDIOLIPIN AUTOANTIBODY IMMUNOLOGICAL TEST SYSTEM · Phadia US, Inc. · Jun 7, 2010
Submission Summary (Full Text)
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FDA U.S. FOOD & DRUG ADMINISTRATION
# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY
ASSAY ONLY
## I Background Information:
A 510(k) Number
K223093
B Applicant
INOVA Diagnostics, Inc.
C Proprietary and Established Names
Aptiva APS IgG Reagent
Aptiva APS IgM Reagent
D Regulatory Information
| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| MID | Class II | 21 CFR 866.5660 – Multiple | IM – Immunology |
| MSV | | Autoantibodies Immunological Test System | |
## II Submission/Device Overview:
A Purpose for Submission:
New Device
B Measurand:
Aptiva APS IgG Reagent
Anti-cardiolipin IgG autoantibodies (aCL IgG)
Anti-beta 2 glycoprotein 1 IgG autoantibodies (aβ2GPI IgG)
Aptiva APS IgM Reagent
Anti-cardiolipin IgM autoantibodies (aCL IgM)
Anti-beta 2 glycoprotein 1 IgM autoantibodies (aβ2GPI IgM)
Food and Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993-0002
www.fda.gov
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C Type of Test:
Semi quantitative, Particle-based multi-analyte assay
III Intended Use/Indications for Use:
A Intended Use(s):
See Indications for Use below.
B Indication(s) for Use:
Aptiva APS IgG Reagent
The Aptiva APS IgG Reagent is an immunoassay utilizing particle-based multi-analyte technology for the semi-quantitative determination of anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aβ2GPI) IgG autoantibodies in human serum as an aid in the diagnosis of primary and secondary antiphospholipid syndrome (APS), when used in conjunction with other clinical and laboratory findings.
The Aptiva APS IgG Reagent is intended for use with the Aptiva System.
Aptiva APS IgM Reagent
The Aptiva APS IgM Reagent is an immunoassay utilizing particle-based multi-analyte technology for the semi-quantitative determination of anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aβ2GPI) IgM autoantibodies in human serum as an aid in the diagnosis of primary and secondary antiphospholipid syndrome (APS), when used in conjunction with other clinical and laboratory findings.
The Aptiva APS IgM Reagent is intended for use with the Aptiva System.
C Special Conditions for Use Statement(s):
Rx - For Prescription Use Only
D Special Instrument Requirements:
Inova Diagnostics Aptiva System (K193604)
IV Device/System Characteristics:
A Device Description:
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Aptiva APS IgG Reagent and Aptiva APS IgM Reagent utilize particle-based multi-analyte technology (PMAT) in a cartridge format. Both assays are run on Inova Diagnostics Aptiva System.
The **Aptiva APS IgG Reagent** contains one cartridge with the following reagents for 200 determinations:
- APS IgG Beads (1×0.5 mL): Paramagnetic beads coated with native Cardiolipin (CL) plus β2GPI antigens, native β2GPI antigen, AffiniPure goat polyclonal anti-human IgG, and stabilizer
- Assay Buffer (1×17 mL): Containing protein stabilizers and preservatives
- PE Tracer IgG (1×17 mL): Phycoerythrin (PE) labeled goat anti-human IgG antibody with stabilizer and preservative
- Rehydration Buffer (1×6.5 mL): Containing protein stabilizer and preservative
## Materials Required but Not Provided
- Aptiva APS IgG Calibrators: 3 Calibrators (2×0.3mL/each) of human antibodies, each contains human aCL IgG and aβ2GPI IgG in stabilizers and preservatives;
- Aptiva APS IgG Controls: 2 Controls (2×0.5 mL/each) of human antibodies, each contain human aCL IgG and aβ2GPI IgG in stabilizers and preservatives
The **Aptiva APS IgM Reagent** kit contains one cartridge with the following reagents for 200 determinations:
- APS IgM Beads (1×0.5 mL): Paramagnetic beads coated with native Cardiolipin (CL) plus β2GPI antigens, native β2GPI antigen, AffiniPure goat polyclonal anti-human IgM, and stabilizer
- Assay Buffer (1×17 mL): Containing protein stabilizers and preservatives
- PE Tracer IgM (1×17 mL): PE labeled goat anti-human IgM antibody with stabilizer and preservative
- Rehydration Buffer (1×6.5 mL): Containing protein stabilizer and preservative
## Materials Required but Not Provided
- Aptiva APS IgM Calibrators: 3 Calibrators (2×0.3mL/each) of human antibodies, each contains human aCL IgM and aβ2GPI IgM in stabilizers and preservatives
- Aptiva APS IgM Controls: 2 Controls (2×0.5 mL/each) of human antibodies, each contains human aCL IgM and aβ2GPI IgM in stabilizers and preservatives
## B Principle of Operation:
Both the Aptiva APS IgG Reagent and Aptiva APS IgM Reagent utilize particle based multi-analyte technology (PMAT) in a cartridge format. Both the Aptiva APS IgG Reagent and the
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Aptiva APS IgM Reagent contain two different populations of particles: one particle population coated with cardiolipin along with human purified $\beta 2\mathrm{GPI}$ and another particle population coated with only human purified $\beta 2\mathrm{GPI}$ antigen. The two analyte microparticles, along with the control microparticle, are stored in the reagent cartridge.
The Aptiva System dilutes the sample 1:8, then combines an aliquot of diluted sample, and reagent into a cuvette. After incubation at $37^{\circ}\mathrm{C}$ and followed with a wash cycle, conjugated anti-human IgG or IgM antibodies are added to the particles. Following the incubation of this mixture at $37^{\circ}\mathrm{C}$, excess conjugate is removed in another wash cycle, and the particles are re-suspended in system fluid. Multiple images are generated by the system to identify and count the two unique analyte particles, as well as determine the amount of conjugate on each particle. A third particle, coated with goat anti-human IgG or IgM antibodies, is present in the reagent as a control to flag low concentrations of IgG or IgM in the sample as an assay verification step. The median fluorescent intensity (MFI) for each analyte is proportional to the concentration of conjugate bound to human IgG or IgM, which is proportional to the concentration of IgG or IgM antibodies bound to the corresponding particle population. The system uses the MFI from at least 50 particles of each population. The identity of the particles is determined by the unique signature of the particles.
Each analyte in the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent is assigned a predefined lot specific master curve. The analyte specific master curve is stored on the reagent cartridge radio frequency identification (RFID) label. Based on results obtained by running calibrators (supplied separately), the system creates individual working curves. Working curves are used by the software to calculate Fluorescent Light Units (FLU) for each analyte from the MFI values obtained for each sample.
