(212 days)
The LOCI Vitamin D Total assay is an in vitro diagnostic test for the quantitative measurement of total 25(OH)yitamin D in human serum and plasma on the Dimension® EXL™ integrated chemistry system with LOCI® Module. Measurements of vitamin D are used in the assessment of vitamin D sufficiency.
The LOCI VITD CAL is an in vitro diagnostic product for the calibration of the Vitamin D (VITD) Total assay on the Dimension® EXL™ integrated chemistry system with LOCI® module.
LOCI Vitamin D Total assay:
The LOCI Vitamin D Total assay is a homogeneous competitive chemiluminescent immunoassay based on LOCI technology. The assay measures the total 25(OH)vitamin D concentration [comprising both 25(OH)vitamin D2 and 25(OH)vitamin D3] in both serum and plasma. LOCI Vitamin D Total reagents include a releasing reagent, biotinylated monoclonal antibody, and two synthetic bead reagents. Patient sample is incubated with the releasing reagent to release 25(OH)vitamin D molecules from the vitamin D-binding proteins. The reaction mixture is then incubated with biotinylated antibody to form a 25(OH)vitamin D/biotinylated antibody complex.
Chemibeads containing 25(OH)vitamin D3 analog and chemiluminescent dye are added to remove the excess free biotinylated antibody. Streptavidin-coated Sensibeads containing a photosensitive dye are added to bind the biotinylated antibody. Aqqregates of the Chemibead analog/biotinylated antibody/streptavidin Sensibeads are formed as a result. Illumination of the reaction mixture by light at 680 nm generates singlet oxygen from the Sensibeads, which diffuses into the Chemibeads and triagers a chemiluminescent reaction. The resulting chemiluminescent signal is measured at 612 nm and is inversely proportional to the concentration of total 25(OH)vitamin D in the sample.
LOCI VITD CAL:
The LOCI VITD CAL is a five level, liquid, single analyte, frozen product, which is stored at -15 ℃ to -25 ℃. The calibrator matrix consists of processed human serum with preservatives and stabilizers. Level 1 is a zero level, while levels 2 3, 4, and 5 contain approximately 12, 30, 75, and 165 ng/mL respectively. Each lot of calibrators will have lot specific assigned values assigned from master pool levels that are traceable by method correlation to Ghent University's ID-LC/MS/MS 25(OH)vitamin D Reference Method Procedure (RMP). The ID-LC/MS/MS RMP is traceable to the NIST SRM 2972.
Here's an analysis of the provided text regarding the LOCI Vitamin D Total Assay and LOCI VITD CAL, focusing on acceptance criteria and the supporting studies:
Summary of Acceptance Criteria and Device Performance for LOCI Vitamin D Total Assay
Unfortunately, the provided document does not explicitly state predetermined "acceptance criteria" for each performance characteristic in a table format, nor does it provide a direct statement "proving the device meets acceptance criteria."
Instead, the document describes the methods and presents the results of various performance studies. The implication is that these results demonstrate the device's acceptable performance for its intended use, based on generally accepted analytical performance standards in the medical device industry (e.g., CLSI guidelines).
However, I can extract the reported performance and infer what aspects would likely be critical for acceptance.
1. Table of Acceptance Criteria (Inferred) and Reported Device Performance
| Performance Characteristic | Inferred Acceptance Criterion (Typical for IVDs) | Reported Device Performance (LOCI Vitamin D Total Assay) |
|---|---|---|
| Method Comparison | Slope ~1.0, Intercept ~0.0, r > 0.95 | Slope: 1.06 (95% CI: 1.01 to 1.12) Intercept: 0.44 ng/mL (95% CI: -0.54 to 1.42) r-Value: 0.977 |
| Repeatability (within-run precision) | %CV < 10% (typically lower for immunoassays) | QC (Low): 3.1% CV QC (Level 1): 2.6% CV QC (Level 2): 1.9% CV Serum 1: 5.6% CV Serum 2: 2.6% CV Serum 3: 2.1% CV Plasma 2: 1.8% CV |
| Within-Lab Precision (total precision) | %CV < 15% (typically lower for immunoassays) | QC (Low): 5.4% CV QC (Level 1): 5.2% CV QC (Level 2): 4.1% CV Serum 1: 8.7% CV Serum 2: 5.0% CV Serum 3: 4.1% CV Plasma 2: 3.1% CV |
| Linearity | Slope ~1.0, Intercept ~0.0, r > 0.99, % bias < 10% | Slope: 1.02 Intercept: 1.4 ng/mL r: 0.998 % Bias: Within allowable 10% deviation |
| Recovery | Typically 90-110% | 25(OH)D2 added to 28.3 ng/mL: 95% 25(OH)D3 added to 28.3 ng/mL: 89% 25(OH)D2 added to 54.7 ng/mL: 94% 25(OH)D3 added to 54.7 ng/mL: 90% |
| Limit of Detection (LoD) | As low as clinically relevant | 1.3 ng/mL [3.3 nmol/L] (with <5% false positives/negatives) |
| Limit of Quantitation (LoQ) | As low as clinically relevant, with acceptable precision | 5.0 ng/mL [12.5 nmol/L] at ≤20% CV |
