(368 days)
The 25-Hydroxy Vitamin DS EIA assay is intended for the quantitative determination of 25-hydroxyvitamin D [25(OH)D] and other hydroxylated metabolites in human serum or plasma. Results are to be used in conjunction with other clinical and laboratory data to assist the clinician in the assessment of vitamin D sufficiency in an adult population.
The 25-Hydroxy Vitamin De EIA is a manual assay test and does not require the use of an automated system. The whole assay is performed in a microtitre plate and requires a user to perform each step. The 25-Hydroxy Vitamin De assay is an enzymeimmunoassay for the quantitation of 25(OH)D and other hydroxylated metabolites in serum or plasma. 25uL of each calibrators, controls and samples are diluted with biotin labelled 25(OH)D. The diluted samples are incubated in microtitre wells which are coated with a highly specific sheep 25(OH)D at room temperature before aspiration and washing. Enzyme (horseradish peroxidase) labelled avidin, is added and binds selectively to complexed biotin and, following a further wash step, colour is developed using a chromogenic substrate (TMB). The absorbance of the stopped reaction mixtures are read in a microtitre plate reader, colour intensity developed being inversely proportional to the concentration of 25(OH)D.
The provided document describes the performance characteristics of the 25-Hydroxy Vitamin D EIA assay, but it focuses on analytical and comparative performance rather than a study proving the device meets general acceptance criteria in a clinical setting with human readers. The document is for an in-vitro diagnostic (IVD) device, so the criteria and studies described are relevant to laboratory performance.
Here's an analysis of the acceptance criteria and supporting studies based on the provided text, adapted for an IVD context where appropriate:
1. A table of acceptance criteria and the reported device performance
For IVD devices, "acceptance criteria" are usually internal performance goals set by the manufacturer to demonstrate analytical and clinical performance required for regulatory clearance. The document lists several performance characteristics and provides the corresponding measurements for the candidate device and, in some cases, the predicate device.
| Performance Characteristic | Acceptance Criteria (from text or implied) | Reported Device Performance (Candidate Device) |
|---|---|---|
| Traceability | Traceable to ID-LCMS/MS 25(OH) Vitamin D RMP (VDSP standard) | Traceable to ID-LCMS/MS RMP (VDSP human serum panel) and certified by CDC VDSP |
| Stability (Kit) | 8 months when stored at 2-8°C | 8 months when stored at 2-8°C |
| Stability (Open Vial) | (Implied: adequate for practical use) | Reconstituted Biotin 25(OH)D Solution: 8 weeks (2-8°C, dark) Unused Ab. coated plate strip: 8 weeks (2-8°C, foil pouch) Calibrators, Controls: 8 weeks (2-8°C) Wash Solution: 8 weeks (room temp, after prep) |
| Limit of Blank (LoB) | (Implied: sufficiently low) | 1.3 ng/mL (4.5 nmol/L) |
| Limit of Detection (LoD) | (Implied: sufficiently low) | 2.7 ng/mL (6.9 nmol/L) |
| Limit of Quantitation (LoQ) | (Implied: sufficiently low) | 4.8 ng/mL (12.0 nmol/L) |
| Cross-Reactivity (25(OH)D3) | (Implied: high expected, near 100%) | 95% |
| Cross-Reactivity (25(OH)D2) | (Implied: high expected, near 100%) | 109% |
| Interference (Triglycerides) | No interference up to 475 mg/dL | No interference up to 475 mg/dL |
| Interference (Bilirubin conjugated) | No interference up to 20 mg/dL | No interference up to 20 mg/dL |
| Interference (Haemoglobin) | No interference up to 400 mg/dL | No interference up to 400 mg/dL |
| Interference (HAMA) | No interference up to 1000 ng/mL | No interference up to 1000 ng/mL |
| Interference (Rheumatoid Factor) | No interference up to 800 IU/mL | No interference up to 800 IU/mL |
| Interference (Red Blood Cells) | No interference up to 0.4% | No interference up to 0.4% |
| Interference (Vitamin D Binding Proteins) | No interference up to 2000 ng/dL | No interference up to 2000 ng/dL |
| Interference (Total Protein) | No interference up to 9.2 g/dL | No interference up to 9.2 g/dL |