V Substantial Equivalence Information:
A Predicate Device Name(s):
For Aptiva APS IgG Reagent:
HemosIL AcuStar Cardiolipin IgG
QUANTA Lite $\beta 2\mathrm{GPI}$ IgG ELISA
For Aptiva APS IgM Reagent:
HemosIL AcuStar Cardiolipin IgM
HemoIL AcuStar anti-$\beta 2$ Glycoprotein-I IgM
B Predicate 510(k) Number(s):
K092181 - HemosIL AcuStar Cardiolipin IgG; HemosIL AcuStar Cardiolipin IgM
K970551 - QUANTA Lite $\beta 2\mathrm{GPI}$ IgG ELISA
K091556 - HemosIL AcuStar anti-$\beta 2$ Glycoprotein-I IgM
C Comparison with Predicate(s):
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Aptiva APS IgG Reagent
| Device & Predicate Device(s): | K223093
New Device | K092181
Predicate | K970551
Predicate |
| --- | --- | --- | --- |
| Device Trade Name | Aptiva APS IgG Reagent | HemosIL AcuStar Cardiolipin IgG | QUANTA Lite β2GPI IgG ELISA |
| **General Device Characteristic Similarities** | | | |
| Intended Use/Indications for Use | The Aptiva APS IgG Reagent is an immunoassay utilizing particle-based multi-analyte technology for the semi-quantitative determination of anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aβ2GPI) IgG autoantibodies in human serum as an aid in the diagnosis of primary and secondary antiphospholipid syndrome (APS), when used in conjunction with other laboratory findings. The Aptiva APS IgG Reagent is intended for use with the Aptiva System. | Fully automated chemiluminescent immunoassay for the semi-quantitative measurement of anti-cardiolipin (aCL) IgG antibodies in human citrate plasma and serum on the BIO-FLASH instrument as an aid in the diagnosis of thrombotic disorders related to primary and secondary antiphospholipid syndrome (APS), when used in conjunction with other laboratory and clinical findings. | A semi-quantitative enzyme linked immunoassay for detecting IgG class autoantibody to β2 glycoprotein I (β2 GPI) for use as an aid in the diagnosis of certain autoimmune disease thrombotic disorders, such as those secondary to systemic lupus erythematosus (SLE) or other lupus-like thrombotic diseases. |
| Antigen | Bovine cardiolipin antigen | Same | N/A |
| | Purified human β2GPI | N/A | Same |
| Quality Control | 2 controls
(sold separately) | Same
(sold separately) | Same
(included in the kit) |
| **General Device Characteristic Differences** | | | |
| Solid Phase | Paramagnetic microparticles | Same | 96-well polystyrene plate |
| Assay Format | Fluorescent immunoassay | Chemiluminescent immunoassay | Enzyme-linked immunosorbent assay |
| Instrumentation | INOVA Aptiva System | BIO-FLASH Instrument | Manual, ELISA reader |
| Sample Type | Human Serum | Human serum and citrated plasma | Human serum |
| Conjugate | Phycoerythrin conjugated polyclonal anti-human IgG antibody | Isoluminol conjugated monoclonal anti-human IgG antibody | Anti-human IgG horseradish peroxidase (HRP) |
| Units | Fluorescent light units (FLU) | Chemiluminescent Units | Standard β2GPI IgG Units (SGU) |
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# Aptiva APS IgM Reagent
| Device & Predicate Device(s): | K223095
New Device | K092181
Predicate | K091556
Predicate |
| --- | --- | --- | --- |
| Device Trade Name | Aptiva APS IgM Reagent | HemosIL AcuStar Cardiolipin IgM | HemosIL AcuStar anti-β2 Glycoprotein-I IgM |
| General Device Characteristic Similarities | | | |
| Intended Use/Indications for Use | The Aptiva APS IgM Reagent is an immunoassay utilizing particle-based multi-analyte technology for the semi-quantitative determination of anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aβ2GPI) IgM autoantibodies in human serum as an aid in the diagnosis of primary and secondary antiphospholipid syndrome (APS), when used in conjunction with other laboratory findings.
The Aptiva APS IgM Reagent is intended for use with the Aptiva System. | Fully automated chemiluminescent assay for the semi-quantitative measurement of anti-cardiolipin (aCL) IgM antibodies in human citrated plasma and serum on the BIO-FLASH instrument, as an aid in the diagnosis of thrombotic disorders related to primary and secondary antiphospholipid syndrome (APS), when used in conjunction with other laboratory and clinical findings. | Fully automated chemiluminescent immunoassay for the semi-quantitative measurement of anti-β2 glycoprotein-I (anti-β2GPI) IgM antibodies in human citrated plasma and serum on the BIO-FLASH instrument as an aid in the diagnosis of thrombotic disorders related to primary and secondary antiphospholipid syndrome (APS), when used in conjunction with other laboratory and clinical findings. |
| Solid phase | Paramagnetic microparticles | Same | Same |
| Antigen | Bovine cardiolipin antigen | Same | N/A |
| | Purified human β2GPI | N/A | Same |
| Quality Control | 2 control levels (sold separately) | Same | Same |
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| General Device Characteristic Differences | | | |
| --- | --- | --- | --- |
| Sample Type | Human serum | Human serum and citrated plasma | |
| Assay Format | Fluorescent immunoassay | Chemiluminescent immunoassay | |
| Instrumentation | INOVA Aptiva System | BIO-FLASH instrument | |
| Conjugate | Phycoerythrin conjugated polyclonal anti-human IgM antibody | Isoluminol conjugated monoclonal anti-human IgM antibody | |
| Units | Fluorescent light units | Chemiluminescent units | |
| Result Interpretation | Negative: <5.00 FLU
Positive: ≥5.00 FLU | Negative: <20 U/mL
Positive: ≥20 U/mL | |
| Analytical Measuring Interval | 0.1–114.68 FLU (aCL IgM) | 1.0 – 774.0 U/mL | |
| | 0.1– 95.86 FLU (aβ2GPI IgM) | | 1.1– 841 U/mL |
| Calibration | Lot specific Master Curve + 3 calibrators (sold separately) | Two calibrator levels (included in test kit) | |
VI Standards/Guidance Documents Referenced:
The following Clinical and Laboratory Standards Institute (CLSI) guidelines were used:
- CLSI EP05-A3: Evaluation of Precision of Quantitative Measurement Procedures, Approved Guideline – Third Edition.