| Interference (HIL & other substances) | % Bias < 10% (for non-interfering substances) | Hemolysis: Interferes at 500 mg/dL (11-19% bias) Bilirubin (unconj.): Interferes at 80 mg/dL (12-13% bias at lower VitD levels) Bilirubin (conj.): Interferes at 40 mg/dL (11-17% bias) Lipemia: Interferes at 500 mg/dL (10-11% bias at lower VitD levels) Cholesterol: Interferes at 350 mg/dL (10-12% bias) Non-interfering: Acetaminophen, Ascorbic Acid, Biotin, Heparin, Ibuprofen, Rheumatoid Factor, Salicylic Acid, Triglycerides, Uric Acid. |
| HAMA Interference | % Bias < 10% | Max mean % bias of 10% observed on a sample with 5.0 ng/mL vitamin D containing 106 ng/mL HAMA. Mean bias of 2.8% with 161,000 ng/mL HAMA at 28.3 ng/mL VitD. |
| Serum Plasma Equivalency | Slope ~1.0, Intercept ~0.0, r > 0.95 | Lithium heparin plasma vs serum: Slope 0.99, Intercept 0.1, r 0.992 EDTA plasma vs serum: Slope 0.98, Intercept 1.4, r 0.997 Serum SST vs serum: Slope 0.99, Intercept 0.5, r 0.997 |
| Cross-Reactivity | Specificity to 25(OH)vitamin D2/D3, low cross-reactivity with other D metabolites | 25(OH)D2: 94-95% 25(OH)D3: 89-90% 1,25(OH)2D2: 1.3-151.9% (high at low VitD) 1,25(OH)2D3: -224.5-1.7% (variable) Paricalcitol: 71-94% |
2. Sample Size Used for the Test Set and Data Provenance
- Method Comparison:
- Sample Size: 163 remnant de-identified human serum samples.
- Data Provenance: Not explicitly stated, but "human serum samples" implies human origin. "Remnant de-identified" suggests retrospective data.
- Repeatability and Within Lab Precision:
- Sample Size: Testing performed with Tri-Level Vitamin D Plus QC (3 levels) and 4 human serum/plasma samples (Serum 1, Serum 2, Serum 3, Plasma 2). Each sample/QC was analyzed as a single test from two independent cups, over 20 days with 2 runs per day.
- Data Provenance: Not specified, but laboratory-controlled samples/QCs and potentially remnant human samples.
- Linearity:
- Sample Size: One sample with high concentration serially diluted. Each dilution assayed in n=5 replicates.
- Data Provenance: Laboratory prepared samples.
- Recovery:
- Sample Size: Two separate serum samples (baseline 28.3 ng/mL and 54.7 ng/mL) were spiked.
- Data Provenance: Human serum.
- Detection Capability (LoD, LoB):
- Sample Size: 120 determinations (60 blank and 60 low-level replicates).
- Data Provenance: Laboratory prepared blank and low-level samples.
- Interference Testing (HIL & Non-Interfering Substances):
- Sample Size: Not explicitly stated per interferent, but tested at three levels of vitamin D concentrations (13.9-16.9 ng/mL, 28.4-32.0 ng/mL, 70.2-77.3 ng/mL).
- Data Provenance: Laboratory prepared samples spiked with interferents.
- HAMA Interference:
- Sample Size: 20 samples containing vitamin D (5.0 ng/mL to 87.5 ng/mL) with varying concentrations of HAMA (8 ng/mL to 161,000 ng/mL). Mean n=5 for bias calculations.
- Data Provenance: Human samples containing HAMA.
- Serum Plasma Equivalency:
- Sample Size: 70 matched lithium heparin plasma, K2 EDTA plasma, serum separator tube (SST), and red top serum samples. 8 were fresh native, 62 frozen (8 of these split and spiked).
- Data Provenance: Human patient samples (U.S. geographical locations, potentially diverse, during different seasons). Indicated as remnant, de-identified and includes both fresh and frozen samples. This is a mix of prospective (freshly drawn) and retrospective (remnant, frozen) data from human patients in the US.
- Cross-Reactivity:
- Sample Size: Not explicitly stated per cross-reactant, but tested at specified concentrations.
- Data Provenance: Laboratory prepared samples spiked with cross-reactants.
- Apparently Healthy Population (Expected Values):
- Sample Size: 252 adults (246 not taking supplements, 6 taking).
- Data Provenance: Human serum samples collected from subjects residing in diverse U.S. geographical locations, during different seasons.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- Ground Truth for Method Comparison: The "ground truth" for the method comparison study was established by the ID-LC-MS/MS 25(OH) vitamin D Reference Measurement Procedure (RMP) from Ghent University, which is traceable to the NIST Standard SRM2972. This is a highly specialized analytical method, not typically performed by "experts" in the sense of a medical professional consensus. It's a gold-standard laboratory technique.
- Other Studies: For other performance characteristics, the ground truth is based on the known concentrations of controls, calibrators, spiked samples, or reference materials, which are established through rigorous analytical methodology rather than expert consensus on a clinical case.