| Interference (Cholesterol, Total) | No interference up to 500 mg/dL | No interference up to 500 mg/dL |
| Interference (Biotin) | No interference up to 200 nmol/L | No interference up to 200 nmol/L |
| Method Comparison (vs. Predicate) Slope | 0.85 to 1.15 | 0.88 (Passing Bablok), 0.82 (Linear Reg) |
| Method Comparison (vs. Predicate) Intercept | +/- 7 ng/mL | 3.23 ng/mL (Passing Bablok), 4.86 ng/mL (Linear Reg) |
| Method Comparison (vs. Predicate) Correlation (r) | ≥ 0.90 | 0.97 |
| Method Comparison (vs. Reference) Slope | 0.88 to 1.02 (95% CI from study) | 0.96 (Passing Bablok), 0.97 (Deming Reg) |
| Method Comparison (vs. Reference) Intercept | -1.62 to 1.88 ng/mL (95% CI from study) | -0.11 ng/mL (Passing Bablok), -0.84 ng/mL (Deming Reg) |
| Method Comparison (vs. Reference) Correlation (r) | 0.947 (from study) | 0.947 |
| Precision (Total %CV) | (Implied: acceptable for diagnostic assay) | 3.7% to 11.5% across 11.7 to 65.1 ng/mL |
| Linearity (Regression Coefficient R²) | (Implied: close to 1.00) | 1.00 |
| Linearity (Max Deviation) | (Implied: acceptable limits) | -8.8% (>20ng/mL), 2.37 ng/ml (<20ng/mL) |
| Reportable Range | 6.5 to 100 ng/mL | 6.5 to 100 ng/mL (16.3 to 250 nmol/L) |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Precision/Reproducibility: 10 serum samples, assayed using 3 lots of reagents in duplicate, twice per day for a minimum of 20 days (n ≥ 80 replicates per sample). The origin of these samples is not specified.
- Linearity/Assay Reportable Range: Samples containing varying concentrations of 25-hydroxyvitamin D were assayed in replicate of four. The number of unique samples for this study is not explicitly stated, but they were patient samples (high patient sample diluted with a low patient sample). Origin not specified.
- Analytical Specificity (Cross-reactivity): Vitamin D serum samples were spiked with various cross-reactants. Number of samples not specified. Not specified if retrospective or prospective. Origin not specified.
- Analytical Specificity (Interference): Substances spiked into the assay. Number of samples/experiments not specified. Not specified if retrospective or prospective. Origin not specified.
- Method Comparison (vs. Predicate Device):
- Sample Size: n = 195 (patient samples).
- Provenance: Not specified (country/retrospective/prospective).
- Method Comparison (vs. Reference Measurement Procedure - RMP):
- Sample Size: n = 109 independent native serum samples.
- Provenance: Samples were value assigned by the Ghent reference method procedure. Not specified if retrospective or prospective, or country of origin for the samples themselves.
- Matrix Comparison:
- Sample Sizes: SST (n=28), EDTA plasma (n=38), Sodium Heparin plasma (n=28), Lithium Heparin plasma (n=28), Citrate plasma (n=28).
- Provenance: Not specified (country/retrospective/prospective).
- Expected Values/Reference Range:
- Sample Size: 280 apparently healthy adult individuals.
- Provenance: Retrospective. Individuals were "living in geographical diverse regions of the United States to represent a broad spectrum of UV light exposure".
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
For this IVD device (25-Hydroxy Vitamin D EIA assay), the "ground truth" is established by reference methods or the true concentration of the analyte, not typically by expert interpretation from medical images or clinical judgment directly.
- Method Comparison (vs. Reference Measurement Procedure): The "ground truth" for this comparison was established by the Ghent reference method procedure for 25-Hydroxy Vitamin D, and the assay is traceable to the isotope dilution-liquid chromatography/tandem mass spectrometry (ID-LCMS/MS) 25(OH) Vitamin D reference method procedure (RMP) which was used in assigning the target value for the Vitamin D Standardization Program (VDSP single donor human serum panel, itself traceable to NIST SRM 2972). This indicates a highly standardized and validated analytical method, which serves as the "expert" or definitive reference for concentration. The "experts" are the developers and maintainers of these reference methods, typically highly qualified analytical chemists or metrologists, not clinical experts for interpreting results in a diagnostic imaging sense.