- CLSI EP06-Ed2: Evaluation of the Linearity of Quantitative Measurement Procedures – Second Edition
- CLSI EP07-A3: Interference Testing in Clinical Chemistry – Third Edition.
- CLSI EP12-A2: User Protocol for Evaluation of Qualitative Test Performance – Second Edition.
- CLSI EP17-A2: Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures, Approved Guideline – Second Edition.
- CLSI EP25-A: Evaluation of Stability of In Vitro Diagnostic Reagents, Approved Guideline
- CLSI EP28-A3c: Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory, Approved Guideline – Third Edition.
- CLSI EP37: Supplemental Tables for Interference Testing in Clinical Chemistry
- CLSI EP39: A Hierarchical Approach to Selecting Surrogate Samples for the Evaluation of In Vitro Medical Laboratory Tests
VII Performance Characteristics (if/when applicable):
A Analytical Performance:
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# 1. Precision/Reproducibility:
Precision and reproducibility of the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent were evaluated in accordance with the CLSI guideline EP05-A3.
Within-Laboratory Precision:
Within-lab precision of the Aptiva APS IgG reagent was performed with by testing seven serum samples containing various concentrations of aCL IgG, a $\beta$ 2GPI IgG, aCL IgM and a $\beta$ 2GPI IgM autoantibodies. All samples were run in duplicate, twice a day, for 20 days using single lot of reagents on single instrument. Data was analyzed for repeatability (within-run), between-run, between-day and within-laboratory precision. Results are summarized below.
Aptiva APS IgG Reagent
| aCL IgG | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Repeatability | | Between-Run | | Between-Day | | Within-Laboratory | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| 1 | 80 | 2.33 | 0.13 | 5.5 | 0.08 | 3.3 | 0.10 | 4.3 | 0.18 | 7.8 |
| 2 | 80 | 5.64 | 0.29 | 5.1 | 0.10 | 1.8 | 0.28 | 5.0 | 0.42 | 7.4 |
| 3 | 80 | 8.77 | 0.37 | 4.2 | 0.32 | 3.7 | 0.00 | 0.0 | 0.49 | 5.6 |
| 4 | 80 | 26.15 | 1.41 | 5.4 | 0.00 | 0.0 | 1.42 | 5.4 | 2.00 | 7.6 |
| 5 | 80 | 66.29 | 2.53 | 3.8 | 2.22 | 3.4 | 2.71 | 4.1 | 4.32 | 6.5 |
| 6 | 80 | 201.45 | 7.94 | 3.9 | 5.58 | 2.8 | 10.65 | 5.3 | 14.40 | 7.2 |
| 7 | 80 | 265.15 | 11.06 | 4.2 | 10.94 | 4.1 | 19.96 | 7.5 | 25.30 | 9.5 |
| aβ2GPI IgG | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Repeatability | | Between-Run | | Between-Day | | Within-Laboratory | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| 1 | 80 | 2.04 | 0.15 | 7.3 | 0.04 | 1.9 | 0.18 | 9.0 | 0.24 | 11.7 |
| 2 | 80 | 5.12 | 0.29 | 5.7 | 0.22 | 4.4 | 0.00 | 0.0 | 0.37 | 7.1 |
| 3 | 80 | 9.39 | 0.50 | 5.3 | 0.29 | 3.1 | 0.89 | 9.5 | 1.06 | 11.3 |
| 4 | 80 | 24.55 | 1.22 | 5.0 | 0.22 | 0.9 | 1.69 | 6.9 | 2.10 | 8.5 |
| 5 | 80 | 53.51 | 2.11 | 3.9 | 2.08 | 3.9 | 2.22 | 4.1 | 3.70 | 6.9 |
| 6 | 80 | 170.02 | 6.40 | 3.8 | 5.05 | 3.0 | 7.83 | 4.6 | 11.30 | 6.6 |
| 7 | 80 | 212.10 | 8.19 | 3.9 | 6.60 | 3.1 | 14.44 | 6.8 | 17.86 | 8.4 |
Aptiva APS IgM Reagent
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| aCL IgM | | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Repeatability | | Between-Run | | Between-Day | | Within-Laboratory | | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV | |
| 1 | 80 | 2.93 | 0.12 | 4.1 | 0.06 | 2.1 | 0.25 | 8.5 | 0.28 | 9.7 | |
| 2 | 80 | 5.54 | 0.15 | 2.8 | 0.10 | 1.9 | 0.20 | 3.6 | 0.27 | 4.9 | |
| 3 | 80 | 10.67 | 0.34 | 3.2 | 0.14 | 1.3 | 0.50 | 4.7 | 0.62 | 5.8 | |
| 4 | 80 | 21.94 | 0.59 | 2.7 | 0.55 | 2.5 | 0.51 | 2.3 | 0.95 | 4.3 | |
| 5 | 80 | 56.16 | 1.30 | 2.3 | 0.47 | 0.8 | 3.07 | 5.5 | 3.36 | 6.0 | |
| 6 | 80 | 73.51 | 2.25 | 3.1 | 1.23 | 1.7 | 3.06 | 4.2 | 3.99 | 5.4 | |
| 7 | 80 | 116.09 | 2.62 | 2.3 | 2.55 | 2.2 | 5.90 | 5.1 | 6.94 | 6.0 | |
| aβ2GPI IgM | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Repeatability | | Between-Run | | Between-Day | | Within-Laboratory | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| 1 | 80 | 2.47 | 0.10 | 3.9 | 0.07 | 2.9 | 0.22 | 9.0 | 0.25 | 10.2 |
| 2 | 80 | 5.39 | 0.13 | 2.5 | 0.27 | 5.0 | 0.22 | 4.1 | 0.38 | 7.0 |
| 3 | 80 | 8.75 | 0.28 | 3.2 | 0.19 | 2.1 | 0.38 | 4.4 | 0.51 | 5.8 |
| 4 | 80 | 27.26 | 1.23 | 4.5 | 0.51 | 1.9 | 1.37 | 5.0 | 1.91 | 7.0 |
| 5 | 80 | 46.00 | 1.22 | 2.7 | 0.74 | 1.6 | 2.29 | 5.0 | 2.70 | 5.9 |
| 6 | 80 | 63.00 | 2.10 | 3.3 | 0.63 | 1.0 | 2.70 | 4.3 | 3.48 | 5.5 |
| 7 | 80 | 93.18 | 2.97 | 3.2 | 2.03 | 2.2 | 4.59 | 4.9 | 5.83 | 6.3 |
## Lot-to-Lot Imprecision:
The lot-to-lot imprecision of the Aptiva APS IgG Reagent and Aptiva APS IgM Reagent was evaluated by testing seven serum samples for aCL IgG and a $\beta 2\mathrm{GPI}$ IgG with three lots of the Aptiva APS IgG Reagent and six serum samples for aCL IgM and a $\beta 2\mathrm{GPI}$ IgM with three lots of the Aptiva APS IgM Reagent. Samples were tested in replicates of five, once a day, for five days using one instrument to generate a total of 75 data points for each sample. The results are summarized in the tables below.