4. Adjudication Method for the Test Set
This type of information (e.g., 2+1, 3+1 for clinical consensus) is not applicable to an in vitro diagnostic (IVD) assay product like the LOCI Vitamin D Total Assay. Adjudication methods are typically used in imaging studies or clinical trials where human interpretation of data (e.g., images, patient symptoms) is subject to variability and requires consensus among experts to establish a "ground truth" or clinical outcome. For IVD assays, the "ground truth" is largely analytical, based on reference methods or known concentrations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size of Human Reader Improvement
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is primarily relevant for medical imaging AI devices where human readers interpret images, and the AI serves as an aid. The LOCI Vitamin D Total Assay is an automated in vitro diagnostic assay, where the output is a quantitative measurement, not an image requiring human interpretation or a "reader."
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
The entire set of performance characteristic studies for the LOCI Vitamin D Total Assay (e.g., precision, linearity, method comparison, interference) evaluates the standalone performance of the assay. It's an automated system (Dimension EXL integrated chemistry system with LOCI Module), and the results presented reflect the assay's output without direct human "in-the-loop" interpretation for each individual test result beyond the initial setup and quality control.
7. The Type of Ground Truth Used
The ground truth used for the critical method comparison study and calibrator traceability is traceability to a reference measurement procedure (RMP) and standard reference materials (SRM):
- For Method Comparison: Ghent University's ID-LC-MS/MS 25(OH) vitamin D Reference Measurement Procedure (RMP), traceable to NIST SRM 2972. This is considered a highly accurate and precise analytical "gold standard."
- For Calibrators (LOCI VITD CAL): Internal standards traceable by method correlation to Ghent University's ID-LC-MS/MS 25(OH) vitamin D RMP, which is traceable to NIST SRM 2972.
- For other studies (e.g., precision, linearity, recovery, detection capability, interference): Known concentrations of controls, calibrators, or prepared spiked samples.
8. The Sample Size for the Training Set
The document does not provide information about a "training set" because this is an in vitro diagnostic assay, not an AI/ML algorithm that requires an explicit training phase on a dataset of patient results. The development process for such assays involves extensive R&D, reagent formulation, and analytical validation but not "training" in the machine learning sense.
9. How the Ground Truth for the Training Set Was Established
Since there is no explicit "training set" in the context of an AI/ML algorithm, this question is not applicable as per the understanding derived from the document. The "ground truth" for the analytical performance of the assay and its calibrators is established as described in point 7.
{0}------------------------------------------------
Image /page/0/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is a stylized image of a human figure, represented by three curved lines, with its arms outstretched.
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002 March 16, 2017
SIEMENS HEALTHCARE DIAGNOSTICS KATHLEEN DRAY-LYONS REGULATORY AND CLINICAL AFFAIRS SPECIALIST 500 GBC DRIVE P.O. BOX 6101 NEWARK DE 19714
Re: K162298
Trade/Device Name: LOCI Vitamin D Total Assay LOCI VITD CAL Regulation Number: 21 CFR 862.1825 Regulation Name: Vitamin D test system Regulatory Class: II Product Code: MRG, JIT Dated: February 3, 2017 Received: February 6, 2017
Dear Kathleen Dray-Lyons:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug. and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA), You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the
{1}------------------------------------------------
electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours,
Kellie B. Kelm -S
for Courtney H. Lias, Ph.D. Director Division of Chemistry and Toxicology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health
Enclosure
{2}------------------------------------------------
Indications for Use
Form Approved: OMB No. 0910-0120 Expiration Date: January 31, 2017 See PRA Statement below.
510(k) Number (if known) K162298
Device Name
LOCI Vitamin D Total Assay
Indications for Use (Describe)
The LOCI Vitamin D Total assay is an in vitro diagnostic test for the quantitative measurement of total 25(OH)yitamin D in human serum and plasma on the Dimension® EXL™ integrated chemistry system with LOCI® Module. Measurements of vitamin D are used in the assessment of vitamin D sufficiency.
| Type of Use (Select one or both, as applicable) | |
|---|---|
| ☑ Prescription Use (Part 21 CFR 801 Subpart D) | ☐ Over-The-Counter Use (21 CFR 801 Subpart C) |
CONTINUE ON A SEPARATE PAGE IF NEEDED.
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov
"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."
{3}------------------------------------------------
Indications for Use
510(k) Number (if known) K162298
Device Name
LOCI VITD CAL
Indications for Use (Describe)
The LOCI VITD CAL is an in vitro diagnostic product for the calibration of the Vitamin D (VITD) Total assay on the Dimension® EXL™ integrated chemistry system with LOCI® module.
| Type of Use (Select one or both, as applicable) | ||
|---|---|---|
| ☒ Prescription Use (Part 21 CFR 801 Subpart D)☐ Over-The-Counter Use (21 CFR 801 Subpart C) | ☒ Prescription Use (Part 21 CFR 801 Subpart D) | ☐ Over-The-Counter Use (21 CFR 801 Subpart C) |
| ☒ Prescription Use (Part 21 CFR 801 Subpart D) | ||
| ☐ Over-The-Counter Use (21 CFR 801 Subpart C) |
CONTINUE ON A SEPARATE PAGE IF NEEDED.
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov
"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."