- Other studies: For precision, linearity, and specificity, the "ground truth" is inherent to the prepared samples or known concentrations, not established by human experts.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Adjudication methods like "2+1" or "3+1" are typically used in studies involving human interpretation (e.g., radiology reads) where disagreements need to be resolved. This is not applicable to the analytical performance studies of an IVD assay where quantitative results are compared to a reference method or known values. Therefore, none was used in the sense of clinical expert adjudication.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
No MRMC study was done, as this device is an in-vitro diagnostic assay for quantitative laboratory measurement, not an AI-assisted diagnostic imaging tool that involves human readers interpreting images.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This device is a standalone assay. It provides a numerical result for 25-Hydroxy Vitamin D concentration. The performance studies detailed (precision, linearity, LoD, LoQ, method comparisons, interference, cross-reactivity) are all evaluations of this standalone analytical performance, quantifying its accuracy and reliability in measuring the analyte in patient samples. There is no "human-in-the-loop" once the sample is processed by the assay; a user performs the assay steps, but the result generated is direct from the assay's chemical reactions and spectrophotometric reading.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The ground truth used primarily consists of:
- Reference Measurement Procedures (RMP): Specifically, the ID-LCMS/MS method (traceable to NIST SRM 2972) and the Ghent reference method procedure. These are highly accurate and standardized analytical methods for determining the true concentration of 25-Hydroxy Vitamin D.
- Known Concentrations: For studies like linearity, LoB, LoD, LoQ, interference, and cross-reactivity, ground truth is established by preparing samples with known, precise concentrations of the analyte or interfering substances.
8. The sample size for the training set
This document describes a premarket notification (510(k)) for a medical device (an in-vitro diagnostic assay). The concept of a "training set" is typically associated with machine learning or AI models. For an IVD assay, raw materials and assay design are developed through R&D, and then validated with studies like those described. There isn't a "training set" in the sense of data used to train an algorithm. The development and optimization of the assay's components (e.g., antibodies) would occur during the manufacturing process, but the document doesn't provide details on sample sizes used during that phase.
9. How the ground truth for the training set was established
As there isn't a "training set" in the AI/ML context for this IVD assay, this question is not directly applicable. The "ground truth" for the analytical performance studies (as described in point 7) was established using reference measurement procedures and known concentrations.
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August 25, 2015
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
IMMUNODIAGNOSTIC SYSTEMS LTD. MICK HENDERSON RA OFFICER 10 DIDCOT WAY, BOLDON BUSINESS PARK BOLDON, TYNE & WEAR NE35 9PD, GREAT BRITAIN
Re: K142351
Trade/Device Name: 25-Hydroxy Vitamin De EIA Regulation Number: 21 CFR 862.1825 Regulation Name: Vitamin D test system Regulatory Class: II Product Code: MRG Dated: August 14, 2015 Received: August 19, 2015
Dear Mick Henderson:
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 electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
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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/Resourcesfor You/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,
Katherine Serrano -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
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Indications for Use
510(k) Number (if known) K142351
Device Name 25-Hydroxy Vitamin DS EIA
:
Indications for Use (Describe)
The 25-Hydroxy Vitamin DS EIA assay is intended for the quantitative determination of 25-hydroxyvitamin D [25(OH)D] and other hydroxylated metabolites in human serum or plasma. Results are to be used in conjunction with other clinical and laboratory data to assist the clinician in the assessment of vitamin D sufficiency in an adult population.
Type of Use (Select one or both, as applicable)
X Prescription Use (Part 21 CFR 801 Subpart D)
__ Over-The-Counter Use (21 CFR 801 Subpart C)
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| 510k Number | 510(k) SUMMARYK142351 | |
|---|---|---|
| Introduction | determination of substantial equivalence. | According to the requirements of 21CFR807.92, the followinginformation provides sufficient detail to understand the basis for a |
| Submitter | Immunodiagnostic Systems Limited10 Didcot WayBoldon Business ParkBoldonTyne and WearNE35 9PDUnited Kingdom | |
| Contact Person: Mick HendersonPhone: +44 191 5190660Fax: +44 191 5190760Email: mick.henderson@idsplc.com | ||
| Secondary Contact: Mr. R. PrebulaHogan Lovells US LLP,Columbia Square,555 Thirteenth Street, NW,Washington DC | ||
| 20004WashingtonPhone: (202)637 6548Fax: (202)637 5910Email: randy.prebula@hoganlovells.com | ||
| Date prepared:18 August 2015 | ||
| Device Name | ||
| Proprietary names: | 25-Hydroxy Vitamin Dª EIA | |
| Common names: | Vitamin D test | |
| Classification:Regulatory Class: | 21CFR862.1825 Vitamin D Test SystemII | |
| Product Code: | MRG | |
| IDS, OCTEIA 25-OH Vitamin D EIA, (K021163)Predicate Device Name: |
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A. Test Principle:
The 25-Hydroxy Vitamin De EIA is a manual assay test and does not require the use of an automated system. The whole assay is performed in a microtitre plate and requires a user to perform each step.