## Aptiva APS IgG Reagent
| aCL IgG | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Within-Day | | Between-Day | | Between-Lot | | Total | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| 1 | 75 | 1.61 | 0.08 | 5.2 | 0.07 | 4.4 | 0.12 | 7.2 | 0.16 | 9.9 |
| 2 | 75 | 4.16 | 0.21 | 5.0 | 0.18 | 4.3 | 0.19 | 4.6 | 0.34 | 8.1 |
| 3 | 75 | 19.71 | 0.98 | 5.0 | 0.99 | 5.0 | 2.17 | 11.0 | 2.58 | 13.1 |
| 4 | 75 | 51.11 | 2.67 | 5.2 | 1.63 | 3.2 | 6.06 | 11.9 | 6.82 | 13.3 |
| 5 | 75 | 124.49 | 5.93 | 4.8 | 5.92 | 4.8 | 0.00 | 0.0 | 8.37 | 6.7 |
| 6 | 75 | 168.77 | 7.11 | 4.2 | 8.61 | 5.1 | 0.00 | 0.0 | 11.17 | 6.6 |
| 7 | 75 | 285.27 | 10.73 | 3.8 | 5.73 | 2.0 | 11.38 | 4.0 | 16.66 | 5.8 |
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| aβ2GPI IgG | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Within-Day | | Between-Day | | Between-Lot | | Total | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| 1 | 75 | 1.97 | 0.10 | 5.0 | 0.13 | 6.7 | 0.03 | 1.7 | 0.17 | 8.5 |
| 2 | 75 | 4.94 | 0.26 | 5.3 | 0.35 | 7.2 | 0.40 | 8.2 | 0.60 | 12.1 |
| 3 | 75 | 23.39 | 1.08 | 4.6 | 1.24 | 5.3 | 1.10 | 4.7 | 1.98 | 8.5 |
| 4 | 75 | 58.42 | 3.18 | 5.5 | 2.47 | 4.2 | 3.87 | 6.6 | 5.59 | 9.6 |
| 5 | 75 | 100.56 | 5.55 | 5.5 | 6.40 | 6.4 | 5.21 | 5.2 | 9.94 | 9.9 |
| 6 | 75 | 144.20 | 6.89 | 4.8 | 9.57 | 6.6 | 10.69 | 7.4 | 15.92 | 11.0 |
| 7 | 75 | 213.10 | 8.78 | 4.1 | 5.46 | 2.6 | 21.18 | 9.9 | 23.57 | 11.1 |
## Aptiva APS IgM Reagent
| aCL IgM | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Within-Day | | Between-Day | | Between-Lot | | Total | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| 1 | 75 | 2.07 | 0.07 | 3.3 | 0.10 | 4.9 | 0.03 | 1.7 | 0.13 | 6.1 |
| 2 | 75 | 4.39 | 0.12 | 2.8 | 0.19 | 4.3 | 0.20 | 4.6 | 0.30 | 6.9 |
| 3 | 75 | 5.25 | 0.15 | 2.9 | 0.24 | 4.5 | 0.24 | 4.5 | 0.36 | 6.9 |
| 4 | 75 | 31.61 | 0.83 | 2.6 | 0.85 | 2.7 | 2.16 | 6.8 | 2.46 | 7.8 |
| 5 | 75 | 50.07 | 1.54 | 3.1 | 1.89 | 3.8 | 5.18 | 10.3 | 5.72 | 11.4 |
| 6 | 75 | 88.20 | 3.24 | 3.7 | 3.80 | 4.3 | 8.10 | 9.2 | 9.51 | 10.8 |
| aβ2GPI IgM | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Within-Day | | Between-Day | | Between-Lot | | Total | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| 1 | 75 | 1.57 | 0.05 | 3.3 | 0.09 | 5.6 | 0.06 | 4.0 | 0.12 | 7.6 |
| 2 | 75 | 4.62 | 0.15 | 3.2 | 0.25 | 5.4 | 0.15 | 3.3 | 0.33 | 7.0 |
| 3 | 75 | 5.73 | 0.20 | 3.5 | 0.28 | 4.8 | 0.00 | 0.0 | 0.34 | 6.0 |
| 4 | 75 | 24.76 | 0.61 | 2.5 | 0.68 | 2.7 | 1.86 | 7.5 | 2.07 | 8.4 |
| 5 | 75 | 54.40 | 1.63 | 3.0 | 2.45 | 4.5 | 4.54 | 8.3 | 5.41 | 9.9 |
| 6 | 75 | 80.53 | 2.52 | 3.1 | 3.27 | 4.1 | 7.35 | 9.1 | 8.43 | 10.5 |
## Site-to-Site Precision (Reproducibility):
The reproducibility of the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent was conducted at three different sites using seven serum samples for aCL IgG and aβ2GPI IgG and six serum samples for aCL IgM and aβ2GPI IgM. Samples were tested in replicates of five, once a day, for five days using one reagent lot to generate a total of 75 replicates per sample. The results are summarized below.