{4}------------------------------------------------
Siemens Healthcare Diagnostics LOCI Vitamin D Total Assay LOCI VITD CAL 510(k) Premarket Notification
510(k) Summary
This summary of 510(k) safety and effectiveness information is submitted in accordance with the requirements of SMDA 1990 and 21 CFR §807.92.
The assigned 510(k) number is: K162298
- Manufacturer's Name, Address, Telephone, and Contact Person, Date of 1. Preparation
| Applicant: | Siemens Healthcare Diagnostics Inc.500 GBC Drive | |
|---|---|---|
| M/S 514 | ||
| P.O. Box 6101 | ||
| Newark, DE 19714 |
| Contact Information: | Siemens Healthcare Diagnostics Inc.500 GBC DriveP.O. Box 6101Newark, DE 19714 |
|---|---|
| ----------------------------- | ------------------------------------------------------------------------------------------- |
Attn: Kathleen Dray-Lyons Tel: 781-826-4551 Email: kathleen.a.dray-lyons@siemens.com
Date of Preparation: March 15, 2017
2. Device Names:
- o LOCI Vitamin D Total Assay
- O LOCI VITD CAL
Classification:
- 21 CFR §862.1825; Vitamin D test system, Class II O
- 21 CFR §862.1150; Calibrator Secondary, Class II O
Product Code:
- o MRG
- JIT O
Panel:
- Clinical Chemistry O
- Clinical Chemistry O
3. Identification of the Predicate Devices:
ADVIA Centaur Vitamin D Total (VitD) Assay - K110586
{5}------------------------------------------------
ADVIA Centaur Vitamin D Total (VitD) Calibrators - K110586
4. Device Description:
LOCI Vitamin D Total assay:
The LOCI Vitamin D Total assay is a homogeneous competitive chemiluminescent immunoassay based on LOCI technology. The assay measures the total 25(OH)vitamin D concentration [comprising both 25(OH)vitamin D2 and 25(OH)vitamin D3] in both serum and plasma. LOCI Vitamin D Total reagents include a releasing reagent, biotinylated monoclonal antibody, and two synthetic bead reagents. Patient sample is incubated with the releasing reagent to release 25(OH)vitamin D molecules from the vitamin D-binding proteins. The reaction mixture is then incubated with biotinylated antibody to form a 25(OH)vitamin D/biotinylated antibody complex.
Chemibeads containing 25(OH)vitamin D3 analog and chemiluminescent dye are added to remove the excess free biotinylated antibody. Streptavidin-coated Sensibeads containing a photosensitive dye are added to bind the biotinylated antibody. Aqqregates of the Chemibead analog/biotinylated antibody/streptavidin Sensibeads are formed as a result. Illumination of the reaction mixture by light at 680 nm generates singlet oxygen from the Sensibeads, which diffuses into the Chemibeads and triagers a chemiluminescent reaction. The resulting chemiluminescent signal is measured at 612 nm and is inversely proportional to the concentration of total 25(OH)vitamin D in the sample.
LOCI VITD CAL:
The LOCI VITD CAL is a five level, liquid, single analyte, frozen product, which is stored at -15 ℃ to -25 ℃. The calibrator matrix consists of processed human serum with preservatives and stabilizers. Level 1 is a zero level, while levels 2 3, 4, and 5 contain approximately 12, 30, 75, and 165 ng/mL respectively. Each lot of calibrators will have lot specific assigned values assigned from master pool levels that are traceable by method correlation to Ghent University's ID-LC/MS/MS 25(OH)vitamin D Reference Method Procedure (RMP). The ID-LC/MS/MS RMP is traceable to the NIST SRM 2972.
5. Device Intended Use:
LOCI Vitamin D Total ssay:
The LOCI Vitamin D Total assay is an in vitro diagnostic test for the quantitative measurement of total 25(OH)vitamin D in human serum and plasma on the Dimension® EXL™ integrated chemistry system with LOCl® Module. Measurements of vitamin D are used in the assessment of vitamin D sufficiency.
LOCI VITD CAL:
The LOCI VITD CAL is an in vitro diagnostic product for the calibration of the total Vitamin D (VITD) assay on the Dimension® EXL™ integrated chemistry system with LOCI® module.
{6}------------------------------------------------
Measuring Range
6. Medical device to which equivalence is claimed:
Substantial Equivalence:
The LOCI Vitamin D Total assay is substantially equivalent to the ADVIA Centaur Vitamin D Total (VitD) assay cleared under K110586. The LOCI VITD CAL is substantially equivalent to the ADVIA Centaur Vitamin DTotal (VitD) Calibrators (K110586).
Comparison to the predicate:
LOCI Vitamin D Total Assay:
A comparison of the similarities and differences between the currently marketed ADVIA Centaur Vitamin D Assay (predicate) versus the proposed LOCI VITD Total assay is provided in the table below.