The 25-Hydroxy Vitamin De EIA assay
The 25-Hydroxy Vitamin De assay is an enzymeimmunoassay for the quantitation of 25(OH)D and other hydroxylated metabolites in serum or plasma. 25uL of each calibrators, controls and samples are diluted with biotin labelled 25(OH)D. The diluted samples are incubated in microtitre wells which are coated with a highly specific sheep 25(OH)D at room temperature before aspiration and washing. Enzyme (horseradish peroxidase) labelled avidin, is added and binds selectively to complexed biotin and, following a further wash step, colour is developed using a chromogenic substrate (TMB).
The absorbance of the stopped reaction mixtures are read in a microtitre plate reader, colour intensity developed being inversely proportional to the concentration of 25(OH)D.
B. Indications For Use:
For In Vitro Diagnostic Use
The 25-Hydroxy Vitamin De EIA assay is intended for the quantitative determination of 25-hydroxyvitamin D [25(OH)D] and other hydroxylated metabolites in human serum or plasma. Results are to be used in conjunction with other clinical and laboratory data to assist the clinician in the assessment of vitamin D sufficiency in an adult population.
Rx Only
C. Comparison with the predicate:
Similarities compared to the chosen predicate device (OCTEIA 25-hydroxy vitamin D EIA)
| PredicateK021163 | Candidate Device | |
|---|---|---|
| Intended Use | The OCTEIA 25-hydroxyvitamin D EIA (25-OH D) kit isan assay for the quantitativemeasurement of 25-Hydroxyvitamin D in serum and plasma. | Same |
| Indications for use | Results are to be used inconjunction with other clinicaland laboratory data to assist the | Same |
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| clinician in the assessment ofvitamin D sufficiency | ||
|---|---|---|
| Analyte | 25-hydroxy vitamin D | Same |
| Reagent storage | 2-8°C | Same |
| Capture | Antibody coated micro plate | Same |
| Calibrator | Low charcoal stripped humanserum containing 25-hydroxyvitamin D and sodium azide as apreservative | Same |
| Sample volume | 25µL | Same |
| Units | nmol/L | Same |
| Kit components | EIA kit consisting of Anti-25-OH D coated plate, Biotinylated25-OH D, Standards (7 levels),kit controls (2 levels), AvidinHRP solution, substrate solution,stop solution and wash solution | Same |
| Calibration | Full standard curve to be runwith all assays | Same |
| Calibration interval | Per assay run | Same |
| Quality Control | Two (2) controls provided | Same |
| Conversion of units | nmol/L x 0.40 = ng/mLng/ml. x 2.5 = nmol/L | Same |
Differences compared to the chosen (FDA cleared; marketed) predicate device
| PredicateK021163 | Candidate Device | |
|---|---|---|
| Antibodies | Sheep anti 25-hydroxy vitaminD. | new source |
| Analytical sensitivity | 5 nmol/L | NA |
| Functional Sensitivity(Limit of Quantitation(LoQ) | NA | 4.8ng/mL (12 nmol/L) |
| Limit of Detection(LoD) | NA | 2.7ng/mL (6.9 nmol/L) |
| Limit of Blank(LoB) | NA | 1.3ng/mL (4.5nmol/L) |
| Precision | Intra-assay Precision n = 105.3% to 6.7% in theconcentration range 39 to165nmol/LInter-assay Precision n = 114.6% to 8.7% in theconcentration range 40 to132nmol/L | Within Run Precision n = 881.9% to 3.7% in theconcentration range 11.7 to65.1 ng/mL (29.3 to 183nmol/L)Total Precision n = 883.7% to 11.6% in theconcentration range 11.7 to65.1ng/mL (29.3 to 183nmol/L) |