## Aptiva APS IgG Reagent
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| aCL IgG | | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Within-Day | | Between-Day | | Between-Site | | Total | | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV | |
| 1 | 75 | 1.97 | 0.10 | 5.2 | 0.04 | 2.3 | 0.12 | 6.0 | 0.16 | 8.3 | |
| 2 | 75 | 5.60 | 0.33 | 5.9 | 0.20 | 3.6 | 0.13 | 2.3 | 0.41 | 7.2 | |
| 3 | 75 | 25.24 | 1.35 | 5.3 | 1.06 | 4.2 | 0.49 | 1.9 | 1.78 | 7.1 | |
| 4 | 75 | 53.83 | 2.46 | 4.6 | 1.48 | 2.7 | 1.40 | 2.6 | 3.19 | 5.9 | |
| 5 | 75 | 123.94 | 6.00 | 4.8 | 2.43 | 1.0 | 0.00 | 0.0 | 6.48 | 5.2 | |
| 6 | 75 | 164.49 | 9.10 | 5.5 | 5.26 | 3.2 | 2.78 | 1.7 | 10.87 | 6.6 | |
| 7 | 75 | 279.39 | 14.03 | 5.0 | 5.79 | 2.1 | 20.98 | 7.5 | 25.89 | 9.3 | |
| aβ2GPI IgG | | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Within-Day | | Between-Day | | Between-Site | | Total | | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV | |
| 1 | 75 | 1.99 | 0.11 | 5.7 | 0.08 | 4.0 | 0.14 | 7.1 | 0.20 | 10.0 | |
| 2 | 75 | 5.26 | 0.24 | 4.6 | 0.20 | 3.8 | 0.19 | 3.6 | 0.36 | 6.9 | |
| 3 | 75 | 23.58 | 1.08 | 4.6 | 1.18 | 5.0 | 0.96 | 4.1 | 1.87 | 7.9 | |
| 4 | 75 | 52.83 | 2.49 | 4.7 | 1.76 | 3.3 | 1.47 | 2.8 | 3.38 | 6.4 | |
| 5 | 75 | 138.12 | 8.47 | 6.1 | 4.03 | 2.9 | 7.36 | 5.3 | 11.92 | 8.6 | |
| 6 | 75 | 161.78 | 6.16 | 3.8 | 4.09 | 2.5 | 10.78 | 6.7 | 13.07 | 8.1 | |
| 7 | 75 | 217.27 | 9.54 | 4.4 | 4.86 | 2.2 | 12.35 | 5.7 | 16.35 | 7.5 | |
## Aptiva APS IgM Reagent
| aCL IgM | | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Within-Day | | Between-Day | | Between-Site | | Total | | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV | |
| 1 | 75 | 2.16 | 0.10 | 4.6 | 0.09 | 4.3 | 0.05 | 2.2 | 0.14 | 6.7 | |
| 2 | 75 | 4.56 | 0.16 | 3.4 | 0.19 | 4.1 | 0.04 | 0.8 | 0.24 | 5.4 | |
| 3 | 75 | 6.68 | 0.28 | 4.1 | 0.19 | 2.8 | 0.33 | 5.0 | 0.47 | 7.1 | |
| 4 | 75 | 40.83 | 1.47 | 3.6 | 1.33 | 3.3 | 3.56 | 8.7 | 4.07 | 10.0 | |
| 5 | 75 | 57.09 | 2.30 | 4.0 | 1.61 | 2.8 | 4.83 | 8.5 | 5.59 | 9.8 | |
| 6 | 75 | 92.71 | 4.27 | 4.6 | 2.36 | 2.5 | 8.24 | 8.9 | 9.58 | 10.3 | |
| aβ2GPI IgM | | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Sample | N | Mean (FLU) | Within-Day | | Between-Day | | Between-Site | | Total | | |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV | |
| 1 | 75 | 1.56 | 0.06 | 3.7 | 0.06 | 3.9 | 0.04 | 2.3 | 0.09 | 5.9 | |
| 2 | 75 | 4.63 | 0.17 | 3.7 | 0.14 | 3.0 | 0.18 | 3.9 | 0.28 | 6.2 | |
| 3 | 75 | 6.11 | 0.24 | 3.9 | 0.20 | 3.3 | 0.36 | 5.9 | 0.47 | 7.8 | |
| 4 | 75 | 35.89 | 1.25 | 3.5 | 1.46 | 4.1 | 3.26 | 9.1 | 3.78 | 10.5 | |
| 5 | 75 | 55.66 | 2.28 | 4.1 | 1.92 | 3.5 | 4.78 | 8.6 | 5.64 | 10.1 | |
| 6 | 75 | 82.78 | 3.71 | 4.5 | 2.20 | 2.7 | 7.25 | 8.8 | 8.44 | 10.2 | |
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2. Linearity:
The linearity of the analytical measuring interval (AMI) was evaluated for the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent according to CLSI EP06-Ed2.
For the Aptiva APS IgG Reagent, five overlapping dilution series to cover the AMI of each of the aCL IgG and aβ2GPI IgG assays were prepared by mixing human serum samples with high antibody concentrations and samples with low antibody concentrations. Each sample was tested in duplicate using one lot of the Aptiva APS IgG Reagent. The overall testing range for linearity study is from 0.11–382.20 FLU for aCL IgG assay, and 0.11–301.21 FLU for aαβ2GPI IgG. The percent deviation from the weighted least squares regression analysis was used to assess the fit of the regression for each sample and each analyte. The data support the linearity of AMI of 0.29–328.94 FLU for the aCL IgG assay and the AMI of 0.21–256.70 FLU for the aβ2GPI IgG assay, as part of the Aptiva APS IgG Reagent.
For Aptiva APS IgM Reagent, four overlapping dilution series to cover portions of the AMI of each of the aCL IgM and aβ2GPI IgM assays were prepared by mixing human serum samples with high antibody concentrations and samples with low antibody concentrations. Each sample was tested in duplicate using one lot of the Aptiva APS IgM Reagent. The overall testing range for linearity study is from 0.04–118.12 FLU for aCL IgM assay, and 0.04–102.10 FLU for aαβ2GPI IgM. The percent deviation from the weighted least squares regression analysis was used to assess the fit of the regression for each sample and each analyte. The data support the linearity of AMI of 0.10–114.68 FLU for the aCL IgM assay and the AMI of 0.10–95.86 FLU for the aβ2GPI IgM assay, as part of the Aptiva APS IgM Reagent.
3. Hook effect
The hook effect for Aptiva APS IgG Reagent and Aptiva APS IgM Reagent on the Aptiva System was evaluated by testing high positive serum samples for each device: two high aCL IgG samples and two high aβ2GPI IgG samples for the Aptiva APS IgG Reagent; two high aCL IgM samples and two high aβ2GPI IgM samples for the Aptiva APS IgM Reagent.
For the Aptiva APS IgG Reagent, no antigen excess hook effect was observed up to 2645.36 FLU for aCL IgG and 1790.48 FLU for aβ2GPI IgG.
For the Aptiva APS IgM Reagent, no hook effect was observed up to 167.25 FLU for aCL IgM and 126.13 FLU for the aβ2GPI IgM.