ADVIA Centaur Vitamin D Total Assay Predicate Proposed Attributes LOCI VITD Total Assay ADVIA Centaur Vitamin D Total Assay (K110586) The LOCI Vitamin D Total The ADVIA Centaur® Intended Use Vitamin D Total (VitD) assay is an in vitro assay is for in vitro diagnostic test for the quantitative measurement of diagnostic use in the total 25-hydroxyvitamin D quantitative determination (25-OH-D) in human serum of total 25(OH)vitamin D in and plasma on the human serum and plasma Dimension® EXL™ (EDTA, lithium-heparin, integrated chemistry system sodium heparin) using the with LOCI® Module. ADVIA Centaur systems. The ADVIA Centaur VitD Measurements of vitamin D are used in the assessment assay is intended as an aid of vitamin D sufficiency. in the determination of vitamin D sufficiency. Assay format Competitive Immunoassay Same Detection Direct Chemiluminescent Same Technology Antibody Sheep Monoclonal Mouse Monoclonal Sample size 8 ul 20 ul Analyzers Dimension EXL with LM, ADVIA Centaur, ADVIA Dimension EXL with LM-Centaur XP, and ADVIA PMT and Dimension EXL Centaur XPT systems 200 systems Sample type Serum, EDTA plasma, and Serum Plasma ( EDTA. litium heparin plasma lithium heparin and sodium
5.0 - 150.0 ng/mL
heparin)
4.2 to 150 ng/mL
Similarities and Differences LOCI Vitamin D Total Assay versus
{7}------------------------------------------------
LOCI VITD CAL:
A comparison of the similarities and differences between the currently marketed ADVIA Centaur Vit D Calibrator (predicate) versus the proposed LOCI VITD CAL is provided in the table below.
Similarities and Differences LOCI VITD CAL versus ADVIA Centaur VitD Calibrators
| Feature | ProposedLOCI VITD CAL | PredicateADVIA Centaur VitD Calibrators(K110586) |
|---|---|---|
| Intended Use | The LOCI VITD CAL is an in vitrodiagnostic product for the calibrationof the total Vitamin D (VITD) assayon the Dimension® EXL™integrated chemistry system withLOCI® module. | The ADVIA Centaur Vitamin DTotal (VitD) Calibrators is for in vitrodiagnostic use in calibrating ADVIACentaur® systems Vitamin D Total(VitD) assay. |
| Calibrator base | Human serum | Human plasma |
| Calibrator form | Liquid | Lyophilized |
| Traceable to: | Standardized using internalstandards traceable by methodcorrelation to Ghent University's ID-LC-MS/MS 25 OH vitamin DReference Method Procedure(RMP) which is traceable to NISTSRM 2972. | Internal standards which aretraceable to the LC-MS/MS25(OH)vitamin D. |
| Number of levels | Five | Two |
| Packaging Content | 2 vials: Level 1 (1.5 mL), Level 2 (2.0mL), Level 3, 4, 5, (1.5 mL) per vial | 2 vials Low - 2 mL per vial2 vials High -2 mL per vial |
| Storage | -25 to -15°C | 2° to 8°C |
7. Performance Characteristics
Method Comparison versus the ID-LC-MS/MS:
LOCI Vitamin D Total assay on the Dimension EXL™ with LM system was compared to vitamin D values obtained from the University of Ghent using the ID-LC-MS/MS 25(OH) vitamin D Reference Measurement Procedure (RMP), which is traceable to the NIST Standard SRM2972. A split sample method comparison between the LOCI Vitamin D Total assay versus ID-LC-MS/MS was performed with 163 remnant de-identified human serum samples across the assay range (5.0 - 150.0 ng/mL). Analysis of the results using standard Passing Bablok regression yielded the following:
{8}------------------------------------------------
Passing Bablok regression:
| Method | N | ID-LC-MS/MSSampleRangeAnalyzed(ng/mL) | Slope(95% CI) | Interceptng/mL(95% CI) | r -Value* |
|---|---|---|---|---|---|
| LOCI Vitamin D Totalversus ID-LC-MS/MS | 163 | 5.2 – 126.1 | 1.06(1.01 to 1.12) | 0.44(-0.54 to 1.42) | 0.977 |
- Correlation coefficient (r) was obtained from ordinary least squares regression.
Repeatability and Within Lab Precision:
Testing was performed over twenty (20) days, two (2) runs per day, a single test from two (2) independent cups were analyzed for each test material using one lot of LOCI Vitamin D Total assay on the Dimension® EXL™ with LM analyzer . Analysis of variance (ANOVA) was used to evaluate the data consistent with the recommendations of CLSI EP05-A3. Typical precision observed is summarized below.
| Mean | Repeatability | Within-Lab Precision | |||
|---|---|---|---|---|---|
| Material | ng/mL | SD | %CV | SD | %CV |
| Tri-Level Vitamin D Plus | |||||
| QC (Low) | 18.9 | 0.58 | 3.1 | 1.01 | 5.4 |
| QC (Level 1) | 38.7 | 1.02 | 2.6 | 2.02 | 5.2 |
| QC (Level 2) | 89.6 | 1.72 | 1.9 | 3.67 | 4.1 |
| Serum 1 | 8.2 | 0.46 | 5.6 | 0.71 | 8.7 |
| Serum 2 | 29.4 | 0.76 | 2.6 | 1.46 | 5.0 |
| Serum 3 | 76.5 | 1.63 | 2.1 | 3.11 | 4.1 |
| Plasma 2 | 25.2 | 0.44 | 1.8 | 0.78 | 3.1 |
Repeatability and Within-Lab Results
Linearity
Linearity across the assay range, 5.0 - 150.0 ng/mL [12.5 - 375.0 nmol/L] was confirmed by testing a sample with a high concentration of vitamin D and serially diluting with a sample of low concentration vitamin D. Each dilution was assayed in replicates of n=5. Linear regression of observed (y) vs. expected values(x) vielded a slope of 1.02, an intercept of 1.4 ng/mL and a correlation coefficient (r) of 0.998. Percent bias between observed and predicted values was within the allowable 10% deviation from the linear fit.