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| Specificity, | Specificity | Specificity |
|---|---|---|
| Interfering substances | 25-Hydroxy vitamin D3 | 25-Hydroxy vitamin D3 |
| & Cross Reactivity | 100% | તે તે જેની જેવી સવલતો પ્રાપ્ય થયેલી છે. આ ગામનાં લોકોનો મુખ્ય વ્યવસાય ખેતી, ખેતમજૂરી તેમ જ પશુપાલન છે. આ ગામનાં મુખ્યત્વે ખેતી, ખેતમજૂરી તેમ જ પશુપાલન છે. આ ગામનાં મુખ્યત્વે |
| Performance | PredicateK021163 | Candidate Device |
|---|---|---|
| Specificity,Interfering substances& Cross Reactivity | Interference:HaemoglobinTested up to 1470 mg/dLBilirubinTested up to 513 µmol/LLipidTested up to 5.6 mmol/Ltriglyceride | Interference:HaemoglobinNo interference up to400mg/dLBilirubin, conjugatedNo interference up to 20mg/dLTriglyceride (Intra Lipid)No interference up to475mg/dLTotal ProteinNo interference up to 9.2g/dLHAMANo interference up to1000ng/mLRed Blood CellsNo interference up to 0.4%Rheumatoid FactorNo interference up to800IU/mLVitamin D Binding Protein(Gc globulin)No interference up to 2000ng/mLCholesterol, TotalNo interference up to500mg/dLBiotinNo interference up to200nmol/L |
| Performance | PredicateK021163 | Candidate Device |
| Cross Reactivity25-Hydroxy vitamin D275% | Cross Reactivity25-Hydroxy vitamin D2109% | |
| 24,25-DiHydroxy vitamin D3$\ge$ 100% | 24-25 Di- Hydroxy vitamin D395% | |
| 24,25-(OH)2D391% | ||
| Cholecalciferol (D3)< 0.01% | 3-epi-25-OH Vitamin D3-1% | |
| Cholecalciferol (D2)< 0.30% | 3-epi-25-OH Vitamin D2-1% | |
| 1,25-(OH)2D35% | ||
| 1,25-(OH)2D284% | ||
| Paricalcitol17% | ||
| 25(OH)D395% | ||
| 25(OH)D2109% | ||
| Vitamin D3 (Cholecalciferol)0% | ||
| Vitamin D2 (Ergocalciferol)6% | ||
| Performance | PredicateK021163 | Candidate Device |
| Reference range/Expected Values | 47.7 – 144 nmol/L | Non Supplemented11.2 to 45.9ng/mL28.0 to 114.6 nmol/LSupplemented15.4 to 86.8ng/mL38.5 to 217.1 nmol/LOverall12.3 to 49ng/mL30.7 to 122.5 nmol/L |
| Method comparison | Against a recognisedradioimmunoassayn = 180AC57 = 1.01(x) + 0.7Correlation coefficient (r) =0.9 | Against Predicate devicen = 195Passing Bablok regression:25-Hydroxy Vitamin DS= 0.88x (25-Hydroxy Vitamin D) +3.2 ng/mL (+ 8.1 nmol/L)Pearson correlation coefficient,r: 0.94 |
| Reportable Range | 2ng/mL to 152ng/mL | 6.5 to 100ng/mL |
| Linearity | Mean Measured / Expected102%Range individual dilutions88% to 125% | Linear regression of theobserved concentrations versusthe expected concentrations:Observed = 1.02 x (Expected)+ 0.23 ng/mLObserved = 1.02 x (Expected)+ 0.58 nmol/LRegression coefficient R²:=1.00Maximum deviation; -8.8% forsamples > 20 ng/mL and 2.37ng/ml for samples < 20 ng/mL |
| Sample matrix(primary tube type) | Serum or Plasma (EDTA orHeparin) | Serum (standard samplingtubes or tubes containingserum separating gel) orplasma (EDTA, lithiumheparin, sodium heparin orsodium citrate) |
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D. Performance Characteristics :
-
- Analytical performance:
- a. Precision/Reproducibility:
Precision was determined in accordance with CLSI EP5-A2, "Evaluation of Precision Performance of Quantitative Measurement Methods". 10 serum samples were assayed using 3 lots of reagents in duplicate, twice per day for a minimum of 20 days (n ≥ 80 replicates per sample).