4. Analytical Specificity/Interference:
Interference
An interference study was performed according to CLSI EP07-A2 for the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent. A set of three human serum specimens—one positive, one around the cut-off and one negative sample for each assay were used to prepare interferent spiked samples or corresponding control samples without the interfering
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substance. All samples were tested in five replicates using the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent. The percent recovery for each sample spiked with the potential interfering substance was calculated by comparing its result to that of the corresponding control sample without the interfering substance. Based on the results, the following tables display the highest concentration at which no interference was observed for the Aptiva APS IgG Reagent and IgM Reagent assays.
| | Aptiva APS IgG Reagent (aCL IgG / aβ2GPI IgG) | Aptiva APS IgM Reagent (aCL IgM / aβ2GPI IgM) |
| --- | --- | --- |
| Interferent | Concentration without Interference | |
| Endogenous | | |
| Bilirubin, Conjugated | 1.0 mg/mL | 1.0 mg/mL |
| Hemoglobin | 10.00 g/L | 10.00 g/L |
| Triglyceride | 1000.0 mg/dL | 1000.0 mg/dL |
| Cholesterol | 332.5 mg/dL | 332.5 mg/dL |
| RF IgM | 153.4 IU/mL | 153.4 IU/mL |
| Human IgG | 20.0 mg/mL | 20.0 mg/mL |
| Exogenous | | |
| Ibuprofen | 21.9 mg/dL | 21.9 mg/dL |
| Warfarin | 7.5 mg/dL | 7.5 mg/dL |
| Prednisone | 0.0099 mg/dL | 0.0099 mg/dL |
| Acetaminophen | 15.6 mg/dL | 15.6 mg/dL |
| Aspirin | 3.00 mg/dL | 3.00 mg/dL |
| Hydroxychloroquine | 0.465 mg/dL | 0.465 mg/dL |
| Omeprazole | 0.840 mg/dL | 0.840 mg/dL |
| Simvastatin | 0.168 mg/dL | 0.168 mg/dL |
| Heparin | 330 units/dL | 330 units/dL |
# 5. Assay Reportable Range:
The reportable range for the Aptiva APS IgG Reagent and Aptiva APS IgM Reagent is the same as the analytical measuring interval (AMI) for both devices. The AMI for each assay is shown in the table below:
| | Analytical Measuring Interval |
| --- | --- |
| Aptiva APG IgG Reagent | |
| aCL IgG | 0.29 – 328.94 FLU |
| aβ2GPI IgG | 0.21 – 256.70 FLU |
| Aptiva APG IgM Reagent | |
| aCL IgM | 0.10 – 114.68 FLU |
| aβ2GPI IgM | 0.10 – 95.86 FLU |
6. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):
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## Traceability:
There is no international reference material for anti-cardiolipin antibodies and anti-β2-GPI antibodies. Calibrator and control values are directly traceable to in-house reference materials that are used to create the master curves for each assay of the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent.
## Stability:
a. Reagent shelf-life stability: An on-going real-time stability and an accelerated stability study were conducted to establish shelf-life stability for the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent. The study required testing at least three serum samples at different levels for each assay using three lots of reagents at different timepoints. The collected data showed the initial shelf-life of 9 months for the Aptiva APS IgG Reagent and 7 months for the Aptiva IgM Reagent when stored at 2–8°C.
b. Reagent in-use (on-board) stability: An initial in-use stability for the Aptiva APS IgG Reagent and Aptiva APS IgM Reagent was conducted by testing multiple samples with different assay levels at different time points using the reagent stored on board. The in-use (on-board) stability of the Aptiva APS IgG and Aptiva APS IgM Reagents was set at 28 days, with a 14-day recalibration.
c. Reagent shipping stability: A transport simulation study was performed to assess the shipping stability of the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent kits during transport. The study was performed under simulated conditions that the products may potentially be exposed to during transport. The collected data support the reagent packaging mitigates the potential impact of temperature stressing during transport.
d. Sample stability: Five serum samples with different antibody levels were stored at various storage temperatures and tested with the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent at various timepoints. The collected data showed that the sample can be stored up to 14 days at 2–8°C, up to 48 hours at room temperature (20–26°C), and up to five freeze/thaw cycles when stored at -20°C.
## 7. Detection Limit:
Limit of Blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ) were assessed for each analyte in the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent following CLSI EP17-A2.
## LoB:
To determine the LoB, four blank samples were run in five replicates, once a day for three days using two reagent lots, for a total of 60 data points per lot. The LoB was determined for each assay, on each reagent lot separately, at the 95th percentile using the non-parametric method for all analyses. The higher LoB result between the two lots was selected for the final LoB value.
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# LoD:
To determine the LoD for each analyte, four low level samples were assayed in five replicates, twice per day for three days using two reagent lots, to generate a total of 120 data points for each assay on each reagent lot. The LoD was calculated as the $\mathrm{LoB} + 1.65 \times \mathrm{SD}$ of the replicates for the samples separately for each assay on each reagent lot and the highest LoD result was selected for the final LoD value.
# LoQ:
To determine the LoQ for each analyte, four low level samples (different from LoD study) were run in five replicates, twice per day for three days using two reagent lots, to generate 120 data points for each assay on each reagent lot. The LoQ was determined separately for each assay on each reagent lot by calculating the total imprecision of each sample. The LoQ was defined as the lowest concentration level that meets the within-laboratory imprecision of $< 20\%$ for each lot. The greatest LoQ across the two lots was set as the LoQ value and as the lower limit of the AMI for each assay.
The LoB, LoD, and LoQ for the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent are summarized in the following table:
| | LoB (FLU) | LoD (FLU) | LoQ (FLU) |
| --- | --- | --- | --- |
| Aptiva APS IgG Reagent | | | |
| aCL IgG | 0.00 | 0.07 | 0.29 |
| aβ2GPI IgG | 0.02 | 0.09 | 0.21 |
| Aptiva APS IgM Reagent | | | |
| aCL IgM | 0.01 | 0.04 | 0.10 |
| aβ2GPI IgM | 0.03 | 0.06 | 0.10 |
# 8. Assay Cut-Off:
The following cut-off is used for the aCL IgG, a $\beta$ 2GPI IgG assays in the Aptiva APS IgG Reagent and aCL IgM and a $\beta$ 2GPI IgM assays in the Aptiva APS IgM Reagent:
Positive: $\geq 5.00$ FLU
Negative: $< 5.00$ FLU
The cut-off was established based on greater than the 99th percentile of the results obtained on the reference healthy population.