Recovery
Known amounts of 25(OH)vitamin Dz (30 ng/mL [75.0 nmol/L]) and 25(OH)vitamin-D3 (30 ng/mL [75.0 nmol/L]) were added to separate serum samples containing vitamin D at 28.3 ng/dL [70.8 nmol/L] and 54.7 ng/mL [136.8 nmol/L].
{9}------------------------------------------------
| Vitamin D at 28.3 ng/mL [70.8 nmol/L] | ||
|---|---|---|
| Added | Amount added ng/mL [nmol/L] | % Recovery |
| 25(OH)vitamin D2 | 30.0 [75.0] | 95 |
| 25(OH)vitamin D3 | 30.0 [75.0] | 89 |
| Vitamin D at 54.7 ng/mL [136.8 nmol/L] | ||
| Added | Amount added ng/mL [nmol/L] | % Recovery |
| 25(OH)vitamin D2 | 30.0 [75.0] | 94 |
| 25(OH)vitamin D3 | 30.0 [75.0] | 90 |
The calculated percent recoveries are listed below:
Detection Capability
The Limit of Detection (LoD) for the VITD assay is 1.3 ng/mL [3.3 nmol/L], determined consistent with CLSI guideline EP17-A2 Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures and with proportions of false positives (q) less than 5% and false negatives (ß) less than 5%; based on 120 determinations, with 60 blank and 60 low level replicates. The Limit of Blank (LoB) is 0.8 ng/mL [2.0 nmol/L].
Limit of Quantitation
The limit of quantitation (LoQ) was determined consistent with the CLSI Guideline EP17-A2. TheLoQ for the VITD assay is 5.0 ng/mL [12.5 nmol/L] at a total precision of ≤20% CV. LoQ is defined as the lowest concentration of 25(OH)vitamin D that can be detected at total precision CV of ≤20%.
Interference Testing
Interference testing was performed according to CLSI EP07-A2: Interference Testing in Clinical Chemistry to determine the effect of various endogenous and exogenous substances on the LOCI Vitamin D Total assay. For all interferents, the percent bias was determined by testing a control sample without the interferent and comparing it to the value obtained from a test sample to which the potential interferent had been added. Interferents were tested at three levels of vitamin D concentrations: 13.9-16.9 ng/mL, 28.4-32.0 ng/mL and 70.2-77.3 ng/mL. For each spiked sample, the % recovery was determined. Using 10% as the allowable clinically acceptable threshold for interference, the data below summarizes the concentration of interfering substance tested where there is no interference and the concentration of the interfering substance where interference is first observed.
Hemolysis, Icterus, Lipemia (HIL) Interference
Bias is the difference in the results between the control sample (without the interferent) and the test sample (contains the interferent) expressed in percent. Bias exceeding 10% is considered interference.
{10}------------------------------------------------
Siemens Healthcare Diagnostics LOCI Vitamin D Total Assay LOCI VITD CAL 510(k) Premarket Notification
| Substance Tested | Substance Concentration | Vitamin Dng/mL | Bias*% |
|---|---|---|---|
| Hemoglobin(hemolysate) | Hemoglobin (monomer)250 mg/dL [0.155 mmol/L] | 15.0 | 5 |
| 31.7 | 9 | ||
| 75.1 | 8 | ||
| 500 mg/dL [0.31 mmol/L] | 15.0 | 11 | |
| 31.7 | 19 | ||
| 75.1 | 13 | ||
| Bilirubin(unconjugated) | 40 mg/dL [684.5 µmol/L] | 13.5 | 7 |
| 27.3 | 7 | ||
| 66.7 | 8 | ||
| 80 mg/dL [1368 µmol/L] | 13.5 | 13 | |
| 27.3 | 12 | ||
| 66.7 | 6 | ||
| Bilirubin(conjugated) | 20 mg/dL [342 µmol/L] | 14.9 | 7 |
| 31.7 | 4 | ||
| 75.3 | 3 | ||
| 40 mg/dL [684 µmol/L] | 14.9 | 17 | |
| 31.7 | 12 | ||
| 75.3 | 11 | ||
| Lipemia(Intralipid) | 300 mg/dL [3 g/L] | 14.9 | -5 |
| 32.3 | -6 | ||
| 75.9 | -5 | ||
| 500 mg/dL [5 g/L] | 14.9 | -10 | |
| 32.3 | -11 | ||
| 75.9 | -8 |
- Analyte results should not be corrected based on this bias.