| ng/mL | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| EP Evaluator | ||||||||||
| Within Run | Between Run | Between Day | Total | |||||||
| n = | Mean | SD | %cv | SD | %cv | SD | %cv | SD | %cv | |
| IQC1 | 88 | 19.1 | 0.4 | 1.9% | 0.6 | 3.2% | 0.1 | 0.4% | 0.7 | 3.7% |
| IQC2 | 88 | 43.7 | 0.8 | 1.9% | 0.9 | 4.3% | 0.0 | 0.0% | 2.0 | 4.6% |
| IQC3 | 88 | 65.1 | 2.3 | 3.5% | 4.0 | 6.2% | 1.7 | 2.6% | 4.9 | 7.6% |
| S1 | 88 | 11.7 | 0.4 | 3.4% | 1.3 | 11.0% | 0.0 | 0.0% | 1.4 | 11.5% |
| S2 | 88 | 24.5 | 0.6 | 2.5% | 1.3 | 5.3% | 0.0 | 0.0% | 1.4 | 5.8% |
| S3 | 88 | 40.7 | 1.0 | 2.5% | 2.1 | 5.1% | 0.0 | 0.0% | 2.3 | 5.7% |
| S4 | 88 | 73.2 | 2.7 | 3.7% | 4.0 | 5.5% | 0.6 | 0.8% | 4.9 | 6.6% |
| S5 | 88 | 21.7 | 0.5 | 2.4% | 0.9 | 4.1% | 0.0 | 0.0% | 1.0 | 4.7% |
| S6 | 88 | 51.0 | 1.9 | 3.7% | 3.4 | 6.6% | 0.0 | 0.0% | 3.9 | 7.6% |
| S7 | 88 | 28.3 | 0.8 | 2.7% | 1.7 | 6.2% | 0.0 | 0.0% | 1.9 | 6.7% |
Results from one representative lot is summarized in the table below (n=88)
b. Linearity/assay reportable range:
Linearity was evaluated based on a modified version of CLSI EP-6A, "Evaluation of the Linearity of Quantitative Measurement Procedures". Samples containing varying concentrations of 25-hydroxyvitamin D were assayed in replicate of four. The resulting mean concentrations were compared to predicted concentrations. Samples were prepared by diluting a high patient sample with a low patient sample prior to assay. The linear regression (weighted) of the Observed concentrations versus the expected concentrations is:
Observed = 1.02 x (Expected) + 0.23 ng/mL Observed = 1.02 x (Expected) + 0.58 nmol/L Regression coefficient R == 1.00 Maximum deviation; -8.8% for samples > 20 ng/mL and 2.37 ng/ml for samples < 20 ng/mL
The reportable range of the assay is 6.5 - 100 ng/mL (16.3 - 250 nmol/L). Any value that reads below 6.5 ng/mL (16.3nmol/L) should be reported as "< 6.5 ng/mL (16.3 nmol/L)".
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- Traceability, Stability, Expected values (controls, calibrators, or methods): C.
Traceability:
The 25-Hydroxy Vitamin D assay is traceable to the isotope dilution-liquid chromatography/tandem mass spectrometry (ID-LCMS/MS) 25(OH) Vitamin D reference method procedure (RMP) which was used in assigning the target value for the Vitamin D Standardization Program (VDSP single donor human serum panel. The ID-LCMS/MS RMP is traceable to the National Institute of Standards and Technology Standard Reference Material (SRM) 2972.
The 25-Hydroxy Vitamin DS assay is certified by the CDC Vitamin D Standardization Certification Program (VDSP) http://www.cdc.gov/labstandards/hs.html
Stability
This kit is stable for 8 months when stored at 2-8℃.
| Kit component | After opening or preparation (open vial stability) |
|---|---|
| Biotin 25(OH)D Solution | 8 weeksafter reconstitutionStore at 2-8°C in the dark immediately after use |
| Unused Ab. coated plate strip | 8 weeksStore at 2-8°C in foil pouch withdesiccant sachet |
| Calibrators,Controls | 8 weeksStore at 2-8°C after opening |
| Wash Solution | 8 weeksStore at room temperature (18-25 °C) after preparation |
d. Detection limit:
The limit of blank (LoB), limit of detection (LoD) and limit of quantitation (LoQ) were determined based on guidance from CLSI EP17-A "Protocols for the determination of limits of detection and limits of quantitation".
| Sensitivity | 25OHD Levels |
|---|---|
| LoB | 1.3 ng/mL (4.5 nmol/L) |
| LoD | 2.7 ng/mL (6.9 nmol/L) |
| LoQ | 4.8 ng/mL (12.0 nmol/L) |
e. Analytical specificity:
Cross-reactivity of endogenous 25(OH) vitamin D metabolite. Endogenous 25(OH) vitamin D metabolites were spiked into vitamin D serum samples and analyzed with the 25-Hydroxy Vitamin Do assay.