# B Comparison Studies:
# 1. Method Comparison with Predicate Device:
Samples for the Aptiva APS IgG and Aptiva APS IgM method comparison analysis included serum samples from the clinical validation study (see VII.C) that display results within the analytical measuring range of the assay and the respective predicate device(s). Positive percent agreement (PPA), negative percent agreement (NPA), and total percent agreement
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(TPA) with 95% confidence intervals (95%CI) were calculated for each analyte comparison, excluding values that were outside of the measuring ranges of either assay. The results are summarized in the following tables:
## Aptiva APS IgG Reagent
| Method comparison (aCL IgG vs. the predicate device) | | | | |
| --- | --- | --- | --- | --- |
| | HemosIL AcuStar Cardiolipin IgG (Predicate) | | | |
| | | Positive | Negative | Total |
| Aptiva APS IgG Reagent (aCL IgG) | Positive (≥5.0 FLU) | 31 | 7 | 38 |
| | Negative (<5.0 FLU) | 7 | 157 | 164 |
| | Total | 38 | 164 | 202 |
| PPA: 81.6% (31/38) (95% CI: 66.6–90.8%)
NPA: 95.7% (157/164) (95% CI: 91.5–97.9%)
TPA: 93.1% (188/202) (95% CI: 88.7–95.8%) | | | | |
| Method comparison (aβ2GPI IgG vs. the predicate device) | | | | |
| --- | --- | --- | --- | --- |
| | QUANTA Lite aβ2GPI IgG ELISA (Predicate) | | | |
| | | Positive | Negative | Total |
| Aptiva APS IgG Reagent (aβ2GPI IgG) | Positive (≥5.0 FLU) | 44 | 6 | 50 |
| | Negative (<5.0 FLU) | 6 | 52 | 58 |
| | Total | 50 | 58 | 108 |
| PPA: 88.0% (44/50) (95% CI: 76.2–94.4%)
NPA: 89.7% (52/58) (95% CI: 79.2–95.2%)
TPA: 88.9% (96/108) (95% CI: 81.6–93.5%) | | | | |
## Aptiva APS IgM Reagent
| Method comparison (aCL IgM vs. the predicate device) | | | | |
| --- | --- | --- | --- | --- |
| | HemosIL AcuStar Cardiolipin IgM (Predicate) | | | |
| | | Positive | Negative | Total |
| Aptiva APS IgM Reagent (aCL IgM) | Positive (≥5.0 FLU) | 40 | 37 | 77 |
| | Negative (<5.0 FLU) | 6 | 339 | 345 |
| | Total | 46 | 376 | 422 |
| PPA: 87.0% (40/46) (95% CI: 74.3–93.9%)
NPA: 90.2% (339/376) (95% CI: 86.7–92.8%)
TPA: 89.8% (379/422) (95% CI: 86.6–92.3%) | | | | |
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| Method comparison (aβ2GPI IgM vs. the predicate device) | | | | |
| --- | --- | --- | --- | --- |
| | HemosIL AcuStar anti-β2 Glycoprotein-I IgM (Predicate) | | | |
| | | Positive | Negative | Total |
| Aptiva APS IgM Reagent (aβ2GPI IgM) | Positive (≥5.0 FLU) | 24 | 34 | 58 |
| | Negative (<5.0 FLU) | 3 | 183 | 186 |
| | Total | 27 | 217 | 244 |
| PPA: 88.9% (24/27) (95% CI: 71.9–96.1%)
NPA: 84.3% (183/217) (95% CI: 78.9–88.6%)
TPA: 84.8% (207/244) (95% CI: 79.9–88.8%) | | | | |
2. **Matrix Comparison:**
Not applicable. Only human serum specimens are intended use sample type for the Aptiva APS IgG Reagent and Aptiva APS IgM Reagent.
C **Clinical Studies:**
**Aptiva APS IgG Reagent**
The clinical validation study for the Aptiva APS IgG Reagent was performed using a cohort of samples including a total of 526 characterized serum samples. This study cohort included 60 samples from patients with primary antiphospholipid syndrome (pAPS), 62 samples from patients with secondary antiphospholipid syndrome (sAPS), and 404 samples from patients with various types of autoimmune and infectious diseases. All samples were tested with the Aptiva APS IgG Reagent according to the instruction for use. The clinical performance of the Aptiva APS IgG Reagent as an aid in the diagnosis of APS are summarized in the following tables:
| Clinical performance (aCL IgG) | | | | |
| --- | --- | --- | --- | --- |
| | Clinical Diagnosis | | | |
| | | APS | Non-APS | Total |
| Aptiva APS IgG Reagent (aCL IgG) | Positive (≥5.0 FLU) | 66 | 2 | 68 |
| | Negative (<5.0 FLU) | 56 | 402 | 458 |
| | Total | 122 | 404 | 526 |
| Clinical Sensitivity: 54.1% (66/122) (95% CI: 45.3–62.7%)
Clinical Specificity: 99.5% (402/404) (95% CI: 98.2–99.9%) | | | | |
| Clinical performance (aβ2GPI IgG) | | | | |
| --- | --- | --- | --- | --- |
| | Clinical Diagnosis | | | |
| | | APS | Non-APS | Total |
| Aptiva APS IgG Reagent (aβ2GPI IgG) | Positive (≥5.0 FLU) | 65 | 4 | 69 |
| | Negative (<5.0 FLU) | 57 | 400 | 457 |
| | Total | 122 | 404 | 526 |
| Clinical Sensitivity: 53.3% (65/122) (95% CI: 44.5–61.94%)
Clinical Specificity: 99.0% (400/404) (95% CI: 97.5–99.6%) | | | | |
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Distribution of target and differential disease samples and antibody positive rates are shown in the table below:
| Aptiva APS IgG Reagent | | | | | |
| --- | --- | --- | --- | --- | --- |
| Diagnostic Group | N=526 | aCL IgG | | aβ2GPI IgG | |
| | | n | (%) | n | (%) |
| Target diagnosis | 122 | 66 | 54.1% | 65 | 53.3% |
| pAPS | 60 | 33 | 55.0% | 32 | 53.3% |
| sAPS | 62 | 33 | 53.2% | 33 | 53.2% |
| Differential diagnostic controls | 404 | 2 | 0.5% | 4 | 1.0% |