Non-Interfering Substances
The following substances were evaluated for interference using CLSI EP07-A2® and found not to interfere with the VITD assay when present in serum at the concentrations indicated. Inaccuracies (biases) due to these substances do not exceed 10% at vitamin D concentrations of 13.9 – 16.9 ng/mL, 28.4 – 32.0 ng/mL and 70.2 – 77.3 ng/mL.
| Substance | Test Concentration |
|---|---|
| Acetaminophen | 20 mg/dL |
| Ascorbic Acid | 3 mg/dL |
| Biotin | 200 ng/mL |
| Cholesterol | 300 mg/dL |
{11}------------------------------------------------
Siemens Healthcare Diagnostics LOCI Vitamin D Total Assay LOCI VITD CAL 510(k) Premarket Notification
| Dextran 40 | 6000 mg/dL |
|---|---|
| Hemoglobin | 250 mg/dL |
| Heparin | 3 U/mL |
| Ibuprofen | 30 mg/dL |
| Lipemia (Intralipid) | 300 mg/dL |
| Protein (Albumin) | 5 g/dL |
| Protein (Total) | 15.9 g/dL |
| Rheumatoid Factor | 500 IU/mL |
| Salicylic Acid | 65 mg/dL |
| Triglycerides | 686 mg/dL |
| Uric Acid | 20 mg/dL |
Human Anti-Mouse Antibodies (HAMA): Human Anti-Mouse Antibodies (HAMA):
20 samples containing vitamin D at 5.0 ng/mL [12.5 nmol/L] to 87.5 ng/mL [218.7 nmol/L] with varying concentrations of HAMA, from 8 nq/mL to 161,000 ng/mL were tested for HAMA interference. Mean (n=5) percent bias of 2.8% was observed on a sample with a vitamin D concentration of 28.3 ng/mL [70.7 nmol/L] containing 161,000 ng/mL of HAMA. Maximum mean (n=5) percent bias of 10% was observed on a sample with a vitamin D concentration of 5.0 ng/mL [12.5 nmol/L] containing 106 ng/mL of HAMA.
Interfering Substances:
Bias is the difference in the results between the control sample (without the interferent) and the test sample (contains the interferent) expressed in percent. *Bias exceeding 10% is considered interference.
Total Protein at 19 g/dL causes a decrease in the vitamin D concentration by 6% at 14.3 ng/mL, 11% at 30.9 ng/mL and 12% at 77.3 ng/mL.
Hemoglobin at 500 mg/dL causes an increase in the vitamin D concentration by 11% at 15 ng/mL, 19% at 31.7 nq/mL and 13% at 75.1 ng/mL.
Unconjugated bilirubin at 80 mg/dL causes an increase in the vitamin D concentration by 13% at 13.5 ng/mL, 12% at 27.3 ng/mL and 6% at 66.7 ng/mL.
Conjugated bilirubin at 40 mg/dL causes an increase in vitamin D concentration by 17% at 14.9 ng/mL, 12% at 31.7 ng/mL and 11% at 75.3 ng/mL.
Lipemia (Intralipid) at 500 mg/dL causes a decrease in vitamin D concentration by 10% at 14.9 ng/mL, 11% at 32.3 ng/mL and 8% at 75.9 ng/mL.
Cholesterol at 350 mg/dL causes a decrease in vitamin D concentration by 10% at 25.2 ng/mL [63.0 nmol/L] and 12% at 64.0 mg/dL [160.0 nmol/L].
*Analyte results should not be corrected based on observed bias. See additional HIL results under Specificity section.
{12}------------------------------------------------
Serum Plasma Equivalency
Matched lithium heparin plasma, K2 EDTA plasma, serum separator tube (SST) and red top serum samples were collected from 70 patients. Out of the 70 matched serum/plasma sets, 8 were freshly drawn native samples, 62 were frozen and of these eight sets were split and spiked with 25-hydroxyvitamin D3 to cover the upper range of the assay. The results were analyzed by standard Passing Bablok regression and Least Squares (Standard Linear Regression). The correlation coefficient (r) was obtained by linear regression. A summary of the results is presented below.
| Sample Comparison | Slope | Interceptng/mL[nmol/L] | CorrelationCoefficient | n | Minng/mL[nmol/L] | Maxng/mL[nmol/L] |
|---|---|---|---|---|---|---|
| Lithium heparin plasmavs serum (red top) | 0.99 | 0.1 [0.3] | 0.992 | 70 | 11.5 [28.7] | 146.4[366.0] |
| EDTA plasmavs serum (red top) | 0.98 | 1.4 [3.4] | 0.997 | 70 | 11.6 [29.0] | 142.5[356.2] |
| Serum SSTvs serum (red top) | 0.99 | 0.5 [1.2] | 0.997 | 70 | 11.4 [28.5] | 148.6[371.5] |
Cross Reactivity
Cross reactivity testing was performed to determine the effect of potential crossreactants on the LOCI Vitamin D Total assay using CLSI EP07-A2. Percent crossreactivity was calculated as follows:
% Cross-reactivity = [measured vitamin D] - [control vitamin D] x 100 [cross-reactant]
The following substances were evaluated for cross-reactivity with the VITD assay when present in serum at the vitamin D concentrations listed in the following table.