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| Cross Reactant | Spike Conc. (ng/mL) | Mean % Cross Reactivity |
|---|---|---|
| 25(OH)D3 | 10.0 | 95% |
| 20.0 | ||
| 25(OH)D2 | 10.0 | 109% |
| 20.0 | ||
| 24,25-(OH)2D3 | 4.0 | 91% |
| 6.0 |
Cross-reactivity of exogenous synthetic 25(OH) vitamin D metabolite. Exogenous synthetic 25(OH) vitamin D metabolites were spiked into vitamin D serum samples and analyzed with the 25-Hydroxy Vitamin De assay.
| Cross Reactant | Spike Conc.(ng/mL) | Mean% CrossReactivity |
|---|---|---|
| 3-epi-25(OH) D3 | 100 | -1% |
| 3-epi-25(OH) D2 | 100 | -1% |
| 1,25-(OH)2D3 | 2 | 5% |
| 1,25-(OH)2D2 | 20 | 84% |
| VitaminD3 (Cholecalciferol) | 1000 | 0% |
| VitaminD2 (Ergocalciferol) | 100 | 6% |
| Paricalcitol* | 100 | 17% |
- Paricalcitol interferes with the 25-Hydroxy Vitamin De EIA test. Paricalcitol, when tested, caused a positive bias in sample result.
The following substances do not interfere in the 25-Hydroxy Vitamin DS EIA assay when the concentrations presented in the following table are below the stated threshold.
| Potentially Interfering | Threshold |
|---|---|
| Agent | Concentration |
| Triglycerides | 475 mg/dL |
| Bilirubin (conjugated) | 20 mg/dL |
| Haemoglobin | 400 mg/dL |
| HAMA | 1000 ng/mL |
| Rheumatoid Factor | 800 IU/mL |
| Red Blood Cells | 0.40% |
| Vitamin D BindingProteins | 2000 ng/dL |
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| Total Protein | 9.2g/dL |
|---|---|
| Cholesterol, Total | 500 mg/mL |
| Biotin | 200nmol/L |
-
- Comparison studies:
- a. Method comparison with predicate device:
The 25-Hydroxy Vitamin DS EIA Assay was compared against the 25-Hydroxy Vitamin D EIA assay (K021163) for the quantitative determination of 25-Hydroxy Vitamin D (and other hydroxylated metabolites), following CLSI EP-9A2, "Method Comparison and Bias Estimation Using Patient Samples".
Correlation to 25-Hydroxy Vitamin D EIA, AC57 (K021163)
| Passing Bablok | $y = 0.88x + 3.23$ ng/mL | $y = 0.88x + 8.05$ nmol/L |
|---|---|---|
| Slope, 95% Confidence Interval | 0.86 to 0.91 | 0.86 to 0.91 |
| Intercept, 95% Confidence Interval | 2.71 to 3.83 ng/mL | 6.85 to 9.45 nmol/L |
| Linear Regression | $y = 0.82x + 4.86$ ng/mL | $y = 0.82x + 12.35$ nmol/L |
| Slope, 95% Confidence Interval | 0.80 to 0.84 | 0.80 to 0.84 |
| Intercept, 95% Confidence Interval | 4.14 to 5.57 ng/mL | 10.35 to 13.92 nmol/L |
| Correlation Coefficient, r | 0.97 | 0.97 |
| n | 195 | 195 |
| Difference Plot | -0.61 | -1.53 |
Additional method comparison study was performed against the reference measurement procedure using 109 in dependent native serum samples which has been value assigned by the Ghent reference method procedure. Regression analysis was summarized below:
| ng/mL | nmol/L | |
|---|---|---|
| Passing Bablok | $y = 0.96x - 0.11$ ng/mL | $y = 0.96x - 0.34$ nmol/L |
| Slope, 95% Confidence Interval | 0.88 to 1.02 | 0.88 to 1.02 |
| Intercept, 95% Confidence Interval | -1.62 to 1.88 ng/mL | -4.15 to 4.68 nmol/L |
| Deming Regression | $y = 0.97x - 0.84$ ng/mL | $y = 0.97x - 2.07$ nmol/L |
| Slope, 95% Confidence Interval | 0.90 to 1.04 | 0.90 to 1.04 |
| Intercept, 95% Confidence Interval | -2.75 to 1.08 ng/mL | -6.85 to 2.71 nmol/L |
| Correlation Coefficient, r | 0.947 | 0.947 |
| n | 109 | 109 |
| Diffrence Plot | -1.77 | -4.42 |
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b. Matrix comparison:
Summary of the statistical methods used for alternative blood tube types to serum blood tube using a paired tube comparison is shown below.