| Infectious Disease | 58 | 0 | 0.0% | 0 | 0.0% |
| PREPI | 37 | 1 | 2.7% | 1 | 2.7% |
| SLE no APS | 27 | 0 | 0.0% | 0 | 0.0% |
| Systemic sclerosis | 12 | 1 | 8.3% | 1 | 8.3% |
| Crohn's Disease | 29 | 0 | 0.0% | 0 | 0.0% |
| Ulcerative Colitis (UC) | 27 | 0 | 0.0% | 0 | 0.0% |
| Rheumatoid Arthritis | 21 | 0 | 0.0% | 1 | 4.8% |
| Fetal Loss no APS | 15 | 0 | 0.0% | 0 | 0.0% |
| Thrombosis no APS | 4 | 0 | 0.0% | 0 | 0.0% |
| ANCA-associated vasculitis (AAV) | 15 | 0 | 0.0% | 0 | 0.0% |
| Autoimmune Thyroid | 30 | 0 | 0.0% | 0 | 0.0% |
| Celiac Disease (CD) | 30 | 0 | 0.0% | 0 | 0.0% |
| COVID-19 related thrombosis | 20 | 0 | 0.0% | 1 | 5.0% |
| Hematologic malignancies | 16 | 0 | 0.0% | 0 | 0.0% |
| Idiopathic thrombocytopenic purpura (ITP) | 17 | 0 | 0.0% | 0 | 0.0% |
| Solid tumor malignancies | 16 | 0 | 0.0% | 0 | 0.0% |
| Deep vein thrombosis | 30 | 0 | 0.0% | 0 | 0.0% |
# Aptiva APS IgM Reagent
The clinical validation study for the Aptiva APS IgM Reagent was performed using a cohort of samples including a total of 689 characterized serum samples. This study cohort included 219 samples from patients with primary antiphospholipid syndrome (pAPS), 72 samples from patients with secondary antiphospholipid syndrome (sAPS), and 398 samples from patients with various types of autoimmune and infectious diseases. All samples were tested with the Aptiva APS IgM Reagent according to the instruction for use. The clinical performance of the Aptiva APS IgM as an aid in the diagnosis of APS are summarized in the following tables:
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| Clinical performance (aCL IgM) | | | | |
| --- | --- | --- | --- | --- |
| | Clinical Diagnosis | | | |
| | | APS | Non-APS | Total |
| Aptiva APS IgM Reagent (aCL IgM) | Positive (≥5.0 FLU) | 80 | 10 | 90 |
| | Negative (<5.0 FLU) | 211 | 388 | 599 |
| | Total | 291 | 398 | 689 |
| Clinical Sensitivity: 27.5% (80/291) (95% CI: 22.7–32.9%)
Clinical Specificity: 97.5% (388/398) (95% CI: 95.4–98.6%) | | | | |
| Clinical performance (aβ2GPI IgM) | | | | |
| --- | --- | --- | --- | --- |
| | Clinical Diagnosis | | | |
| | | APS | Non-APS | Total |
| Aptiva APS IgM Reagent (aβ2GPI IgM) | Positive (≥5.0 FLU) | 72 | 6 | 78 |
| | Negative (<5.0 FLU) | 219 | 392 | 611 |
| | Total | 291 | 398 | 689 |
| Clinical Sensitivity: 24.7% (72/291) (95% CI: 20.1–30.0%)
Clinical Specificity: 98.5% (392/398) (95% CI: 96.8–99.3%) | | | | |
Distribution of target and differential disease samples and antibody positive rates are shown in the table below:
| Aptiva APS IgM Reagent | | | | | |
| --- | --- | --- | --- | --- | --- |
| Diagnostic Group | N=689 | aCL IgM | | aβ2GPI IgM | |
| | | n | (%) | n | (%) |
| Target diagnosis | 291 | 80 | 27.5% | 72 | 24.7% |
| pAPS | 219 | 60 | 27.4% | 52 | 23.7% |
| sAPS | 72 | 20 | 27.8% | 20 | 27.8% |
| Differential diagnosis controls | 398 | 10 | 2.5% | 6 | 1.5% |
| Infectious Disease | 69 | 0 | 0.0% | 0 | 0.0% |
| Myositis | 20 | 1 | 5.0% | 0 | 0.0% |
| Autoimmune Thyroiditis | 35 | 3 | 8.6% | 2 | 5.7% |
| Celiac Disease (CD) | 50 | 0 | 0.0% | 0 | 0.0% |
| Ulcerative Colitis (UC) | 19 | 1 | 5.3% | 1 | 5.3% |
| Rheumatoid Arthritis | 13 | 1 | 7.7% | 1 | 7.7% |
| Atopic Dermatitis | 11 | 0 | 0.0% | 0 | 0.0% |
| Fetal Loss no APS | 27 | 0 | 0.0% | 0 | 0.0% |
| Pre-Eclampsia | 17 | 0 | 0.0% | 0 | 0.0% |
| Thrombosis no APS | 7 | 1 | 14.3% | 1 | 14.3% |
| ANCA-associated vasculitis (AAV) | 15 | 0 | 0.0% | 0 | 0.0% |
| COVID-19 related thrombosis | 20 | 1 | 5.0% | 0 | 0.0% |
| Hematologic malignancies | 16 | 0 | 0.0% | 0 | 0.0% |
| Solid tumor malignancies | 16 | 1 | 6.3% | 1 | 6.3% |
| Idiopathic thrombocytopenic purpura (ITP) | 17 | 0 | 0.0% | 0 | 0.0% |
| Other disease controls | 16 | 0 | 0.0% | 0 | 0.0% |
| Deep vein thrombosis | 30 | 1 | 3.3% | 0 | 0.0% |
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# D Clinical Cut-Off:
Refer to assay cut-off.
# E Expected Values/Reference Range:
To determine the reference range of the Aptiva APS IgG and Aptiva APS IgM, a panel of 200 apparently healthy blood donors (106 females and 94 males, ages 18-70 years, and median age of 37 years) were tested following CLSI EP28-A3c. With the cut-off of 5.0 FLU, no samples tested positive for both the Aptiva APS IgG Reagent and the Aptiva APS IgM Reagent. The results are summarized in the following table:
| Measurand | N | Min (FLU) | Max (FLU) | Medium (FLU) | 97.5thPercentile (FLU) |
| --- | --- | --- | --- | --- | --- |
| Aptiva APS IgG Reagent | | | | | |
| aCL IgG | 200 | 0.29 | 0.42 | 0.29 | 0.29 |
| aβ2GPI IgG | 200 | 0.21 | 0.47 | 0.21 | 0.21 |
| Aptiva APS IgM Reagent | | | | | |
| aCL IgM | 200 | 0.10 | 2.54 | 0.10 | 0.51 |
| aβ2GPI IgM | 200 | 0.10 | 3.11 | 0.10 | 0.47 |
# VIII Proposed Labeling:
The labeling supports the finding of substantial equivalence for this device.
# IX Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