| Cross- Reactant | Cross-ReactantConcentration(ng/mL) | % Cross-reactivity @Vitamin D Concentration | % Cross-reactivity @Vitamin D Concentration |
|---|---|---|---|
| Vitamin D2 (ergocalciferol) | 1000 | 0.1 @ 27.5 ng/mL [68.8 nmol/L] | -0.1 @ 52.0 ng/mL [130.0 nmol/L] |
| Vitamin D3 (cholecalciferol) | 1000 | -0.1 @ 27.5 ng/mL [68.8 nmol/L] | 0.1 @ 52.0 ng/mL [130.0 nmol/L] |
| * 1,25(OH)2vitamin D2 | 0.5 | 151.9 @ 27.5 ng/mL [68.8 nmol/L] | 1.3 @ 52.0 ng/mL [130.0 nmol/L] |
| * 1,25(OH)2vitamin D3 | 0.5 | 1.7 @ 27.5 ng/mL [68.8 nmol/L] | -224.5 @ 52.0 ng/mL [130.0 nmol/L] |
| 3-epi-25(OH)vitamin D3 | 100 | 3.9 @ 27.5 ng/mL [68.8 nmol/L] | 2.5 @ 52.0 ng/mL [130.0 nmol/L] |
| Paricalcitol | 24 | 93.8 @ 28.8 ng/mL [72.0 nmol/L] | 70.8 @ 54.7 ng/mL [136.8 nmol/L] |
Cross-reactivity
{13}------------------------------------------------
| 1αOH Vitamin D3 (alfacalcidol) | 3000 | 0.1 @ 26.5 ng/mL [66.3 nmol/L] | 0.0 @ 51.6 ng/mL [129.0 nmol/L] |
|---|---|---|---|
| 24, 25(OH)2vitamin D3 | 60 | 2.5 @ 26.5 ng/mL [66.3 nmol/L] | 1.2 @ 51.6 ng/mL [129.0 nmol/L] |
| 25(OH)vitamin D2 | 30 | 95.1 @ 28.3 ng/mL [70.8 nmol/L] | 94.1 @ 54.7 ng/mL [136.8 nmol/L] |
| 25(OH)vitamin D3 | 30 | 88.6 @ 28.3 ng/mL [70.8 nmol/L] | 90.1 @ 54.7 ng/mL [136.8 nmol/L] |
*1,25(OH), vitamin D2 and 1,25(OH), vitamin D3 were tested at supra-physiological concentrations.
Expected Values:
30.0 – 100.0 ng/mL [75.0 – 250.0 nmol/L]
Vitamin D levels may vary according to factors such as geography, season, or the patient's health, diet, age, ethnic origin, use of vitamin D supplementation or environment. To assure proper representation of specific populations, each laboratory should establish its own reference intervals.
Health Based Reference Values:
Health-based reference values based on Clinical Guidelines Subcommittee of the Endocrine Society Task Force are recommended to replace population based reference values. A review of the available literature suggests that the recommendations for 25(OH)vitamin D levels are summarized in the table below. Consult the listed references for discussion of vitamin D toxicity levels.
| Vitamin D Status | Range, Adult25(OH)vitamin Dng/mL[nmol/L] |
|---|---|
| Deficient | < 20 [<50] |
| Insufficient | 20 - < 30 [50 - <75] |
| Sufficient | 30 - 100 [75 - 250] |
Observed Values in an Apparently Healthy Population:
Data using the LOCI Vitamin D Total assay were obtained on serum samples collected from 252 adults: 246 adults not taking supplements containing vitamin D, and 6 adults taking supplements containing vitamin D. To represent a broad spectrum of UV light exposure in intended use population, the blood samples tested were collected during different seasons and from subjects residing in diverse U.S. geographical locations. Samples with abnormal values for PTH, calcium, magnesium, phosphorus, and TSH were excluded from this study.
Based on the 95% confidence interval, the following values were established following CLSI quideline EP28-A3c.
The following 25(OH)vitamin D values were obtained:
{14}------------------------------------------------
| Median | 28.3 ng/mL [70.8 nmol/L] |
|---|---|
| Observed 95% interval(2.5th and 97.5th percentiles) | 13.9 - 61.0 ng/mL[34.8 - 152.5 nmol/L] |
Calibrator Traceability:
The LOCI Vitamin D Total assay is standardized using internal standards which are traceable to the ID-LC/MS/MS 25(OH)vitamin D Reference Method Procedure (RMP). The ID-LC/MS/MS is traceable to the National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 2972.
8. Conclusion:
The LOCI Vitamin D Total assay and LOCI VITD CAL are substantially equivalent to the predicate devices based on intended use, principle and the performance characteristics above.
§ 862.1825 Vitamin D test system.
(a)
Identification. A vitamin D test system is a device intended for use in clinical laboratories for the quantitative determination of 25-hydroxyvitamin D (25-OH-D) and other hydroxylated metabolites of vitamin D in serum or plasma to be used in the assessment of vitamin D sufficiency.(b)
Classification. Class II (special controls). Vitamin D test systems must comply with the following special controls:(1) Labeling in conformance with 21 CFR 809.10 and
(2) Compliance with existing standards of the National Committee on Clinical Laboratory Standards.