Passing-Bablok analysis of the test and comparator assays was performed, taking the slope, intercept and correlation coefficient (with 95 % confidence intervals) and difference bias plot.
| SST | EDTA | Sodium Heparin | |
|---|---|---|---|
| n | 28 | 38 | 28 |
| Passing bablok | $y=0.99x+0.18 g/mL$ | $y=0.97x+0.60ng/mL$ | $y=1.07x-0.47ng/mL$ |
| Slope,95% confidence level | 0.95 to 1.03 | 1.00 to 1.01 | 1.00 to 1.10 |
| Intercept, 95% confidencelevel | -0.17 to 0.65ng/mL | -0.15 to 1.04ng/mL | -1.21 to 0.68ng/mL |
| Correlation Coefficient r | 0.99 | 1.00 | 0.99 |
| Mean Bias | 0.41 | 0.07 | 1.11 |
| Lithium Heparin | Citrate | |
|---|---|---|
| n | 28 | 28 |
| Passing Bablok | Y=1.04x -0.22 ng/mL | Y=1.03x -0.70 ng/mL |
| Slope, 95% confidence level | 1.01 to 1.08 | 0.98 to 1.06 |
| Intercept, 95% Confidence level | -0.73 to 0.60 ng/mL | -1.36 to 0.49 ng/mL |
| Correlation Coefficient, r | 1.00 | 0.99 |
| Mean Bias | 1.50 | 0.43 |
The design criterion was that the slope must be 0.85 to 1.15 and the intercept +/- 7 ng/mL and r ≥0.90.
Serum separator tubes (SST), EDTA plasma, Sodium Heparin plasma, Lithium Heparin plasma and citrate plasma tube data do not present any new issues of safety or effectiveness for the 25-Hydroxy Vitamin De EIA assay.
3. Expected values/Reference range:
An expected values study performed according to the non-parametric method in CLSI protocol C28-A2.
Samples from 280 apparently light skin and dark skin healthy male adults (71.1%) and female adults (28.9%) aged 21-77 years living in geographical diverse regions of the United States to represent a broad spectrum of UV light exposure in the intended population were assayed in the 25-Hydroxy Vitamin Do Assay. Samples were from individuals with normal values for intact PTH, calcium, phosphate, and TSH, and not taking any interfering medications. The following ranges were determined using the 25-Hydroxy Vitamin De assay and are provided for information only. The 95 % reference interval for apparently healthy adults, were calculated by a non-parametric
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method following guidance from CLSI C28-A3 " Defining, Establishing and Verifying Reference Intervals in the Clinical Laboratory".
Obtained normal adults range:12.3 to 49.0 ng/mL (30.7 to 122.5 nmol/L) (n=280)
| n | % | Observed Sample Range(ng/mL) | Median(ng/mL) | |
|---|---|---|---|---|
| Non-supplemented | 219 | 78.2% | 11.2 to 45.9 | 25.1 |
| Northern US | 116 | 41.4% | 10.3 to 35.1 | 22.6 |
| Southern US | 103 | 36.8% | 14.6 to 48.0 | 29.5 |
| Supplemented | 61 | 21.8% | 15.4 to 86.8 | 30.2 |
| Overall | 280 | 100% | 12.3 to 49.0 | 26.0 |
Observed sample ranges were:
| n | % | Observed Sample Range(nmol/L) | Median(nmol/L) | |
|---|---|---|---|---|
| Non-supplemented | 219 | 78.2% | 28.0 to 114.6 | 62.8 |
| Northern US | 116 | 41.4% | 25.6 to 87.6 | 56.5 |
| Southern US | 103 | 36.8% | 36.6 to 120.0 | 73.9 |
| Supplemented | 61 | 21.8% | 38.5 to 217.1 | 75.5 |
| Overall | 280 | 100% | 30.7 to 122.5 | 65.0 |
The above ranges should be considered as guidelines only; it is recommended that each laboratory establish its own expected range based for its own patient population.
The 95% reference interval was calculated by a non-parametric method following C28-A2. The following range was obtained:
12.3 to 49.0 ng/mL (n = 280) Normal Adults 30.7 to 122.5 nmol/L (n = 280)
The package insert states that there is no universal agreement on the optimal concentration of 250HD. Ranges should be based on clinical decision values that apply to both sexes of all ages rather than population based reference ranges for 250HD.
E. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
§ 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.